Educational, supportive and behavioural interventions to improve usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea

Kathleen Askland; Lauren Wright; Dariusz R Wozniak; Talia Emmanuel; Jessica Caston; Ian Smith

doi:10.1002/14651858.CD007736.pub3

. 2020 Apr 7;2020(4):CD007736. doi: 10.1002/14651858.CD007736.pub3

Educational, supportive and behavioural interventions to improve usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea

Kathleen Askland ¹, Lauren Wright ^1,², Dariusz R Wozniak ³, Talia Emmanuel ¹, Jessica Caston ^1,^✉, Ian Smith ³

Editor: Cochrane Airways Group

PMCID: PMC7137251 PMID: 32255210

Abstract

Background

Although highly effective in the treatment of obstructive sleep apnoea (OSA), continuous positive airway pressure (CPAP) is not universally accepted by users. Educational, supportive and behavioural interventions may help people with OSA initiate and maintain regular and continued use of CPAP.

Objectives

To assess the effectiveness of educational, supportive, behavioural, or mixed (combination of two or more intervention types) strategies that aim to encourage adults who have been prescribed CPAP to use their devices.

Search methods

Searches were conducted on the Cochrane Airways Group Specialised Register of trials. Searches are current to 29 April 2019.

Selection criteria

We included randomised controlled trials (RCTs) that assessed intervention(s) designed to inform participants about CPAP/OSA, to support them in using CPAP, or to modify their behaviour to increase use of CPAP devices.

Data collection and analysis

We assessed studies to determine their suitability for inclusion in the review. Data were extracted independently and were entered into RevMan for analysis. 'Risk of bias' assessments were performed, using the updated 'Risk of bias 2' tool, for the primary outcome, CPAP usage. Study‐level 'Risk of bias' assessments were performed using the original 'Risk of bias' tool. GRADE assessment was performed using GRADEpro.

Main results

Forty‐one studies (9005 participants) are included in this review; 16 of these studies are newly identified with updated searches. Baseline Epworth Sleepiness Scale (ESS) scores indicate that most participants suffered from excessive daytime sleepiness. The majority of recruited participants had not used CPAP previously. When examining risk of bias for the primary outcome of hourly machine usage/night, 58.3% studies have high overall risk (24/41 studies), 39.0% have some concerns (16/41 studies), and 2.4% have low overall risk (1/41 studies).

We are uncertain whether educational interventions improve device usage, as the certainty of evidence was assessed as very low. We were unable to perform meta‐analyses for number of withdrawals and symptom scores due to high study heterogeneity.

Supportive interventions probably increase device usage by 0.70 hours/night (95% confidence interval (CI) 0.36 to 1.05, N = 1426, 13 studies, moderate‐certainty evidence), and low‐certainty evidence indicates that the number of participants who used their devices ≥ 4 hours/night may increase from 601 to 717 per 1000 (odds ratio (OR), 1.68, 95% CI 1.08 to 2.60, N = 376, 2 studies). However, the number of withdrawals may also increase from 136 to 167 per 1000 (OR 1.27, 95% CI 0.97 to 1.66, N = 1702, 11 studies, low‐certainty evidence). Participants may experience small improvements in symptoms (ESS score ‐0.32 points, 95% CI ‐1.19 to 0.56, N = 470, 5 studies, low‐certainty evidence), and we are uncertain whether quality of life improves with supportive interventions, as the certainty of evidence was assessed as very low.

When compared with usual care, behavioural interventions produce a clinically‐meaningful increase in device usage by 1.31 hours/night (95% CI 0.95 to 1.66, N = 578, 8 studies, high‐certainty evidence), probably increase the number of participants who used their machines ≥ 4 hours/night from 371 to 501 per 1000 (OR 1.70, 95% CI 1.20 to 2.41, N = 549, 6 studies, high‐certainty evidence), and reduce the number of study withdrawals from 146 to 101 per 1000 (OR 0.66, 95% CI 0.44 to 0.98, N = 939, 10 studies, high‐certainty evidence). Behavioural interventions may reduce symptoms (ESS score ‐2.42 points, 95% CI ‐4.27 to ‐0.57, N = 272, 5 studies, low‐certainty evidence), but probably have no effect on quality of life (Functional Outcomes of Sleep Questionnaire (FOSQ), standardised mean difference (SMD) 0.00, 0.95% CI ‐0.26 to 0.26, N = 228, 3 studies, moderate‐certainty evidence). We are uncertain whether behavioural interventions improve apnoea hypopnoea index (AHI), as the certainty of evidence was assessed as very low.

We are uncertain if mixed interventions improve device usage, increase the number of participants using their machines ≥ 4 hours/night, reduce study withdrawals, improve quality of life, or reduce anxiety symptoms, as the certainty of evidence for these outcomes was assessed to be very low. Symptom scores via the ESS could not be measured due to considerable heterogeneity between studies.

Authors' conclusions

In CPAP‐naïve people with OSA, high‐certainty evidence indicates that behavioural interventions yield a clinically‐significant increase in hourly device usage when compared with usual care. Moderate certainty evidence shows that supportive interventions increase usage modestly. Very low‐certainty evidence shows that educational and mixed interventions may modestly increase CPAP usage. The impact of improved CPAP usage on daytime sleepiness, quality of life, and mood and anxiety scores remains unclear since these outcomes were not assessed in the majority of included studies. Studies addressing the choice of interventions that best match individual patient needs and therefore result in the most successful and cost‐effective therapy are needed.

Plain language summary

Do supportive, educational and behavioural interventions improve usage of continuous positive airway pressure in adults with obstructive sleep apnoea?

What is obstructive sleep apnoea (OSA) and continuous positive airway pressure (CPAP)?

Obstructive sleep apnoea (OSA) is a condition that causes interrupted breathing during sleep. People with OSA spend more time in light sleep and less time in deep sleep and consequently experience daytime sleepiness, which may affect their daily life.

Continuous positive airway pressure (CPAP) is a treatment that delivers pressurised air to keep the airway open. CPAP treatment involves a machine with three main parts: a device that fits over nose and mouth, a tube that connects the mask to the device's motor; and a motor that blows air into the tube.

Review question

We already know that CPAP treats OSA effectively in most people by improving symptoms resulting from OSA. However many people do not use their CPAP machine as much as is recommended. We wanted to look at interventions designed to educate and motivate people with OSA to use their CPAP machines more.

Study characteristics

We looked at evidence from randomised, parallel‐group, controlled studies. Following a comprehensive literature search and assessment of trials, we included 41 studies (number of participants = 9005). Most people experienced excessive daytime sleepiness and had newly diagnosed OSA. Duration of studies ranged from 28 days to two years.

Results

We grouped the trials into those that gave people a) education, b) a supportive intervention, c) behavioural intervention, and d) a mixed intervention (using all thee techniques).

We found that all types of interventions increase CPAP usage with varying levels of certainty. Behavioural therapy increases machine usage by 79 minutes per night, and ongoing supportive interventions probably increase machine use by about 42 minutes per night. Educational and mixed interventions may potentially improve machine usage, however the certainty of this evidence is very low.

We also wanted to look at other outcomes such as daytime sleepiness using the Epworth Sleepiness Scale (ESS), quality of life, depression, and apnoea hypopnoea index (measurement of pauses in breathing and slow or shallow breathing). Not all included studies consistently examined these other outcomes, however behavioural interventions may reduce daytime sleepiness.

Studies generally recruited people who were new to CPAP.

Quality of the evidence

The quality of evidence for improved CPAP adherence varied considerably across studies and study types. We were confident that the behavioural interventions improve adherence for around 70 minutes per night. The quality of evidence for educational, supportive, and mixed interventions was not as strong. The quality of evidence for OSA‐related symptoms including daytime sleepiness, quality of life, anxiety or depression was affected by the low number of studies that measured these outcomes.

Summary of findings

Background

Description of the condition

Obstructive sleep apnoea (OSA) is a common sleep‐related breathing disorder characterised by transient interruption of ventilation caused by complete or partial occlusion of the upper airway. Prolonged airway occlusion may lead to oxygen desaturation, which reduces vascular elasticity, increases coagulability and blood pressure, and predisposes to atherosclerosis (Gagnon 2014). The hypoxia and subsequent reoxygenation caused by OSA can increase blood brain barrier permeability, resulting in neurotoxicity and both medical and neuropsychiatric consequences (Bucks 2013; Canessa 2011; Devita 2017; Lochhead 2010; Olaithe 2013; Osorio 2015; Pan 2014; Stranks 2016; Verstraeten 2004; Yaffe 2011). Additionally, recurrent hypoxia and increased inspiratory effort lead to sleep fragmentation and frequent arousals from sleep.

For many individuals, these physiological changes and sleep fragmentation collectively lead to a range of symptoms: excessive daytime sleepiness (Schwab 2013), mood alterations (Garbarino 2018; Jackson 2018), impairment of cognition and memory (Delhikar 2019; Gagnon 2019; Olaithe 2013; Olaithe 2018), and changes in driving competence (Gagnon 2014; Karimi 2015; Phillipson 1993; Schwab 2013; Tregear 2009). Furthermore, OSA is associated with cardiovascular, cerebrovascular and metabolic co‐morbidities (Dong 2018; Gami 2005; Hashmi 2014; Harsch 2004; Marin 2005; Mokhlesi 2016; Peppard 2000; Punjabi 2009; Schwab 2013; Senaratna 2016; Young 2002; Young 2002a; ; ;), as well as increased mortality (Gami 2005; Marin 2005; Marshall 2008; Marshall 2014; Punjabi 2009; Yaggi 2005; Young 2008).

Phenotyping of OSA severity (mild, moderate and severe) is commonly designated by apnoea hypopnoea index (AHI) (> 5 and ≤15, 15 to 30, > 30). However, OSA is a heterogeneous disorder with different risk factors, clinical presentations, pathophysiology and morbidity (Sutherland 2018). AHI is not the only parameter characterising OSA severity. Recently developed measures of hypoxic burden may better predict cardiovascular mortality associated with OSA (Azarbarzin 2019). Patients with excessive daytime sleepiness are not only at a higher risk of cardiovascular complications, but also have significantly diminished quality of life (Mazzotti 2019). Finally, degree of daytime symptom is not tightly correlated with AHI, so patients with AHI in the mild range may experience significant impairment and patients with high AHI may be relatively asymptomatic (Garbarino 2018b; Zinchuk 2017).

Description of the intervention

The usual first line treatment for moderate to severe OSA is continuous positive airway pressure (CPAP) (Schwab 2013; Kennedy 2019), which involves the use of an airflow generator to provide a constant stream of pressurised air to splint open and maintain patency of the upper airway during the inspiratory and expiratory phases of breathing. When used throughout the entirety of sleep, CPAP eliminates nearly 100% of obstructive apneas/hypopnoeas for the majority of treated patients (Reeves‐Hoche 1994; Sawyer 2011; Sullivan 1981).

Consistent application of CPAP therapy improves the quality of sleep, normalises sleep architecture (Canessa 2011; Baker 2016), reduces daytime sleepiness, enhances neurobehavioural performance (Ancoli‐Israel 2008; Bucks 2013; Canessa 2011; Dalmases 2014; Dalmases 2015; Olaithe 2013; Zimmerman 2006); and reduces the risk of motor vehicle crashes (Findley 2000; Giles 2006; Gurubhagavatula 2017t; Hack 2000; Karimi 2015; Tregear 2009). Longitudinal studies have indicated that CPAP treatment has a protective effect on cardiovascular outcomes; patients who are compliant with CPAP achieve better blood pressure control (Haentjens 2007; Marin 2012; Martinez‐Garcia 2012; Pedrosa 2013; Pepperell 2002; Thunstrom 2016), and have reduced the risk of cardiovascular events (Campos‐Rodriguez 2014; Marin 2005; Martinez‐Garcia 2012; Myhill 2012; Wang 2017). Furthermore, adequate adherence to CPAP may slow cognitive decline (Richards 2019), and have a role in the prevention and treatment of acute stroke (Bravata 2011; Faheem 2018; Martinez‐Garcia 2009). However, it should be noted that this evidence has yet to be corroborated through randomised controlled trials (RCTs). The largest and most recent systematic review and meta‐analysis (Yu 2017) of the effect of CPAP on cardiovascular outcomes found no significant association. Notably CPAP usage was < 4 hours/night in the majority of (and all large) included RCTs. Similar nonsignficant findings were found by the SAVE trial (McEvoy 2016); both of these studies, as well as their proposed implications, are discussed at length in Appendix 1.

Despite the widespread recommendation of CPAP in the management of OSA (Fleetham 2011; Giles 2006; Patil 2019; Schwab 2013), concerns have arisen about its initial and continued acceptance among people who have to use it on a long‐term basis (i.e. the majority of patients diagnosed with OSA ). Reported adherence to CPAP ranges from 17% to 85% (Crawford 2014; Finkel 2009; Lewis 2004; Libman 2017; Lindberg 2006; Pépin 1999; Rotenberg 2016; Somers 2008; Weaver 2010; Young 2009). Eight per cent to 15% of patients refuse to accept the treatment after a single night's use, and some case series report an abandonment rate of up to 50% within one year (Bollig 2010; Krieger 1992). Frequently cited side effects leading to CPAP refusal include general discomfort, nasal congestion, abdominal bloating, mask leaks, claustrophobia, and inconvenience of regular usage (Pepin 1995). Poor adherence may also be related to the fact that CPAP requires a substantial and long‐term behavioural change. The difficulty of accomplishing such change may be further compounded by the high rates of comorbid depressive and anxiety symptoms found among patients with OSA (Chirinos 2017; Jackson 2018; Ohayon 2003; Saunamaki 2007). Moreover, CPAP therapy is not reimbursed in many countries (particularly for those with less severe OSA symptoms), further discouraging initiation of treatment, despite proven effectiveness.

