. 2019 May 1;2019(5):CD010990. doi: 10.1002/14651858.CD010990.pub2

Summary of findings for the main comparison. Positional therapy compared to continuous positive airway pressure (CPAP) for obstructive sleep apnoea.

Positional therapy compared to continuous positive airway pressure (CPAP) for obstructive sleep apnoea
Patient or population: adults with obstructive sleep apnoea  Setting: interventions used at home  Intervention: positional therapy  Comparison: CPAP
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	No. of participants  (RCTs)	Certainty of the evidence  (GRADE)	Comments
Outcomes	Risk with CPAP	Risk with positional therapy	Relative effect  (95% CI)	No. of participants  (RCTs)	Certainty of the evidence  (GRADE)	Comments
Epworth Sleepiness Scale (ESS) Follow‐up: 1 month	The mean ESS was 10.4	MD 1.2 higher  (1.91 lower to 4.31 higher)	‐	20  (1 RCT)	⊕⊕⊝⊝  Low^a,b	Skinner 2008 was a home‐based study of single nights after 1 month of use in a cross‐over design. Lower ESS scores are better. MCID is estimated to be a fall of 2‐3 points
Apnoea‐Hypopnoea Index (AHI) Follow‐up: 2 weeks to 1 month	The mean AHI ranged from 3.4‐4.9	MD 6.4 higher  (3 higher to 9.79 higher)	‐	33  (2 RCT)	⊕⊕⊝⊝  Low^c,d	Skinner 2008 was a home‐based study of single nights after 1 month of use in a cross‐over design. Jokic 1999 used overnight laboratory‐based PSG after 2 weeks in a cross‐over design. Lower AHI is better. MCID is considered as 5 events/ hour
Self‐reported adherence time Follow‐up: 1 month	The mean self‐reported adherence time was 4.9 hours/night	MD