Previously, CPAP use was measured through subjective self‐report or observations made within a clinical setting, each presenting its own bias. Self‐reported adherence is often overestimated and inaccurate, and how a patient behaves in a clinical setting is not generalisable to real world behaviour (Kribbs 1993). Technological advances have dramatically improved the accuracy of, and removed bias from adherence measurement through internalised digital counters or electronic microchip, now standard within CPAP devices. Despite this, the number of hours per night and the frequency of usage required to achieve and maintain therapeutic effectiveness are not well established.

Thresholds for "effective" CPAP usage may depend on the desired health benefit, which vary significantly between patients and relative to baseline severity of OSA (Bollig 2010; Campos‐Rodriguez 2005; Sawyer 2011;Stradling 2000; Wang 2017; Weaver 2007; Zimmerman 2006; ; ). Six to eight hours each night is a common clinical prescription for CPAP, but many studies use a threshold of four hours/night to define 'adherence’ (Lewis 2004; Richards 2007). This threshold likely emerged from early seminal studies (Reeves‐Hoche 1994; Kribbs 1993; Engleman 1994), in which average use was reported in the range of four hours/night, although the authors did not suggest this represented adequate or effective use. Unfortunately, not only has this threshold been widely employed in clinical trials, but it has directly impacted clinical practice in ways likely unintended by original or subsequent investigators. For example, several commonly‐used CPAP devices automatically display a happy face (or other positive feedback) on the user interface once they have reached a use threshold of four hours in a 24‐hour cycle. Additionally, some 'payors' will only cover the costs associated with CPAP for patients who use their device at or above an arbitrary (Schwab 2013) minimum of four hours per night on 70% of nights during an initiation period (e.g. Centers for Medicare and Medicaid Services; Mehrtash 2019). These practices, meant to encourage use, may have serious consequences for those aiming to address longstanding symptoms, risk factors or conditions.

Evidence suggests effectiveness of CPAP follows a dose‐response curve with benefit accruing at different thresholds for different outcomes. For example, Wang 2017 found that CPAP use < 4 hours/night improved daytime sleepiness, four to six hours/night improved all measured symptoms (sleep quality, daytime sleepiness, fatigue and depressive symptoms) while use of ≥ 6 hours produced significantly still greater improvements in all measured domains. Average nightly AHI is reduced by any CPAP use, but whether it reduces AHI to 'subthreshold' severity (AHI < 5) will depend upon baseline AHI, duration of CPAP use, and duration of sleep without CPAP (i.e. unrecorded time). However, increased use surpassing four hours/night has been associated with improvement in sleep architecture and arousal outcomes, reductions in blood pressure (Yang 2015), and reductions in the risk of cardiovascular and cerebrovascular events, while improved cognition and memory and decreased mortality (from the limited data available) likely require greater than six hours/night (Campos‐Rodriguez 2005; Zimmerman 2006). As such, maximising total CPAP use (i.e. to the full amount of recommended nightly sleep for adults, ˜8 hours/night) is optimal and preferred.

How the intervention might work

A substantial amount of studies have investigated predictors of CPAP adherence related to patient characteristics, disease characteristics, and CPAP technology. Research has demonstrated that perceived self‐efficacy, confidence, and motivation are both targetable and modifiable (Bandura 1982; Bandura 1986; Bandura 2004; Miller 1994), and correlate well with sustained and successful treatment (Mehrtash 2019). Moreover, social factors, including marital status, partner involvement and attitudes towards treatment, and partner's sleep quality, have been shown to positively influence CPAP adherence (Mehrtash 2019; Lewis 2004). Lastly, early adoption of CPAP treatment (i.e. within the first week to month of CPAP prescription) has been shown to predict long‐term adherence behaviour (Aloia 2007; Chervin 1997).

From these predictors, various interventions to improve initial acceptance and subsequent CPAP adherence have been proposed, each varying in duration, intensity, frequency and modality. Some approaches emphasise that increasing knowledge of OSA, CPAP and associated health outcomes may directly promote CPAP adherence. Targeting social and supportive factors, other interventions aim to quickly troubleshoot problems that occur during CPAP treatment and provide regular feedback and encouragement from automated prompts, peers, or healthcare providers. Alternatively, more interactive interventions, designed in accordance with various cognitive and behavioural models, seek to modify motivation, confidence, goal setting behaviours, and other psychological constructs in an effort to improve CPAP adherence. Often, a combination of approaches is used (Aloia 2013; Bartlett 2013; Bouloukaki 2014; Hui 2000; Hwang 2017; Lewis 2006; Meurice 2007; Sawyer 2017; Sedkaoui 2015; Shapiro 2017; Smith 2006; Wang 2012). On the technological domain, modifications of delivery of airway pressure, such as the use of automatically titrating CPAP (auto‐CPAP), bi‐level PAP (BPAP) and humidification therapy, claim to decrease side effects in the upper airway due to cold and dry airflow and thus improve the comfort of treatment, but have not yielded convincing benefits in clinical trials to date (Smith 2009).

Why it is important to do this review

Despite the apparent efficacy of CPAP and its therapeutic benefits extending beyond amelioration of OSA symptoms to other functional and potential health outcomes, treatment adherence has been persistently low (Rotenberg 2016). Interventions directed at improving CPAP usage vary in methodology, complexity and effectiveness. Knowing what type of intervention is efficacious and potentially effective in clinical practice would guide clinicians and health authorities in developing services and guidelines aimed at improving treatment adherence. Since the last Cochrane Review, published in 2014 (Wozniak 2014), which assessed educational, supportive and behavioural interventions aimed at improving CPAP usage, a substantial number of new studies have been reported. This review updates the evidence.

Objectives

To assess the effectiveness of interventions that employ educational, supportive, behavioural, or mixed approaches to encourage adults who have been prescribed continuous positive airway pressure (CPAP) to use their devices.

Methods

Criteria for considering studies for this review

Types of studies

Randomised, parallel‐controlled trials of any duration.

Types of participants

Participants were adults of either sex with a diagnosis of obstructive sleep apnoea (OSA) using a recognised sleep diagnostic tool giving an Oxygen Desaturation Index (ODI) of ≥ 5 per hour or an apnoea hypopnoea index (AHI) ≥ 5 per hour. Trials that explicitly recruited patients with central sleep apnoea were not eligible for inclusion.

Types of interventions

Intervention group

Any short‐term or sustained intervention aimed at encouraging uptake, acclimation, improvement or maintenance of continuous positive airway pressure (CPAP) adherence among individuals with a diagnosis of OSA. Examples of modalities that our review intended to capture include educational, supportive, group‐based, mindfulness‐based, cognitive, behavioural, motivational or approaches utilising a combination of these strategies.

Control group

Participants in the control group may receive instruction that would be used by the study centre in question, provided that the equivalent 'background' level of instruction was also offered and delivered to the intervention group. Intervention and control groups must have also either 1) received the same make of CPAP machine and pressure delivery mode (i.e. fixed, auto‐titrating, bi‐level PAP (BPAP), etc.) or 2) receive PAP devices in a randomly distributed manner, such that device make remained independent of group assignment.

Types of outcome measures

Primary outcomes

CPAP device usage (hours/night) as measured by:

microprocessor and monitor that measure pressure at the mask for every minute of each 24‐hour day;
counter output that records the cumulative time that power is turned on for a CPAP machine (this does not provide information on actual time of day and duration of CPAP used during each 24‐hour period);
subjective participant reports of the duration of CPAP use.

Secondary outcomes

The following secondary outcomes were considered:

proportion of participants adherent (≥ 4 hours/night);
sleepiness symptom scores such as the Epworth Sleepiness Scale (ESS);
disease‐specific quality of life scores such as Functional Outcomes of Sleep Questionnaire (FOSQ) or Calgary Sleep apnoea Quality of Life Index (SAQLI) scores;
any standardised depression or anxiety symptom scale measurement;
withdrawals from the study;
oxygen desaturation index (ODI), apnoea hypopnoea index (AHI);
cost‐effectiveness.

Search methods for identification of studies

Electronic searches

We identified studies from the Cochrane Airways Trials Register, which is maintained by the Information Specialist for the Group. The Cochrane Airways Trials Register contains studies identified from several sources.

Monthly searches of the Cochrane Central Register of Controlled Trials (CENTRAL), through the Cochrane Register of Studies Online (crso.cochrane.org)
Weekly searches of MEDLINE Ovid SP 1946 to April 2019
Weekly searches of Embase Ovid SP 1974 to April 2019
Monthly searches of PsycINFO Ovid SP 1967 to April 2019
Monthly searches of CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature) 1937 to April 2019
Monthly searches of AMED EBSCO (Allied and Complementary Medicine) all years to April 2019
Hand searches of the proceedings of major respiratory conferences.

Studies contained in the Trials Register were identified through search strategies based on the scope of Cochrane Airways. Details of these strategies, as well as a list of handsearched conference proceedings are in Appendix 2. See Appendix 3 for search terms used to identify studies for this review.

Searches in the Cochrane Airways Trials Register and additional sources were completed from inception to April 2019, with no restrictions on language or publication type. Review authors attempted to contact authors to locate potential unpublished or in‐progress studies that met the inclusion criteria. When seeking further information of studies represented by trial registries or conference proceedings abstracts, the review authors contacted the trial authors for clarification if 1) the study was deemed to be potentially relevant according to inclusion criteria, 2) if the study appeared to be complete based on the information documented on ClinicalTrials.gov, 3) if no full publication was listed on the trial registry records, 4) and if no full publication was identified via an author/title/element PubMed search.

Searching other resources

We searched Epistemonikos (International database of systematic reviews) all years to April 2019 to identify other relevant systematic reviews, and checked their reference lists. We completed additional handsearching of the bibliographies of identified trials. The 2013‐2018 ATS and the 2013‐2018 European Respiratory Society (ERS) meeting abstracts were also handsearched for the current review update.

Data collection and analysis

Selection of studies

Review authors (KDA and LW) independently reviewed the titles, abstracts and citations identified through electronic searching to assess potential relevance for full review. Conflicting decisions on inclusion were resolved through discussion and consensus. Records eligible for full‐text review were scrutinised independently (KDA and LW) for inclusion based on a priori criteria for population, study design, intervention and outcome. Agreement was measured by simple agreement and conflicting decisions on study inclusion were resolved through discussion and consensus (KDA, LW, DRW, IS). See Figure 1 Study Flow Diagram. Reasons for study exclusion at the full‐text review stage were agreed upon by review authors (KDA, LW, DRW, IS) and recorded in the Characteristics of excluded studies table. For included studies, descriptive information for studies and study populations is presented in tabular form (Table 5; Table 6; Table 7;Table 8; Table 9; Table 10; Table 11).

1. Number screened, entered and completed.

Study	N Screened	Entered	Completed	% Screened	% Entered
Aloia 2001	NA	12	12	NA	100
Aloia 2013	339	227	183	54	81
Bakker 2016	479 (only 2 of 4 treatment arms included in this review)	83	78	16	94
Bartlett 2013	294	206	177	60	86
Basoglu 2011	246	133	133	54	100
Bouloukaki 2014	5100	3100	2836	56	91
Chen 2015	85	80	80	94	100
Chervin 1997	NA (75% of those approached agreed to participate)	33	33	NA	100
Dantas 2015	61	41	40	66	98
DeMolles 2004	NA	30	30	NA	100
Diaferia 2017	NA	49	49	NA	100
Falcone 2014	533	206	161	30	78
Fox 2012	NA	75	54	NA	72
Hoet 2017	127	46	37	29	80
Hoy 1999	NA	80	80	NA	100
Hui 2000	NA	108	97	NA	90
Hwang 2017	1873	1455	1236	66	85
Lai 2014	212	100	98	46	98
Lewis 2006	74	72	58	78	81
Mendelson 2014	107	107	82	77	76
Meurice 2007	133	112	112	84	100
Munafo 2016	140	140	122	87	87
Olsen 2012	132	106	94	71	89
Parthasarathy 2013	49	39	37	76	95
Pengo 2018	NA	112	85	NA	76
Pepin 2019	NA	306	239	NA	78
Richards 2007	109	100	96	88	96
Roecklein 2010	NA	30	28	NA	93
Sarac 2017	490	115	115	23	100
Sawyer 2017	431	118	103	24	87
Scala 2012	NA	28	28	NA	100
Sedkaoui 2015	391	379	377	96	99
Shapiro 2017	NA	66	65	NA	98
Smith 2006	NA	19	19	NA	100
Smith 2009	NA	97	73	NA	75
Soares‐Pires 2013	NA	202	146	NA	72
Sparrow 2010	423	250	222	52	89
Stepnowsky 2007	91	45	40	44	89
Stepnowsky 2013	NA	241	240	NA	99
Turino 2017	NA	100	100	NA	100
Wang 2012	NA	152	130	NA	86

Variable	Behavioural (BEH)	Educational (EDU)	Supportive (SUP)	Mixed (MIX)
N (total randomised)	989	1878	1962	5041
Age in years (Mean, SD)	56.44 (5.76)	52.73 (4.68)	53.94 (4.88)	52.55 (5.46)
BMI (Mean, SD)	32.31 (2.90)	34.19 (3.51)	33.19 (2.02)	33.73 (2.80)
Sex (% female)*	34.38	29.98	24.68	32.44
AHI (Mean, SD)	38.08 (9.04)	39.72 (12.25)	41.11 (10.52)	38.82 (10.62)
ESS (Mean, SD)	12.80 (4.02)	11.27 (1.29)	10.47 (1.50)	12.53 (1.92)

Intervention Details	Behavioural (BEH), (median, IQR)	Educational (EDU), (median, IQR)	Supportive (SUP), (median, IQR)	Mixed (MIX), (median, IQR)
Study duration (weeks)	12 (12‐52)	12 (6‐26)	12 (12‐16)	14 (12‐52)
Intervention duration (weeks)	4 (2‐12)	0 (0‐4.5)*	12 (9‐13)	12 (10‐25)
# of Intervention episodes	3 (3‐14)	2 (1‐6)	NR (MOST)	7 (5‐10)
Contact time (minutes)	90 (80‐240)	21 (11‐105)	NR	75 (33‐143)

Study	Studies employing Educational Intervention		Control	Study duration (weeks)
Study	Increased support and reinforcement components (if applicable)	Increased educational components	Control	Study duration (weeks)
Aloia 2013		2 x 45‐minute education sessions regarding pathophysiology of apnoea, medical and behavioral consequences, and the benefits of treatment; presented in standardised formats, with no tailoring to participant readiness, 1 booster call from sleep nurse	Usual care	52
Basoglu 2011		One 10‐minute educational video session on OSA and CPAP	Usual care	24
Chervin 1997		Written information on OSA and CPAP	Usual care	8
Falcone 2014		Two consecutive PSG videos on the computer screen: the first recorded during a standard diagnostic overnight polysomnography, and the second during a full‐night polysomnography with nasal CPAP	Usual care	52
Hwang 2017		Education about OSA pathophysiology , health‐related risks, impact on daytime vigilance, introduction to CPAP therapy	Usual care	12
Pengo 2018		Positively or negatively framed messages in addition to CPAP. Patients were phoned weekly and read framed messages (≤ 6 phone calls per patient).	Usual care	6
Richards 2007		Slide presentation and written information on OSA and CPAP and 2 x 1‐hour CBT sessions	Usual care	4
Roecklein 2010		Personalised feedback report, including detailed information OSA and its associated risk and barriers to CPAP use and attitudes to change	Usual care	12
Sarac 2017		1 x 20‐minute educational session by a sleep medicine physician, including: viewing his/her own PSG chart on morning post PAP‐titration, comparing PSG from diagnostic and CPAP titration studies with explanations that emphasized obstructive events and oxygen desaturations, and the disappearance of those signs on PAP treatment.	Usual care	24
Soares‐Pires 2013		1 x 1‐hour educational session with information regarding OSA, its symptoms and risks, APAP treatment, the importance of good adherence, and different machine interfaces.	Usual care	24
Wang 2012	Two additional nights of CPAP titration	4‐hour group education session, written information, video CD	Usual care	12

Study	Studies employing Supportive Intervention		Control	Study duration (weeks)
Study	Increased support and reinforcement components	Increased educational components (if applicable)	Control	Study duration (weeks)
Chervin 1997	Weekly telephone calls to monitor progress and troubleshoot		Usual care	8
DeMolles 2004	Computer‐based telecommunication system allowing for monitoring and reinforcing compliance	Education via computer‐based telecommunication system	Usual care	8
Fox 2012	Telecomunication system for daily monitoring of CPAP usage, timely detection and troubleshooting of problems		Usual care	12
Hoet 2017	Telemonitoring device forair leaks, residual AHI > 10/h, or CPAP use less than 3 hours for 3 days		Usual care	12
Hoy 1999	2 additional titration nights in hospital, 4 additional home visits by sleep nurses	Initial education at home with partner	Usual care	24
Hwang 2017	Automatic processing of device data. Where CPAP usage thresholds met, automated message encouraged participant to improve use/positive reinforcement		Usual care	12
Mendelson 2014	Participants equipped with smartphone for uploading BP, CPAP adherence, sleepiness, and QoL data. They received daily pictograms containing health‐related messages		Usualo care	16
Munafo 2016	Web‐based app used to monitor adherence and automatically message patients and providers when pre‐set conditions met		Usual care	12
Parthasarathy 2013	2 individual sessions and 8 telephone conversations with trained peer CPAP users providing support and sharing their positive experience with CPAP		Usual care	12
Pepin 2019	BP and physical activity recorded by multimodal telemonitoring device and electronic questionnaires completed by patients. Automatic algorithms constructed for prompt adjustment of CPAP treatment.		Usual care	24
Stepnowsky 2007	Daily wireless telemonitoring of compliance and treatment efficacy and acting on the data via prespecified clinical pathways		Usual care	8
Stepnowsky 2013	Telemonitoring device collecting daily CPAP adherence viewable by both patient and provider. Troubleshooting and feedback provided when necessary		Usual care	16
Turino 2017	Daily CPAP adherence, CPAP pressures, mask leak and residual respiratory events transmitted into a web database. Case by case guidance provided by provider when signalled by automatic alarm in the web database		Usual care	12

Study	Studies employing Behavioural Intervention			Control	Study duration (weeks)
Study	Increased support and reinforcement components (if applicable)	Increased educational components (if applicable)	Behavioural therapy	Control	Study duration (weeks)
Aloia 2001		Elements of education on consequences of OSA and efficacy of CPAP	2 x 45‐minute sessions of CBT interventions	2 x 45‐minute sessions on sleep architecture and sleep clinic	12
Aloia 2013			2 x 45‐minute sessions of MET, one booster phone call	Usual care	52
Bakker 2016			Eight ‐ hour in person MET session	Usual care	52
Dantas 2015			1 x 10‐minute MET session	Usual care	8
Diaferia 2017			Thirty‐six myofunctional therapy sessions	Usual care	36
Lai 2014			One brief MET session (video and patient interview), followed by a follow‐up phone call	Usual Care	12
Olsen 2012		45‐Minute individual education session	Three 30‐minute sessions of MET	45‐Minute educational session + usual care	52
Scala 2012			3 interactive sessions, video with discussion, focus group and role play, respectively 1, 2 and 3 months after receiving the CPAP device.	Usual Care	52
Smith 2009			Audiotaped music and softly spoken directions on relaxation techniques and habit‐promoting instructions for using CPAP nightly. Information packet,including CPAP use reminder placard, handouts on benefits of CPAP adherence and health consequences of poor compliance, 4‐week diary for recording experience with CPAP	Audiotaped music with softly spoken information on vitamins, informational packet on vitamins and health.	12
Sparrow 2010			Automated telephone‐linked communication system designed around the concept of Motivational Interviewing, which allowed one to assess and enhance CPAP compliance	Education on unrelated health topics via automated telephone‐linked communication system	52
Wang 2012	One night of CPAP titration in the hospital		12 x 40‐minute group PMR practice sessions over 12 weeks, one per week. Self‐practice of PMR before each CPAP treatment. Brochure and CD with a guide for PMR practice at home.	Usual care	12

Study	Studies employing Mixed Intervention			Control	Study duration (weeks)
Study	Increased support and reinforcement components	Increased educational components	Behavioural therapy	Control	Study duration (weeks)
Bartlett 2013		1 x 30 minute group education session	1 x 35‐minute intervention based on SCT , including perceived self‐efficacy, outcome expectations, and social support	Usual care + a 30‐minute group education session and social period matching the duration of the intervention	24
Bouloukaki 2014	Two phone calls from study nurse to discuss CPAP use, 1 month of sleep diary review by sleep specialist, and 6 in‐person follow‐ups involving patient's family or spouse	1 x 15 minute video education session covering OSA topics, followed by 10‐minute lecture to reinforce key topics		Usual care	104
Chen 2015	Personalised guidance from a study nurse, home visits from a nurse discussing lifestyle management, mental well‐being, and 1 x 30‐minute consultation with a sleep physician	1 x pre‐treatment OSA educational video		Usual care	52
Hui 2000	2 additional early reviews by sleep physician and frequent telephone calls by sleep nurses	Videotape and additional education session		Usual care	12
Hwang 2017	Intervention based on automatic processing of device data. If CPAP usage thresholds were met, a message was automatically sent to the patient providing encouragement to improve use or positively reinforcing successful adherence.	Education about pathophysiology of OSA, health‐related risks, impact on daytime vigilance, introduction to CPAP therapy		Usual care	12
Lewis 2006	1 additional early review by sleep physician and 1 early telephone interview with sleep nurse	Educational video		Usual care	52
Meurice 2007	4 additional home visits in the first 3 months by sleep practitioner for problem solving	Written information and detailed explanation by the prescriber, additional education during home visits		Written information and detailed explanation by the prescriber + usual care	52
Sawyer 2017		Educational DVD on sleep apnoea and PSG review	4 x 30‐60 minute sessions addressing cognitive perceptions of the OSA and CPAP, outcome expectancies with PAP treatment, and PAP treatment self‐efficacy, all domains of SCT	Usual care and an informational pamphlet about OSA, diagnosis and PAP prescription provided by sleep centre	12
Sedkaoui 2015	5 x standardised support sessions through telephone‐based counselling	Education addressing knowledge about OSA, disadvantage or obstacles to CPAP		Usual care	16
Shapiro 2017	2 x support calls with study investigator to promote the use of CPAP	1 x educational session using an airway model along with a video and worksheet on OSA, and a report card to document OSA severity, CPAP setting and use and participant self‐evaluation		Usual care	4
Smith 2006	Home video‐link sessions delivered by nurse, who guided correct CPAP use and provided problem solving	Nurse provided education on CPAP and OSA		Home video‐link sessions similar in form to intervention but directed activities in neutral health topics (vitamin intake)	12
Wang 2012	Three nights of CPAP titration in the hospital	4‐hout group education session, written information, video CD	12 x 40 minute group PMR practice sessions over 12 weeks	Usual care	12

Educational interventions + CPAP compared to usual care + CPAP in adults with obstructive sleep apnoea
Patient or population: adults with obstructive sleep apnoea  Setting: community  Intervention: educational interventions + CPAP  Comparison: usual care + CPAP
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
Outcomes	Risk with usual care + CPAP	Risk with Educational interventions + CPAP	Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
1.1 CPAP device usage (hours/night)	The mean CPAP device usage ranged from 1.97 to 5.1 hours/night	MD 0.85 hours/night higher  (0.32 higher to 1.39 higher)	‐	1128  (10 RCTs)	⊕⊝⊝⊝  VERY LOW ^{1 2 3 4}
1.2 CPAP device usage (hours/night), sensitivity analysis: adherence in control group < four hours/night	The mean CPAP device usage , sensitivity analysis: adherence in control group < four hours/night ranged from 1.97 to 3.8 hours/night	MD 0.85 hours/night higher  (0.06 higher to 1.64 higher)	‐	698  (6 RCTs)	⊕⊝⊝⊝  VERY LOW ^{3 4 5 6}
1.3 N deemed adherent (≥ four hours/night)	558 per 1,000	765 per 1,000  (654 to 849)	OR 2.58  (1.50 to 4.44)	1019  (7 RCTs)	⊕⊝⊝⊝  VERY LOW ^{3 4 7 8}
1.4 Withdrawal ‐ NO META‐ANALYSIS PERFORMED			‐	1745  (9 studies)	‐
1.5 ESS ‐ Comparison of values at endpoint‐ NO META‐ANALYSIS PERFORMED	‐		‐	355  (3 studies)	‐
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).    CI: Confidence interval; CPAP: Continuous positive airways pressure;ESS: Epworth Sleepiness Scale; GRADE: Grades of Recommendation, Assessment, Development and Evaluation; MD: mean difference; OR: Odds ratio; RCT: randomised controlled trial.
GRADE Working Group grades of evidence  High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.  Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.  Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect.  Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

Increased practical support and encouragement during follow‐up + CPAP compared to usual care + CPAP in adults with obstructive sleep apnoea
Patient or population: adults with obstructive sleep apnoea  Setting: community  Intervention: increased practical support and encouragement during follow‐up + CPAP  Comparison: usual care + CPAP
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
Outcomes	Risk with usual care + CPAP	Risk with Increased practical support and encouragement during follow‐up + CPAP	Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
2.1 CPAP device usage (hours/night)	The mean CPAP device usage ranged from 1.75 to 4.9 hours/night	MD 0.70 hours/night higher  (0.36 higher to 1.05 higher)	‐	1426  (13 RCTs)	⊕⊕⊕⊝  MODERATE ^{1 2 3 4}
2.2 CPAP device usage, sensitivity analysis: adherence in control group < four hours/night	The mean CPAP device usage, sensitivity analysis: adherence in control group < four hours/night ranged from 1.75 to 3.8 hours/night	MD 0.91 hours/night higher  (0.57 higher to 1.25 higher)	‐	735  (7 RCTs)	⊕⊕⊕⊕  HIGH ^{3 4 5}
2.3 N deemed adherent (≥ four hours/night)	601 per 1,000	717 per 1,000  (619 to 797)	OR 1.68  (1.08 to 2.60)	376  (2 RCTs)	⊕⊕⊝⊝  LOW ^{3 6 7}
2.4 Withdrawals	136 per 1,000	167 per 1,000  (133 to 208)	OR 1.27  (0.97 to 1.66)	1702  (11 RCTs)	⊕⊕⊝⊝  LOW ^{3 8}
2.5.2 ESS: Comparison Endpoint or Change from Baseline Values ‐ ESS: Change from Baseline	The mean ESS ‐ Comparison Endpoint or Change from Baseline Values ‐ ESS: Change from Baseline ranged from ‐0.7 to ‐5.1	MD 0.32 lower  (1.19 lower to 0.56 higher)	‐	470  (5 RCTs)	⊕⊕⊝⊝  LOW ^{3 7 9}
2.7 Quality of lIfe: Comparison of Change from Baseline Values	The mean Quality of lIfe: Comparison of Change from Baseline Values was 0	SMD 0.22 higher  (0.01 lower to 0.45 higher)	‐	294  (3 RCTs)	⊕⊝⊝⊝  VERY LOW ^{3 9 10 11}
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).    CPAP: Continuous positive airways pressure; CI: Confidence interval; ESS: Epworth Sleepiness Scale; FOSQ: Functional Outcomes of Sleep Questionnaire; GRADE: Grades of Recommendation, Assessment, Development and Evaluation; MD: mean difference; OR: Odds ratio; RCT: randomised controlled trial; SMD: standardised mean difference.
GRADE Working Group grades of evidence  High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.  Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.  Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect.  Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

Behavioural therapy + CPAP compared to control + CPAP in adults with obstructive sleep apnoea
Patient or population: adults with obstructive sleep apnoea  Setting: community  Intervention: behavioural therapy + CPAP  Comparison: control + CPAP
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
Outcomes	Risk with control + CPAP	Risk with Behavioural therapy + CPAP	Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
3.1 CPAP Device Usage (hours/night)	The mean CPAP Device Usage ranged from 1.48 to 5.1 hours/night	MD 1.31 hours/night higher  (0.95 higher to 1.66 higher)	‐	578  (8 RCTs)	⊕⊕⊕⊕  HIGH ^{1 2 3}
3.2 CPAP Device Usage, sensitivity analysis: adherence in control group < four hours/night	The mean CPAP Device Usage, sensitivity analysis: adherence in control group < four hours/night ranged from 1.48 to 3.65 hours/night	MD 1.32 hours/night higher  (0.93 higher to 1.72 higher)	‐	525  (6 RCTs)	⊕⊕⊕⊝  MODERATE ^{1 2 4 5}
3.3 N deemed adherent (≥ four hours/night)	Study population		OR 1.70  (1.20 to 2.41)	549  (6 RCTs)	⊕⊕⊕⊕  HIGH ^{1 6 7}
3.3 N deemed adherent (≥ four hours/night)	371 per 1,000	501 per 1,000  (414 to 587)	OR 1.70  (1.20 to 2.41)	549  (6 RCTs)	⊕⊕⊕⊕  HIGH ^{1 6 7}
3.4 Withdrawal	146 per 1,000	101 per 1,000  (70 to 143)	OR 0.66  (0.44 to 0.98)	939  (10 RCTs)	⊕⊕⊕⊕  HIGH
3.5 ESS (Endpoint scores)	The mean ESS (Endpoint scores) ranged from 7.1 to 12.5	MD 2.42 lower  (4.27 lower to 0.57 lower)	‐	271  (5 RCTs)	⊕⊕⊝⊝  LOW ^{1 8 9}
3.6 AHI on treatment ‐ Endpoint	The mean AHI at endpoint ranged from 3.7 to 4.3 events/hour	MD 0.95 events/hour lower  (2.25 lower to 0.34 higher)	‐	89  (2 RCTs)	⊕⊝⊝⊝  VERY LOW ^{1 10 11}
3.7 Quality of Life ‐ Comparison of Values at Endpoint	The mean Quality of Life ‐ Comparison of Values at Endpoint was 0	SMD 0  (0.26 lower to 0.26 higher)	‐	228  (3 RCTs)	⊕⊕⊕⊝  MODERATE ^{1 8}
3.7.1 Quality of Life ‐ Comparison of Values at Endpoint ‐ QoL: FOSQ ‐ Endpoint	The mean Quality of Life ‐ Comparison of Values at Endpoint ‐ QoL: FOSQ ‐ Endpoint was 0	SMD 0.01 higher  (0.26 lower to 0.29 higher)	‐	200  (2 RCTs)	‐
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).    AHI: apnoea hypopnoea index; CI: Confidence interval; CPAP: Continuous positive airways pressure;ESS: Epworth sleepiness scale; FOSQ: Functional Outcomes of Sleep Questionnaire; GRADE: Grades of Recommendation, Assessment, Development and Evaluation; MD: mean difference; OR: Odds ratio; RCT: randomised controlled trial; SMD: standardised mean difference.
GRADE Working Group grades of evidence  High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.  Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.  Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect.  Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

Mixed (SUP/EDU/BEH) Intervention + CPAP compared to Usual Care + CPAP in adults with obstructive sleep apnoea
Patient or population: adults with obstructive sleep apnoea  Setting: community  Intervention: mixed (SUP/EDU/BEH) Intervention + CPAP  Comparison: usual Care + CPAP
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
Outcomes	Risk with Usual Care + CPAP	Risk with Mixed (SUP/EDU/BEH) Intervention + CPAP	Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
4.1 CPAP Device Usage (hours/night)	The mean CPAP Device Usage ranged from 2.6 to 5.5 hours/night	MD 0.82 hours/night higher  (0.20 higher to 1.43 higher)	‐	4509  (11 RCTs)	⊕⊝⊝⊝  VERY LOW ^{1 2 3 4}
4.2 CPAP Device Usage, sensitivity analysis: adherence in control group < four hours/night	The mean CPAP Device Usage, sensitivity analysis: adherence in control group < four hours/night ranged from 2.6 to 3.8 hours/night	MD 1.77 hours/night higher  (0.21 higher to 3.34 higher)	‐	343  (2 RCTs)	⊕⊝⊝⊝  VERY LOW ^{4 5 6}
4.3 N deemed adherent (≥ four hours/night)	741 per 1,000	830 per 1,000  (755 to 886)	OR 1.71  (1.08 to 2.72)	4015  (9 RCTs)	⊕⊝⊝⊝  VERY LOW ^{4 7 8}
4.4 Withdrawal	129 per 1,000	83 per 1,000  (40 to 161)	OR 0.61  (0.28 to 1.30)	4956  (11 RCTs)	⊕⊝⊝⊝  VERY LOW ^{9 10 11}
4.5 Quality of LIfe: Comparison of Change from Baseline Values	The mean Quality of LIfe: Comparison of Change from Baseline Values was 0	SMD 0.45 higher  (0.12 higher to 0.78 higher)	‐	3012  (2 RCTs)	⊕⊕⊝⊝  LOW ^{12 13 14}
4.7 Anxiety Symptom Rating ‐ Comparison of Values at Endpoint	The mean Anxiety Symptom Rating ‐ Comparison of Values at Endpoint was 0	SMD 0.19 lower  (0.47 lower to 0.09 higher)	‐	333  (3 RCTs)	⊕⊝⊝⊝  VERY LOW ^{12 15 16}
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).    CI: Confidence interval; CPAP: Continuous positive airways pressure; GRADE: Grades of Recommendation, Assessment, Development and Evaluation; MD: mean difference; OR: Odds ratio; RCT: randomised controlled trial; SMD: standardised mean difference.
GRADE Working Group grades of evidence  High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.  Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.  Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect.  Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

Class	Full class effect estimate, MD (95% CI)	Sensitivity: excluding high RoB studies (MD, 95%CI)
Behavioural	1.31 (0.95 to 1.66) I² = 0% Analysis 3.1	1.05 (0.57 to 1.53)¹ I² = 0% Analysis 5.6
Educational	0.85 (0.32 to 1.39) I² = 68% Analysis 1.1	0.98 (0.07 to 1.89)² I² = 86% Analysis 5.4
Supportive	0.70 (0.36 to 1.05) I² = 42% (Analysis 2.1)	0.75 (0.42 to 1.09)³ I² = 34% Analysis 5.5
Mixed	0.82 (0.20 to 1.43) I² = 92% Analysis 4.1	NA

Class	Full class effect estimate, MD (95%CI)	Intervention duration, MD (95%CI)	Contact episodes: 1 vs. > 1, MD (95%CI)	Total contact time: > vs. ≤ 60 minutes, MD (95%CI)
Behavioral	1.31 (0.95 to1.66) I² = 0% Analysis 3.1	> 4 weeks¹: 1.21 (0.60 to 1.82) I² = 0% ≤ 4 weeks²: 1.38 (0.80 to 1.95) I² = 38% Test for subgroup differences: Chi² = 0.15, df = 1 (P = 0.70), I² = 0% Analysis 6.7	> 1 episode³: 1.35 (0.94 to 1.77) I² = 9% 1 episode⁴: 1.10 (0.26 to1.94) I² = 0% Test for subgroup differences: Chi² = 0.28, df = 1 (P = 0.60), I² = 0% Analysis 6.8	> 60 minutes⁵: 1.15 (0.71 to 1.60); I² = 0% ≤ 60 minutes⁶: 1.56 (0.68 to 2.44); I² = 57% Test for subgroup differences: Chi² = 0.64, df = 1 (P = 0.42), I² = 0% Analysis 6.9
Educational	0.85 (0.32 to 1.39) I² = 68% Analysis 1.1	> 4 weeks⁷: 0.33 (‐0.10 to 0.77); I² = 0% ≤ 4 weeks⁸: 1.20 (0.39 to2.01); 12=75% Test for subgroup differences: Chi² = 3.36, df = 1 (P = 0.07), I² = 70.2% Analysis 6.1	> 1 episode⁹: 1.20 (0.41 to2.00); I² = 70% 1 episode¹⁰: 0.40 (‐0.06 to 0.86); I² = 0% Test for subgroup differences: Chi² = 2.96, df = 1 (P = 0.09), I² = 66.2% Analysis 6.2	> 60 minutes¹¹: 1.46 (0.22 to 2.71); I² = 82% ≤ 60 minutes¹²: 0.61 (0.00 to 1.22); I² = 37% Test for subgroup differences: Chi² = 1.47, df = 1 (P = 0.23), I² = 31.9% Analysis 6.3
Supportive	0.70 (0.36 to 1.05) I² = 42% (Analysis 2.1)	> 12 weeks¹³: 0.49 (‐0.53 to 1.51); I² = 77% ≤ 12 weeks¹⁴: 0.72 (0.43 to 1.01); I² = 0% Test for subgroup differences: Chi² = 0.17, df = 1 (P = 0.68), I² = 0% Analysis 6.4	NA	NA
Mixed	0.82 (0.20 to 1.43) I² = 92% Analysis 4.1	> 4 weeks¹⁵: 1.22 (0.60 to 1.83); I² = 91% ≤ 4 weeks¹⁶: ‐0.31 (‐0.83 to 0.21); I² = 0% Test for subgroup differences: Chi² = 13.79, df = 1 (P = 0.0002), I² = 92.7% Analysis 6.10	> 1 episode¹⁷: 0.98 (0.32 to 1.62); I² = 92% 1 episode¹⁸: ‐0.60 (‐1.33 to 0.13); I² = 93% Test for subgroup differences: Chi² = 9.94, df = 1 (P = 0.002), I² = 89.9% Analysis 6.11	> 60 minutes¹⁹: 1.45 (0.73 to 2.16); I² = 91% ≤ 60 minutes²⁰: ‐0.15 (‐0.56 to 0.27); I² = 0% Test for subgroup differences: Chi² = 14.14, df = 1 (P = 0.0002), I² = 92.9% Analysis 6.12

Class	All supportive interventions, MD (95%CI)	Intervention involved human support, MD (95%CI)	Intervention involved scheduled human support, MD (95%CI)
Supportive	0.70 (0.35 to 1.05) I² = 42% (Analysis 2.1)	Any human support¹: 0.84 (0.52 to 1.17) I² = 10% Automated support only²: 0.26 (‐0.51 to 1.04) I² = 64% Test for subgroup differences: Chi² = 1.85, df = 1 (P = 0.17), I² = 46.0% Analysis 6.5	Pre‐scheduled human support³: 1.43 (0.61 to 2.24) I² = 0% No Scheduled human support⁴: 0.58 (0.33 to 0.83) I² = 45% Test for subgroup differences: Chi² = 3.82, df = 1 (P = 0.05), I² = 73.8% Analysis 6.6

Class	Updated Review (Askland 2019) Classification Decision, MD (95%CI)	Sensitivity: Original (Wozniak 2014) Classification Decision, MD (95%CI)
Behavioral	1.31 (0.95 to1.66) I² = 0% Analysis 3.1	1.47 (1.12 to 1.83) I² = 48% Analysis 5.3
Educational	0.85 (0.32 to 1.39) I² = 68% Analysis 1.1	0.48 (0.21 to 0.76) I² = 0% Analysis 5.1
Supportive	0.70 (0.36 to 1.05) I² = 42% (Analysis 2.1)	0.58 (0.36 to 0.81) I² = 45% Analysis 5.2

Class	Full Class Effect Estimates	Exclude endpoints NOT 3 months
Behavioral	1.31 (0.95 to 1.66) I² = 0% Analysis 3.1	1.38 (0.97 to 1.79)
Educational	0.85 (0.32 to 1.39) I² = 68% Analysis 1.1	0.63 (0.26 to 1.00)
Supportive	0.70 (0.36 to 1.05) I² = 42% (Analysis 2.1)	0.67 (0.29 to 1.04)
Mixed	0.82 (0.20 to 1.43) I² = 92% Analysis 4.1	1.09 (0.21 to 1.97)

Date	Event	Description
29 April 2019	New citation required and conclusions have changed	Review updated with 11 new studies. The background was redrafted and updated. 'Risk of bias 2' assessment of the primary outcome for all studies. Outcomes and subgroup analyses updated.
29 April 2019	New search has been performed	New literature search run

Date	Event	Description
17 January 2013	New citation required and conclusions have changed	13 new studies added. Changes made in review conclusions in relation to short course interventions. Summary of findings table added
17 January 2013	New search has been performed	Literature searches rerun
10 March 2009	Amended	Spelling correction
5 September 2008	Amended	Converted to new review format.
12 October 2006	New citation required and conclusions have changed	Substantive amendment

Database	Dates searched	Frequency of search
CENTRAL (via the Cochrane Register of Studies (CRS))	From inception	Monthly
MEDLINE (Ovid SP) ALL	1946 onwards	Weekly
Embase (Ovid SP)	1974 onwards	Weekly
PsycINFO (Ovid SP)	1967 onwards	Monthly
CINAHL (EBSCO)	1937 onwards	Monthly
AMED (EBSCO)	From inception	Monthly

Conference	Years searched
American Academy of Allergy, Asthma and Immunology (AAAAI)	2001 onwards
American Thoracic Society (ATS)	2001 onwards
Asia Pacific Society of Respirology (APSR)	2004 onwards
British Thoracic Society Winter Meeting (BTS)	2000 onwards
Chest Meeting	2003 onwards
European Respiratory Society (ERS)	1992, 1994, 2000 onwards
International Primary Care Respiratory Group Congress (IMyhill 201RG)	2002 onwards
Thoracic Society of Australia and New Zealand (TSANZ)	1999 onwards

Strategy	Details
#1	SLP:MISC1
#2	MeSH DESCRIPTOR Sleep Apnea, Obstructive
#3	sleep near3 (apnoea* or apnoea*)
#4	(hypopnoea* or hypopnoea*)
#5	(OSA OR SHS OR OSAHS:TI,AB)
#6	#1 OR #2 OR #3 OR #4 OR #5
#7	MESH DESCRIPTOR Continuous Positive Airway Pressure
#8	CPAP or Auto‐CPAP or APAP or NCPAP
#9	(continuous* OR nasal* OR inspiratory*) NEAR "positive airway"
#10	(positive* or expiratory) NEAR (pressure)
#11	(PEEP or IPB or IPPB):ti,ab
#12	#7 OR #8 OR #9 OR #10 OR #11
#13	#12 AND #5
#14	MESH DESCRIPTOR Education
#15	MESH DESCRIPTOR Patient Education as Topic
#16	MESH DESCRIPTOR Health Promotion EXPLODE ALL
#17	MESH DESCRIPTOR Self‐Management
#18	MESH DESCRIPTOR Self care
#19	educat* or train* or instruct*
#20	self‐manage* or self manage*
#21	Self‐care* or self care*
#22	support*:ti,ab
#23	MESH DESCRIPTOR Behavior Therapy EXPLODE ALL
#24	(behavior* or behaviour*):ti,ab,kw
#25	psychotherap*:ti,ab,kw
#26	MESH DESCRIPTOR Motivational Interviewing
#27	MESH DESCRIPTOR Motivation EXPLODE ALL
#28	motivat*:ti,ab,kw
#29	cognitive*:ti,ab,kw
#30	self‐efficacy:ti,ab,kw
#31	MeSH DESCRIPTOR Patient Compliance Explode All
#32	MeSH DESCRIPTOR Patient Acceptance of Health Care Explode All
#33	adhere* or nonadhere* or non‐adhere*
#34	accept* or comply or compliance or reinforce*
#35	#14 OR #15 OR #16 OR #17 OR #18 OR #19 OR #20 OR #21 OR #22 OR #23 OR #24 OR #25 OR #26 OR #27 OR #28 OR #29 OR #30 OR #31 OR #32 OR #33 OR #34
#36	#35 AND #13
#37	INREGISTER
#38	#36 AND #37

Field	Search Term
Condition	Sleep Apnoea
Intervention	CPAP OR continuous positive airway pressure
Other search terms	adherence OR compliance OR comply
Study type	Interventional Studies

Database	Years searched	Date of search	References before de‐duplication	References after de‐duplication	Comments
Airways Register (via the CRS)	all	2018/07/11	861	861
Clinicaltrial.gov	all	2018/07/11	162	147
WHO trials portal	all	2018/07/11	122	94
Epistemonikos	all	2018/08/29	32	‐	Search for related systematic reviews
Total			1177	1102	1074; 28 included refs; 4 awaiting classification

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 CPAP Device Usage (hours/night)	10	1128	Mean Difference (IV, Random, 95% CI)	0.85 [0.32, 1.39]
2 Machine usage, sensitivity analysis: adherence in control group < four hours/night	6	698	Mean Difference (IV, Random, 95% CI)	0.85 [0.06, 1.64]
3 N deemed adherent (≥ four hours/night)	7	1019	Odds Ratio (M‐H, Random, 95% CI)	2.58 [1.50, 4.44]
4 Withdrawal	9		Odds Ratio (M‐H, Random, 95% CI)	Totals not selected
5 Epworth Sleepiness Scale ‐ Comparison of Values at Endpoint	3		Mean Difference (IV, Random, 95% CI)	Totals not selected

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 CPAP Device Usage (hours/night)	13	1426	Mean Difference (IV, Random, 95% CI)	0.70 [0.36, 1.05]
2 Machine usage, sensitivity analysis: adherence in control group < four hours/night	7	735	Mean Difference (IV, Fixed, 95% CI)	0.91 [0.57, 1.25]
3 N deemed adherent (≥ four hours/night)	2	376	Odds Ratio (M‐H, Fixed, 95% CI)	1.68 [1.08, 2.60]
4 Withdrawals	11	1702	Odds Ratio (M‐H, Fixed, 95% CI)	1.27 [0.97, 1.66]
5 Epworth Sleepiness Scale ‐ Comparison Endpoint or Change from Baseline Values	9		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
5.1 ESS: Endpoint Scores	6	700	Mean Difference (IV, Fixed, 95% CI)	0.03 [‐0.59, 0.64]
5.2 ESS: Change from Baseline	5	470	Mean Difference (IV, Fixed, 95% CI)	‐0.32 [‐1.19, 0.56]
6 Quality of Life: Comparison of Values at Endpoint	7	683	Std. Mean Difference (IV, Fixed, 95% CI)	0.16 [0.01, 0.31]
6.1 QoL: FOSQ ‐ Endpoint	3	109	Std. Mean Difference (IV, Fixed, 95% CI)	0.15 [‐0.23, 0.53]
6.2 QoL: SAQLI ‐ Endpoint	1	240	Std. Mean Difference (IV, Fixed, 95% CI)	0.22 [‐0.04, 0.47]
6.3 QoL: SF‐36 (PH) ‐ Endpoint	3	334	Std. Mean Difference (IV, Fixed, 95% CI)	0.13 [‐0.09, 0.34]
7 Quality of LIfe: Comparison of Change from Baseline Values	3	294	Std. Mean Difference (IV, Fixed, 95% CI)	0.22 [‐0.01, 0.45]
7.1 QoL: FOSQ ‐ Change from Baseline	1	39	Std. Mean Difference (IV, Fixed, 95% CI)	0.24 [‐0.40, 0.87]
7.2 QoL: SF‐36 (PH) ‐ Change from Baseline	1	82	Std. Mean Difference (IV, Fixed, 95% CI)	0.04 [‐0.40, 0.47]
7.3 QoL: FOSQ‐10 ‐ Change from Baseline	1	173	Std. Mean Difference (IV, Fixed, 95% CI)	0.30 [0.00, 0.60]
8 Anxiety Symptom Rating (HADS‐A) ‐ Comparison of Values at Endpoint	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
9 Machine usage, sensitivity analysis: excluding study with opposite direction of effect (authors suggest negative effect of intervention)	12	1319	Mean Difference (IV, Random, 95% CI)	0.74 [0.49, 0.98]
10 AHI on treatment ‐ Comparison of Values at Endpoint	2		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
11 Depression Symptom Rating (HADS‐D, CES‐D) ‐ Comparison of Values at Endpoint	3		Std. Mean Difference (IV, Fixed, 95% CI)	Totals not selected
11.1 HADS‐Depression	1		Std. Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
11.2 CES‐D	2		Std. Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
12 Cost‐Effectiveness	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
13 Machine usage, sensitivity analysis: excluding participants aware of machine usage	2		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

PERMALINK

Educational, supportive and behavioural interventions to improve usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea

Kathleen Askland

Lauren Wright

Dariusz R Wozniak

Talia Emmanuel

Jessica Caston

Ian Smith

Abstract

Background

Objectives

Search methods

Selection criteria

Data collection and analysis

Main results

Authors' conclusions

Plain language summary

Summary of findings

Background

Description of the condition

Description of the intervention

How the intervention might work

Why it is important to do this review

Objectives

Methods

Criteria for considering studies for this review

Types of studies

Types of participants

Types of interventions

Intervention group

Control group

Types of outcome measures

Primary outcomes

Secondary outcomes

Search methods for identification of studies

Electronic searches

Searching other resources

Data collection and analysis

Selection of studies

1.

1. Number screened, entered and completed.

2. Descriptive summaries: particpant characteristics, by intervention class.

3. Descriptive summaries: intervention characteristics, by intervention class.

4. EDU Study characteristics.

5. SUP Study characteristics.

6. BEH Study characteristics.

7. MIX Study characteristics.

Data extraction and management

Categorisation of studies

Assessment of risk of bias in included studies

Measures of treatment effect

Effect measures

Handling skewed data

Unit of analysis issues

Studies with multiple treatment groups

Dealing with missing data

Assessment of heterogeneity

Assessment of reporting biases

Data synthesis

Subgroup analysis and investigation of heterogeneity

Sensitivity analysis

'Summary of findings' tables

Results

Description of studies

Results of the search

Included studies

Study design

Participants

Interventions

Study duration, number of intervention episodes, total contact time

Outcomes

Endpoints reported

Outcomes: exclusion of specific studies from selected meta‐analyses

3.1. Analysis.

6.10. Analysis.

Excluded studies

Risk of bias in included studies

Risk of bias 2: CPAP device usage

Risk of bias in included studies

2.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 CPAP Device Usage (hours/night)	8	578	Mean Difference (IV, Fixed, 95% CI)	1.31 [0.95, 1.66]
2 CPAP Device Usage (hours/night), sensitivity analysis: adherence in control group < four hours/night	6	525	Mean Difference (IV, Fixed, 95% CI)	1.32 [0.93, 1.72]
3 N deemed adherent (≥ four hours/night)	6	549	Odds Ratio (M‐H, Fixed, 95% CI)	1.70 [1.20, 2.41]
4 Withdrawal	10	939	Odds Ratio (M‐H, Fixed, 95% CI)	0.66 [0.44, 0.98]
5 Epworth Sleepiness Scale (Endpoint scores)	5	271	Mean Difference (IV, Random, 95% CI)	‐2.42 [‐4.27, ‐0.57]
6 AHI on treatment ‐ Endpoint	2	89	Mean Difference (IV, Fixed, 95% CI)	‐0.95 [‐2.25, 0.35]
7 Quality of Life ‐ Comparison of Values at Endpoint	3	228	Std. Mean Difference (IV, Fixed, 95% CI)	0.00 [‐0.26, 0.26]
7.1 QoL: FOSQ ‐ Endpoint	2	200	Std. Mean Difference (IV, Fixed, 95% CI)	0.01 [‐0.26, 0.29]
7.2 QoL: SF‐36 (PH) ‐ Endpoint	1	28	Std. Mean Difference (IV, Fixed, 95% CI)	‐0.07 [‐0.82, 0.67]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 CPAP Device Usage (hours/night)	11	4509	Mean Difference (IV, Random, 95% CI)	0.82 [0.20, 1.43]
2 CPAP Device Usage, sensitivity analysis: adherence in control group < four hours/night	2	343	Mean Difference (IV, Random, 95% CI)	1.77 [0.21, 3.34]
3 N deemed adherent (≥ four hours/night)	9	4015	Odds Ratio (M‐H, Random, 95% CI)	1.71 [1.08, 2.72]
4 Withdrawal	11	4956	Odds Ratio (M‐H, Random, 95% CI)	0.61 [0.28, 1.30]
5 Quality of LIfe: Comparison of Change from Baseline Values	2	3012	Std. Mean Difference (IV, Random, 95% CI)	0.45 [0.12, 0.78]
5.1 QoL: FOSQ‐10 ‐ Change from Baseline	1	176	Std. Mean Difference (IV, Random, 95% CI)	0.25 [‐0.05, 0.54]
5.2 QoL: SF‐36 (PH) ‐ Change from Baseline	1	2836	Std. Mean Difference (IV, Random, 95% CI)	0.59 [0.52, 0.67]
6 Quality of Life: Comparison of Values at Endpoint	4	3191	Std. Mean Difference (IV, Random, 95% CI)	0.45 [0.06, 0.83]
6.1 QoL: FOSQ ‐ Endpoint	1	177	Std. Mean Difference (IV, Random, 95% CI)	0.10 [‐0.19, 0.40]
6.2 QoL: SF‐36 (PH) ‐ Endpoint	3	3014	Std. Mean Difference (IV, Random, 95% CI)	0.59 [‐0.01, 1.19]
7 Anxiety Symptom Rating ‐ Comparison of Values at Endpoint	3	333	Std. Mean Difference (IV, Random, 95% CI)	‐0.19 [‐0.47, 0.09]
7.1 DASS ‐ Anxiety	1	177	Std. Mean Difference (IV, Random, 95% CI)	‐0.03 [‐0.32, 0.27]
7.2 BAI	1	65	Std. Mean Difference (IV, Random, 95% CI)	‐0.15 [‐0.63, 0.34]
7.3 STAI ‐ State	1	91	Std. Mean Difference (IV, Random, 95% CI)	‐0.49 [‐0.92, ‐0.06]
8 Depression Symptom Rating ‐ Comparison of Values at Endpoint	4		Std. Mean Difference (IV, Fixed, 95% CI)	Totals not selected
8.1 BDI	1		Std. Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.2 HADS ‐ Depression	2		Std. Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.3 DASS ‐ Depression	1		Std. Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
9 Epworth Sleepiness Scale Score	7		Mean Difference (IV, Random, 95% CI)	Totals not selected
9.1 ESS: Endpoint Scores	5		Mean Difference (IV, Random, 95% CI)	0.0 [0.0, 0.0]
9.2 ESS: Change from Baseline	3		Mean Difference (IV, Random, 95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 EDU: CPAP Device Usage (hours/night), original EDU study classification	8	1095	Mean Difference (IV, Fixed, 95% CI)	0.48 [0.21, 0.76]
2 SUP: CPAP Device Usage (hours/night), original SUP study classification	14	1534	Mean Difference (IV, Fixed, 95% CI)	0.58 [0.36, 0.81]
3 BEH: CPAP Device Usage (hours/night), original BEH study classification	9	625	Mean Difference (IV, Fixed, 95% CI)	1.47 [1.12, 1.83]
4 EDU: CPAP Device Usage (hours/night), exclude HIGH 'Risk of bias' studies	4	642	Mean Difference (IV, Random, 95% CI)	0.98 [0.07, 1.89]
5 SUP: CPAP Device Usage (hours/night), exclude HIGH 'Risk of bias' studies	5	728	Mean Difference (IV, Fixed, 95% CI)	0.75 [0.42, 1.09]
6 BEH: CPAP Device Usage (hours/night), exclude HIGH 'Risk of bias' studies	4	340	Mean Difference (IV, Fixed, 95% CI)	1.05 [0.57, 1.53]
7 MIX: CPAP Device Usage (hours/night), exclude HIGH 'Risk of bias' studies	5		Mean Difference (IV, Random, 95% CI)	Totals not selected

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 EDU: CPAP Device Usage (hours/night)	10	1128	Mean Difference (IV, Random, 95% CI)	0.85 [0.32, 1.39]
1.1 Intervention Duration > 4 weeks	3	453	Mean Difference (IV, Random, 95% CI)	0.33 [‐0.10, 0.77]
1.2 Intervention Duration ≤ 4 weeks	7	675	Mean Difference (IV, Random, 95% CI)	1.20 [0.39, 2.01]
2 EDU: CPAP Device Usage (hours/night)	9	836	Mean Difference (IV, Random, 95% CI)	0.98 [0.36, 1.59]
2.1 Contact Episodes: > 1	6	514	Mean Difference (IV, Random, 95% CI)	1.20 [0.41, 2.00]
2.2 Contact Episodes: 1 (single)	3	322	Mean Difference (IV, Random, 95% CI)	0.40 [‐0.06, 0.86]
3 EDU: CPAP Device Usage (hours/night)	8	808	Mean Difference (IV, Random, 95% CI)	1.04 [0.37, 1.71]
3.1 Contact Time > 60 min	3	293	Mean Difference (IV, Random, 95% CI)	1.46 [0.22, 2.71]
3.2 Contact Time ≤ 60 min	5	515	Mean Difference (IV, Random, 95% CI)	0.61 [0.00, 1.22]
4 SUP: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	13	1426	Mean Difference (IV, Random, 95% CI)	0.70 [0.36, 1.05]
4.1 Intervention Duration > 12 weeks	4	530	Mean Difference (IV, Random, 95% CI)	0.49 [‐0.53, 1.51]
4.2 Intervention duration ≤12 weeks	9	896	Mean Difference (IV, Random, 95% CI)	0.72 [0.43, 1.01]
5 SUP: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	13	1426	Mean Difference (IV, Random, 95% CI)	0.70 [0.36, 1.05]
5.1 Intervention entailed Automated Contact Only	4	513	Mean Difference (IV, Random, 95% CI)	0.26 [‐0.51, 1.04]
5.2 Intervention included Human Contact	9	913	Mean Difference (IV, Random, 95% CI)	0.84 [0.52, 1.17]
6 SUP: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	13	1426	Mean Difference (IV, Fixed, 95% CI)	0.65 [0.41, 0.89]
6.1 Scheduled, Human Interaction	3	136	Mean Difference (IV, Fixed, 95% CI)	1.43 [0.61, 2.24]
6.2 Automated and/or Ad‐hoc Human Contact only	10	1290	Mean Difference (IV, Fixed, 95% CI)	0.58 [0.33, 0.83]
7 BEH: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	8	577	Mean Difference (IV, Random, 95% CI)	1.31 [0.95, 1.66]
7.1 BEH: Intervention Duration > 4 weeks	3	208	Mean Difference (IV, Random, 95% CI)	1.21 [0.60, 1.82]
7.2 BEH: Intervention Duration ≤ 4 weeks	5	369	Mean Difference (IV, Random, 95% CI)	1.38 [0.80, 1.95]
8 BEH: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	8	577	Mean Difference (IV, Random, 95% CI)	1.31 [0.95, 1.66]
8.1 BEH: Contact Episodes: > 1	7	537	Mean Difference (IV, Random, 95% CI)	1.35 [0.94, 1.77]
8.2 BEH: Contact Episodes: 1 (single)	1	40	Mean Difference (IV, Random, 95% CI)	1.10 [0.26, 1.94]
9 BEH: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	8	577	Mean Difference (IV, Random, 95% CI)	1.31 [0.95, 1.66]
9.1 BEH: Contact Time > 60	6	437	Mean Difference (IV, Random, 95% CI)	1.15 [0.71, 1.60]
9.2 BEH: Contact Time ≤ 60	2	140	Mean Difference (IV, Random, 95% CI)	1.56 [0.68, 2.44]
10 MIX: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	11	4509	Mean Difference (IV, Random, 95% CI)	0.82 [0.20, 1.43]
10.1 Intervention Duration > 4 weeks	8	4178	Mean Difference (IV, Random, 95% CI)	1.22 [0.60, 1.83]
10.2 Intervention Duration ≤ 4 weeks	3	331	Mean Difference (IV, Random, 95% CI)	‐0.31 [‐0.83, 0.21]
11 MIX: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	10	4242	Mean Difference (IV, Random, 95% CI)	0.79 [0.10, 1.48]
11.1 Contact Episodes: > 1	9	4036	Mean Difference (IV, Random, 95% CI)	0.98 [0.32, 1.63]
11.2 Contact Episodes: 1 (single)	1	206	Mean Difference (IV, Random, 95% CI)	‐0.60 [‐1.33, 0.13]
12 MIX: Subgroup Analysis ‐ CPAP Device Usage (hours/night)	10	4242	Mean Difference (IV, Random, 95% CI)	0.79 [0.10, 1.48]
12.1 Contact Time > 60 min	6	3751	Mean Difference (IV, Random, 95% CI)	1.45 [0.73, 2.16]
12.2 Contact Time ≤ 60 min	4	491	Mean Difference (IV, Random, 95% CI)	‐0.15 [‐0.56, 0.27]

Methods	Randomised parallel‐group trial.
Participants	N = 12 existing patients at investigator sleep centre with OSA. Participants had received prior treatment with CPAP Inclusion criteria: > 55 years of age, RDI (AHI): > 10, Mini Mental Status Examination: > 25 Exclusion criteria: other ICSD, other treatment for apnoea, claustrophobia Baseline characteristics: mean age: 63.4, AHI: 43.5, Desaturation: 77.05 ± 9.47. Baseline characteristics not reported: gender, BMI, ESS. Country: USA
Interventions	Participants were randomised into experimental intervention (n = 6) or control (n = 6). Intervention: two sessions. Session 1: review of participants' sleep data; symptoms; review of performance of cognitive tests; review of importance of treatment; review of PSG and CPAP; discussion of advantages and disadvantages of treatment; development of goals for therapy. Session 2: examination of compliance data for week one; discussion of noticeable changes with treatment; discussion of changes not apparent (hypertension/cardiac problems); troubleshooting discomfort; discussion of realistic aims of treatment; review of treatment goals Control: two sessions: general discussion of sleep architecture and opinions on sleep clinic Study duration: 12 weeks
Outcomes	Machine usage (hours/night) at 1 week, 4 weeks, 3 months*. N of adherent participants ( ≥ 6 hours per night of usage) Vigilance testing
Notes	* Indicates primary outcome analysed in this review
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation by 'urns', stratification by age, RDI, nadir O₂ pretreatment, vigilance
Allocation concealment (selection bias)	Unclear risk	Information not available
Blinding (performance bias and detection bias)   All outcomes	High risk	Not done for treatment group assignment 'None of the participants were told that their CPAP machines were measuring their compliance via internal microprocessors'
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	Information not available
Selective reporting (reporting bias)	Unclear risk	Information not available
Other bias	Unclear risk	Information not available
Bias arising from the randomisation process (ROB2, primary outcome)	High risk	Authors describe randomisation procedures in METHODS: "...participants were randomised into one of two groups (experimental or control) based on their age, RDI, and nadir oxygen level pretreatment. This type of randomisation involves placing participants into groups based on the current group averages for variables to be randomised. For example, if the average age of group 1 is 50 years and the average age of group 2 is 60 years, the new 40‐year‐old subject would be placed in group 2 to approximate the first group's average age. Accordingly, the two groups were not significantly different on age, education, RDI, or nighttime oxygen saturation." Based upon cited reference (Stout et al, 1994) for these procedures, this suggests a form of urn randomisation was used. Urn randomisation may be adequate (Cochrane Risk of bias 2 reference manual) and even recommended to ensure balance with small sample sizes, where major imbalance could occur with higher probability. (Hedden, et al, 2006 Randomisation in substance abuse clinical trials; Wei & Lachin, Properties of the urn randomisation in clinical trials. Controlled Clinical Trials 1998;9(4):345‐64).    No reference to allocation concealment method.
Bias due to deviations from intended interventions (ROB2, primary outcome)	Low risk	No deviations documented; none suspected based upon review. Authors report, "Machines were switched unexpectedly in the middle of the study for three participants for reasons unrelated to treatment. Calculating cumulative run time at the 12‐week follow‐up instead of night‐by‐night figures accommodated this event. participants' cumulative data were then divided by the number of nights with the machine to obtain average daily run time." This deviation was likely unrelated to experimental context.
Bias due to missing outcome data (ROB2, primary outcome)   All outcomes	Low risk	Information not available
Bias in measurement of the outcome (ROB2, primary outcome)   All outcomes	Unclear risk	Outcome measured using objective CPAP usage data. Insufficient information. All participants received the same CPAP device at the start of the trial. However, authors report, "Machines were switched unexpectedly in the middle of the study for three participants for reasons unrelated to treatment. Calculating cumulative run time at the 12‐week follow‐up instead of night‐by‐night figures accommodated this event. Participants' cumulative data were then divided by the number of nights with the machine to obtain average daily run time." The group assignment of these three participants was not reported and the meaning of 'machines were switched' is unclear. If this implies a switch to a different device make or model, it is possible that outcome measurement could have differed between the intervention group. Given the small N and depending upon the distribution of the 'switches' between groups, this could have impacted effect size estimates. Outcome "assessor" is CPAP device: no knowledge of allocation possible.
Bias in selection of the reported result (ROB2, primary outcome)   All outcomes	Unclear risk	No protocol, abstract, clinical trials entry available for comparison. Results presented were in accordance with the plan specified in the Methods section of the publication. Methods section indicates multiple outcome time points (for primary adherence outcome) were planned. Results section reports each planned time point. No threshold‐defined adherence outcomes were specified in Methods; one was reported in results.
Overall risk of bias (ROB2, primary outcome)   Machine usage	High risk	‐

Methods	Open‐label, parallel‐arm, RCT.
Participants	N = 83 participants with OSA Inclusion criteria: AHI 4%, ≥ 10 or AHI 3%, ≥ 15; 45 to 75 years with established CVD or cardiometabolic disease (established coronary artery disease (≥ 70% stenosis in at least one major coronary artery), prior myocardial infarction, coronary artery revascularisation procedure, Ischaemic stroke, or diabetes) OR 55 to 75 years with at least three CVD risk factors (male sex, BMI ≥ 30, hypertension, dyslipidaemia, and ≥ 10 pack‐years of smoking). Exclusion criteria: cardiovascular event < 4 months before enrolment, prior CPAP, ESS > 14 of 24, drowsy driving within 2 years, commercial driving, or an uncontrolled medical condition (including CSA, heart failure, uncontrolled hypertension, severe hypoxaemia, anaemia, and renal insufficiency). Baseline characteristics: 33% female. Mean age 63.8 (NR). Mean AHI 22.8. Mean ESS NR. Mean BMI 31.1. Country: USA
Interventions	Eligible participants entered a run‐in phase before randomisation, consisting of 14 days wearing a nasal CPAP mask during sleep (without a CPAP device). Participants who reported using the mask during the majority of the run‐in and who were willing to continue using the mask were eligible for randomisation. Randomisation took place in a 1:1:1:1 ratio with a block size of 4, based on three stratification factors: diagnostic study (full night or split night with titration), site, CVD status (established or risk factors) to one of four study arms (two control conditions, two treatment conditions): conservative medical therapy (n = 44), sham CPAP (n = 42), active CPAP (n = 42), or active CPAP +ME (n = 41). Bakker 2016 reported only the active CPAP and CPAP + ME arms. Intervention (Active CPAP + ME): overall goal of each ME session was to resolve the participants' ambivalence toward establishing consistent CPAP usage patterns and increase their confidence toward using CPAP regularly. Each participant was encourage to set concrete goals regarding their future CPAP use and identify rewards that they could provide themselves when those goals were achieved. ME was delivered during 1‐hour in‐person sessions at baseline and week 1, which included an educational video, and during phone calls of 10 to 30 minutes with the same psychologist at weeks 3, 4, 8, 12, 20, and 32. Control (Active CPAP): CPAP Study duration: 12 months.
Outcomes	CPAP usage (hours/night) at 6*, 12 months
Notes	* Indicates primary outcome analysed in this Review.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomization took place in a 1:1:1:1 ratio with a block size of 4, based on three stratification factors: diagnostic study (full night or split night with titration), site (BWH, BIDMC, or Joslin), CVD status (established or risk factors). Randomization was performed using a data‐entry system linked to an off‐site server holding the sequences."
Allocation concealment (selection bias)	Unclear risk	Insufficient information to determine sufficiency of sequence concealment: Sequences were concealed at off‐site location. Block sizes were fixed, so last assignment to each block could be predicted, but only likely to occur if investigators were aware of block sizes.
Blinding (performance bias and detection bias)   All outcomes	High risk	No evidence of blinding of participants, personnel or outcome assessors. Study had subjective outcomes, so knowing group assignment could influence these outcomes.
Incomplete outcome data (attrition bias)   All outcomes	Low risk	Data were available for all, or nearly all, participants randomised.
Selective reporting (reporting bias)	Low risk	Study protocol is not available, but thorough analysis of information presented in study's NCT archive does not suggest that outcomes of interest were chosen after data analysis already commenced.
Other bias	Low risk	No baseline imbalances or reported deviations from intended intervention.
Bias arising from the randomisation process (ROB2, primary outcome)	Unclear risk	Authors report, "Analyses in this paper compare the active CPAP and CPAP + ME arms only. Randomization took place in a 1:1:1:1 ratio with a block size of 4, based on three stratification factors: diagnostic study (full night or split night with titration), site (BWH, BIDMC, or Joslin), CVD status (established or risk factors). Randomization was performed using a data‐entry system linked to an off‐site server holding the sequences. Participants randomly assigned to a CPAP group immediately underwent secondary randomisation to use a device by one of two manufacturers (Philips Respironics or ResMed), using a randomisation sequence with a block size of 2." From Protocol (Yaggi 2016): 255 patients with TIA or stroke are randomly assigned using a 1:1:1 (control:standard PAP: enhanced PAP) randomisation scheme to either usual care or a home‐based diagnosis and treatment approach that includes ambulatory polysomnography and initiation of PAP for patients with sleep apnoea (Figure 1). Control patients could undergo diagnosis and treatment of sleep apnoea if suspected as part of usual clinical care. The randomisation is stratified by centre (Connecticut or Indiana) and neurologic event type (TIA or stroke)...."    Random component used for sequence generation not explicitly described. Insufficient information to determine sufficiency of sequence concealment: Sequences were concealed at off‐site location. Block sizes were fixed, so last assignment to each block could be predicted, but only likely to occur if investigators were aware of block sizes. Authors provide a tabular summary of baseline characteristics for participants randomised to CPAP+ME and CPAP‐only intervention arms, and report in text: "The two groups were comparable at baseline in terms of age, sex, anthropometrics, race or ethnicity, and cardiovascular risk factors (Table 5)."
Bias due to deviations from intended interventions (ROB2, primary outcome)	Low risk	Yaggi 2016 report that participants were unblinded. (p. 5) Deviation from protocol documented by authors: The original trial design included follow‐up for 12 months; however, participants randomly assigned after January 2013 were restricted to 6 months of follow‐up. Our primary analysis of CPAP adherence therefore took place for 6 months, rather than 12." This deviation is unlikely to have affected the outcome. Authors report, "All analyses were intention‐to‐treat." Additionally, all outcome measures appear to derive from all randomised participants in the two relevant treatment arms. Protocol deviation was unlikely to have contributed to biased effect estimates as it was balanced across intervention arms and likely unrelated to outcome.
Bias due to missing outcome data (ROB2, primary outcome)   All outcomes	Low risk	Six‐month outcome data available for nearly all randomised participants. In addition to having primary outcome (CPAP usage) data for nearly all participants, authors documented reasons for missing adherence data and conducted sensitivity analyses, determining that the finding of no differences in adherence between groups was robust when a value of zero was assigned to missing usage data and when examining complete data only.
Bias in measurement of the outcome (ROB2, primary outcome)   All outcomes	Low risk	Outcome measured using objective CPAP usage data. Published report notes, "All participants were provided with either a REMstar    Pro CPAP (Respironics Inc. Murrysville PA) device with a data‐storage Smart‐Card, or a Sandman Goodnight 420 Series Auto HH (Covidien, Mansfield, MA) which allowed usage data to be directly downloaded from the machine or via a memory key. Reviewers contacted authors to request information as to the distribution of CPAP device make across intervention arms. Authors responded (email) reporting, "Our CPAP machines were provided for the study by Respironics – REMstar Auto with C Flex or REMstar Pro M Series." Thus, the information provided by authors in personal correspondence suggests that no participants received the Sandman Goodnight 420 Series Auto HH and, therefore, that outcome measurement should not have differed between intervention groups. Outcome "assessor" is CPAP device: no knowledge of allocation possible.
Bias in selection of the reported result (ROB2, primary outcome)   All outcomes	Unclear risk	NCT01261390: Original primary outcome measures of BestAir trial (submitted 15 Dec 2010) was "Effectiveness of continuous positive airway pressure therapy on cardiovascular disease, using mean 24 hour systolic blood pressure as the trial's primary endpoint. [ Time Frame: 3 years ]". Current primary outcome measures (submitted 18 Apr 2017) include those of interest in this review: "Difference in CPAP Adherence by Active Treatment Arm [ Time Frame: 6‐months ] Original secondary outcome measure (submitted 15dec2010): "Recruitment and retention rates of patients with moderate to severe obstructive sleep apnoea and cardiovascular disease risk factors or established CVD participating in a controlled trial. [ Time Frame: 3 years ]"    "Adherence to CPAP therapy was tracked remotely by modem transmission. Outcome reported is mean hours of PAP use per night at the 6‐month time point. Comparison is between those with and without assignment to Motivational Enhancement as part of treatment randomisation." Current secondary outcome measures of relevance to our review (submitted 18 Apr 2017): Change in ESS, SAQLI, SF‐36, PHQ‐8 [6 & 12 months.    Though it appears that CPAP adherence was a target of the intervention from the outset (i.e. it is repeatedly mentioned as a focus of attention in description of the active treatment arms), it does not appear to have been an outcome of interest at the time of design. Rather, as described in the protocol (described in Yaggi 2016), adherence was a primary process measure (and one likely to impact the primary physiological outcome of interest). Study primary completion date (March 2014, final collection date for primary outcome measure) occurred before current primary/secondary outcome measures posted to clinicaltrials.gov. However, the time stamps provided in NCT entry are merely the date that these outcomes were entered into the electronic system and likely do not represent the date that decisions about additional outcome measures were made. Thus, it is possible that all primary/secondary outcomes were finalised before unblinded outcome data were available for analysis. Decision to change primary CPAP adherence outcome from 12‐month to 6‐month endpoint likely a consequence of a change in design/follow‐up necessitated by factors unrelated to the outcome that required follow‐up to shorten for participants enrolled after January, 2013. Moreover, for those participants with outcome data at 12 months, the results were similar.
Overall risk of bias (ROB2, primary outcome)   Machine usage	Unclear risk	‐

Methods	Randomised, parallel‐group study
Participants	N = 133 newly diagnosed moderate‐to‐severe OSAS patients Inclusion criteria: newly diagnosed, moderate to severe OSA, CPAP‐naive Exclusion criteria: use of sedatives, drug abuse, cardiac co‐morbidities, COPD, other sleep disorders Baseline characteristics, by group: Intervention group: age: 53.7, Male sex: 82%, AHI 61, ESS: 10.3, BMI: 33.2. Control group: age: 54.4, Male sex: 70%, AHI: 57.4, ESS: 12.4, BMI: 33 Country: Turkey
Interventions	Participants were randomised into video education intervention (n = 66) or control (n = 67). Intervention: 10‐minute videotape on OSA, its consequences and CPAP therapy. In addition, routine information on diagnosis and treatment of OSA given by physician Control: standard information on OSA and CPAP therapy given by the same physician Study duration: 24 weeks
Outcomes	N of adherent participants (CPAP use for at least four hours/night for at least 70% of nights at 1, 3*, 6 months Sleepiness (ESS) Factors predicting CPAP adherence Withdrawals
Notes	Unpublished information on study design and outcomes obtained from study authors
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation by a set of numbers prepared and randomly assigned by a clinician not involved in the study
Allocation concealment (selection bias)	Low risk	Randomisation by a third party
Blinding (performance bias and detection bias)   All outcomes	Unclear risk	The primary investigator and the statistician were blinded to the study group assignment. Participants were aware of machine usage monitoring. Given the nature of the intervention, it is unlikely that participant blinding was achieved
Incomplete outcome data (attrition bias)   All outcomes	Low risk	All participants completed the study, and no data were missing
Selective reporting (reporting bias)	Unclear risk	No Information.
Other bias	Unclear risk	No Information.
Bias arising from the randomisation process (ROB2, primary outcome)	Unclear risk	Only information provided as to the randomisation procedures used was within METHODS: "The study used a randomised two‐group design. Out of 133 patients, 66 were informed about OSAS and CPAP therapy by the same doctor and also received visual education by videotape (video group), whereas only information was given to 67 of them (control group). All the patients in the video group received video education after CPAP titration, and the duration between video education and initiation of CPAP treatment was approximately 1 week." No reference to random component or allocation concealment method. Key baseline characteristics (age, gender, BMI, AHI) were reported for all randomised participants and differences were insignificant (P values reported), consistent with chance.
Bias due to deviations from intended interventions (ROB2, primary outcome)	Low risk	No deviations documented; none suspected based upon review. Authors report "There was no dropout during the follow‐up period as the patients were called up in case of missing an appointment." Additionally, results are reported for all randomised participants.
Bias due to missing outcome data (ROB2, primary outcome)   All outcomes	Low risk
Bias in measurement of the outcome (ROB2, primary outcome)   All outcomes	Low risk	Outcome measured using objective CPAP usage data. Each intervention group outcome data ascertained via automated CPAP device monitoring; devices identical or sufficiently similar (i.e. similar distributions of CPAP device make) across groups. Outcome "assessor" is CPAP device: no knowledge of allocation possible.
Bias in selection of the reported result (ROB2, primary outcome)   All outcomes	High risk	No protocol, abstract, clinical trials entry available for comparison. Results presented were in accordance with the plan specified in the METHODS section of the publication. No information as to whether analysis plan was finalized before unblinded outcome data were available for analysis. Methods section indicates that multiple time points planned; each planned outcome reported. Methods indicate one threshold definition. However, the decision to use only a threshold definition, and not present average usage upon which that threshold was calculated, is inconsistent with standard reporting practices in the field and suggests that the numerical result being assessed is likely to have been selected based on the results.
Overall risk of bias (ROB2, primary outcome)   Machine usage	High risk	‐

Methods	Randomised, parallel‐group study.
Participants	N= 3100 patients with newly diagnosed sleep apnoea randomised to either the standard group (usual follow‐up care) or the intensive group (additional visits, telephone calls, and education). Inclusion criteria: newly diagnosed with OSAHS by PSG, moderate‐to‐severe OSAHS, no history of previous CPAP therapy, and above‐elementary school education. Exclusion criteria: refusal to participate, refusal of CPAP therapy, CSA syndromes, obesity hypoventilation syndrome, restrictive pulmonary and restrictive chest wall diseases, severe CHF, a history of life‐threatening arrhythmias, severe cardiomyopathy, LTOT, family or personal history of mental illness, drug or alcohol abuse, severe cognitive impairment, concurrent oncological diseases, and a history of narcolepsy or restless legs syndrome. Baseline characteristics: 25% female. Mean age 55.6 (±10.2). Mean AHI 52. Mean ESS 12.1. Mean BMI 37.8. Country: Greece
Interventions	Eligible patients (n = 3100) were randomly assigned in a 1:1 ratio to receive either the standard intervention (n = 1550), of usual follow‐up care, or the intensive intervention (n = 1550), with augmented follow‐up care based on additional appointments at the CPAP clinic, telephone calls and education. Intensive intervention: patients received the same features as standard group, with the addition of follow‐up visits involving patients' partners or family. All patients attended a 15‐minute video education session cover OSAHS‐related topics, including the syndrome itself, treatment options, and the benefits of adherence to therapy. This was followed by a 10‐to 15‐minute lecture used to reinforce key concepts. During the first week of CPAP set‐up, patients were contacted by the nurse, on the second and seventh day, via telephone in order to discuss any concerns they might have regarding air pressure, mask fitting, leaks and other issues as they arose. During the first month of treatment, patients were instructed to keep a sleep diary, and were reviewed by a sleep specialist on the 15^th and 30^th day of treatment. Standard care: patients were reviewed in the outpatient sleep clinic at 1‐month, at 3‐month intervals during the first years, and every 6 months afterwards. During these appointments, a clinical assessment was made and patients were further encouraged to use the device. If there were doubts about compliance, the referring physician made personal contact with the patient in order to resolve barriers to adequate compliance. Study duration: 2 years
Outcomes	CPAP usage (hours/night) at 1 month, 2 years* N of adherent participants ( ≥ 4 hours/night for ≥ 70% of nights) Sleepiness (ESS) QoL (SF‐36) Depressive symptoms (BDI) Withdrawals Hospitalisations CVD‐related deaths Cost‐effectiveness Chronological data were obtained from the CPAP machine at each follow‐up appointment. Self‐reported number of nights per week and hours per night were obtained for comparison against data obtained from CPAP machine. Regular CPAP compliance was defined as using the therapy for an average of 4 hours per night on at least 70% of the nights.The estimated costs of each intervention were calculated and compared between groups.
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Eligible patients (n = 3100) were randomly assigned in a 1:1 ratio to receive either the standard intervention (n = 1550), of usual follow‐up care, or the intensive intervention (n = 1550), with augmented follow‐up care based on additional appointments at the CPAP clinic, telephone calls and education. Randomisation was performed using a computer‐generated list of random numbers.
Allocation concealment (selection bias)	Unclear risk	No reference to allocation concealment method.
Blinding (performance bias and detection bias)   All outcomes	High risk	No evidence of blinding of participants, personnel or outcome assessors. Study had subjective outcomes, so knowing group assignment could influence these outcomes.
Incomplete outcome data (attrition bias)   All outcomes	High risk	1349/1550 and 1501/1550 in the standard and intensive groups (respectively) either discontinued the intervention or were "lost to follow‐up". Considerably more people dropped out of the standard intervention group (therefore missing outcome data are unbalanced in numbers across intervention groups). This would not affect adherence data (which can be predicted to be 0 for those who "discontinued intervention"), but would affect subjective outcomes.
Selective reporting (reporting bias)	Unclear risk	No information as to whether analysis plan was finalised before unblinded outcome data were available for analysis.
Other bias	Low risk	No baseline imbalances or reported deviations from intended intervention.
Bias arising from the randomisation process (ROB2, primary outcome)	Unclear risk	Authors report, "Eligible patients (n=3100) were randomly assigned in a 1:1 ratio to receive either the standard intervention (n=1550), of usual follow‐up care, or the intensive intervention (n=1550), with augmented follow‐up care based on additional appointments at the CPAP clinic, telephone calls and education. Randomisation was performed using a computer‐generated list of random numbers."  No reference to allocation concealment method. Key baseline characteristics (age, gender, BMI, AHI) were reported and differences were insignificant (P values reported), consistent with chance.
Bias due to deviations from intended interventions (ROB2, primary outcome)	Low risk	Authors report, "Patients were blinded to the group to which they were allocated and were followed for a minimum of 2 years." Methods for blinding were not described.  Authors specify only that the PSG scorer was blinded to 'the origin of the data." No deviations documented; none suspected based upon review. AUthors report, "Data were normally distributed. Numerical variables are presented as mean SD. Intention‐to‐treat analysis was carried out, in which all patients receiving the allocated interventions were included in the analysis." Authors do not report on missing data or how missing endpoint values were accounted for (e.g. LOCF, imputation, substitution of 0 hours use).
Bias due to missing outcome data (ROB2, primary outcome)   All outcomes	Low risk	Authors report, "155 of the 3100 patients, 124 receiving standard support and 31 intensive support, were lost to follow‐up: 77 (4.9%) patients in the standard group and 18 (1.1%) in the intensive group had stopped using CPAP, and 10 patients in the standard group and four in the intensive support group died after randomisation (fig. 1). All 3100 patients were included in the final analysis." Authors do not report on missing data, so it is unclear if data were missing for those who did not complete the study and, if so how these missing endpoint values were accounted for (e.g. LOCF, imputation, substitution of 0 hours use).
Bias in measurement of the outcome (ROB2, primary outcome)   All outcomes	Unclear risk	Outcome measured using objective CPAP usage data. Each intervention group outcome data ascertained via automated CPAP device monitoring. Unable to confirm with study author that distribution of CPAP device makes did not differ between intervention arms. Outcome "assessor" is CPAP device: no knowledge of allocation possible.
Bias in selection of the reported result (ROB2, primary outcome)   All outcomes	High risk	ClinicalTrials.gov entry (NCT02016339) indicates that the original primary outcome measure was the same as the current primary outcome measure, "Effect of intensive intervention on CPAP adherence [ Time Frame: 24 months ]" (submitted 13 Dec 2013). Final data collection date for primary outcome was June 2013. NCT outcome is the same as that presented in published report. No information as to whether analysis plan was finalized before unblinded outcome data were available for analysis. Methods section (but not NCT entry) indicates that multiple analyses of CPAP adherence outcomes were planned and all were reported in Results. Though the authors report 24‐month outcomes as specified in NCT trial listing, their choice of definitions for CPAP usage rates is atypical. Specifically, authors define the CPAP usage/night outcome as "Hours per night, on nights CPAP was used." This definition of the CPAP usage/adherence outcome was not pre‐specified (in NCT entry) and may substantially overestimate CPAP usage (in both groups) because all nights not used are excluded from numerator and denominator. Since mean use per day was likely also calculated, the decision to report mean use per effective day suggests that the numerical result being assessed was selected on the basis of the results from multiple outcome measurements.
Overall risk of bias (ROB2, primary outcome)   Machine usage	High risk	‐

Methods	Randomised parallel‐group trial
Participants	N = 40 participants with OSA (about to start or already receiving CPAP) recruited from clinic. Baseline characteristics: Mean age 51.7. Mean AHI 49.4. ESS 10.9 ± 5.1. Lowest 0₂ Sat 75.6% (± 14.4). MSLT 6 (± 3.9) Country: USA
Interventions	No information provided as to the group allocation of all randomised participants. Allocation Ns only available for the 33 participants who completed the study: Intervention group 1 (n = 12), Intervention group 2 (n = 14), control (n = 7). Intervention 1: telephone call each week during trial (max trial time of two months) Intervention 2: two printed documents Control: no additional support Study duration: 8 weeks
Outcomes	Machine usage (hours/night) at 1 to 2 months Dropouts/Lost‐to‐follow‐up
Notes	Two of 33 used Bi‐PAP. Both CPAP‐naive users and those who had been on CPAP before trial were studied. Reading done at enrolment and at between 1 to 2 months after enrolment Difference in AHI between active and control groups at baseline. Trialists included two intervention arms, one educational and one supportive. Intervention 1 (telephone support) vs. Control included in Supportive meta‐analysis. Intervention 2 (educational documents) vs. control included in educational meta‐analysis.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random numbers table
Allocation concealment (selection bias)	Unclear risk	Information not available
Blinding (performance bias and detection bias)   All outcomes	High risk	Not done for treatment group assignment Participants' readout of CPAP machine usage data during telephone call to clinic
Incomplete outcome data (attrition bias)   All outcomes	High risk	Non‐completers excluded from analysis
Selective reporting (reporting bias)	Unclear risk	No Information.
Other bias	Unclear risk	No Information.
Bias arising from the randomisation process (ROB2, primary outcome)	Unclear risk	Authors report, "On the basis of a random number table, each subject was assigned to one of three intervention groups."  No reference to allocation concealment method. Key baseline characteristics (age, gender, AHI) were reported for all randomised participants and differences were reported to be non‐significant (no P values presented). BMI comparisons were not reported.
Bias due to deviations from intended interventions (ROB2, primary outcome)	High risk	No deviations documented; none suspected based upon review. According to the report, 40 participants signed informed consent and were enrolled. Though not explicitly stated by authors, it appears these 40 participants were randomised. However, as noted by authors, "Of the 40 enrolled subjects, five were impossible to reach by phone to establish counter readings and two reported counter readings that were physically impossible, leaving 33 participants (21 men) aged 51.7 +/‐ 11.0 years [ mean +/‐ standard deviation (SD)] who completed the protocol and formed the basis for this report." Therefore, it appears that a per‐protocol analysis was used and no information was presented as to which group(s) the lost participants had been allocated. 17.5% of likely randomised participants were not included in the report.
Bias due to missing outcome data (ROB2, primary outcome)   All outcomes	High risk	Outcome data were not available for 17.5% of likely randomised participants. Neither analyses to correct for bias nor sensitivity analyses were conducted. Yes, reported reasons for exclusion were five were "impossible to reach by phone to establish counter readings" and "reported counter readings that were physically impossible." Authors did not report the group allocation of the seven participants who did not complete the study. Therefore, we do not know if there were differences between intervention groups in proportions of missing outcome data or differences in reasons for missing outcome data. The reported reasons for study non‐completion (and therefore missingness) are suggestive that missingness in the outcome depends on the true value of the outcome. Taken together, it is likely that missingness depended on its true value.
Bias in measurement of the outcome (ROB2, primary outcome)   All outcomes	Low risk	Outcome measured using objective CPAP usage data. Authors reference that phone reports were compared against objective CPAP usage data, "Discrepancies we found between compliance reported during weekly phone calls and compliance measured by built‐in counters." Each intervention group outcome data ascertained via automated CPAP device monitoring. Authors report that device makes were sufficiently similar (i.e. similar distributions of CPAP device make) across groups. Outcome "assessor" is CPAP device: no knowledge of allocation possible. However, participants reported these counter values by phone, which does introduce the possibility of false reporting.
Bias in selection of the reported result (ROB2, primary outcome)   All outcomes	Unclear risk	No protocol, abstract, clinical trials entry available for comparison. Results presented were in accordance with the plan specified in the Methods section of the publication. No information as to whether analysis plan was finalised before unblinded outcome data were available for analysis. Methods section indicates one outcome time point (range 1‐2 months) was planned. Results section reports one outcome time point. No evidence that multiple analyses (e.g. variable adherence 'thresholds') were conducted. No threshold‐based adherence outcomes reported.
Overall risk of bias (ROB2, primary outcome)   Machine usage	High risk	‐

Methods	Randomised parallel‐group study. Methods of randomisation not reported
Participants	N = 30 patients being started on CPAP for OSAS. Inclusion criteria: starting nasal CPAP therapy; > 18 years; English‐speaking; AHI > 15 Exclusion criteria: prior CPAP use. Baseline characteristics: Mean age 46. Mean BMI 38. Mean AHI 40. Functional Outcomes of Sleep Questionnaire: TLC: 15.3, Control: 13.8 Country: USA
Interventions	Participants were randomised to telephone‐linked communications technology (TLC, n = 15) versus usual care (UC, n = 15). UC: Described as usual medical care, patient education and demonstration of equipment use. TLC: UC plus computerised digitised human speech programme. TLC asks questions designed to elicit information from participant regarding adherence, education and reinforcement. Study duration: 8 weeks
Outcomes	CPAP usage (hours/night) at 2 months Sleep symptoms QoL (FOSQ) Number of calls per participant
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised; other information not available
Allocation concealment (selection bias)	Unclear risk	Information not available
Blinding (performance bias and detection bias)   All outcomes	High risk	Participants aware of treatment group assignment Intervention involved communication regarding participant's CPAP machine usage
Incomplete outcome data (attrition bias)   All outcomes	Low risk	All completed
Selective reporting (reporting bias)	Unclear risk	Information not available
Other bias	Unclear risk	Information not available
Bias arising from the randomisation process (ROB2, primary outcome)	Unclear risk	Only information provided as to the randomisation procedures used was within Methods: "At the conclusion of a baseline examination (see the description of study measures subsequently), eligible participants were randomised to either TLC and usual medical care or usual medical care alone....A total of 30 participants were enrolled (15 in each group). All participants completed a 2‐month follow‐up evaluation." No reference to random component or allocation concealment method. Key baseline characteristics (age, BMI, AHI) were reported for all randomised participants and differences were non significant (P values reported), consistent with chance. Gender was not reported, but study appears to have taken place at a VA medical centre in early 2000s, which suggests strong possibility that all participants were male.
Bias due to deviations from intended interventions (ROB2, primary outcome)	Low risk	No reference to blinding. No deviations documented; none suspected based upon review. Authors report that all participants completed 2‐month follow‐up evaluation and did not report any dropouts, withdrawals, or loss‐to‐follow‐up. Ns not provided for outcome tables, but available information suggests ITT or mITT analyses were used.
Bias due to missing outcome data (ROB2, primary outcome)   All outcomes	Low risk	Authors report, "All participants completed a 2‐month follow‐up evaluation."
Bias in measurement of the outcome (ROB2, primary outcome)   All outcomes	Unclear risk	Outcome measured using objective CPAP usage data. Each intervention group outcome data ascertained via automated CPAP device monitoring. Unable to confirm with study author that distribution of CPAP device makes did not differ between intervention arms. Outcome "assessor" is CPAP device: no knowledge of allocation possible.
Bias in selection of the reported result (ROB2, primary outcome)   All outcomes	High risk	No protocol, abstract, clinical trials entry available for comparison. Results presented were in accordance with the plan specified in the Methods section of the publication. No information as to whether analysis plan was finalised before unblinded outcome data were available for analysis. Methods section indicates one outcome time point was planned. Results section reports one outcome time point. However, the authors suggest (in results) that the trial may have been longer in the following statement: "The 15 patients in the TLC‐CPAP group participated in the trial for a mean of 9.2 weeks." No evidence that multiple analyses (e.g. variable adherence 'thresholds') were conducted. No threshold‐based adherence outcomes reported.
Overall risk of bias (ROB2, primary outcome)   Machine usage	High risk	‐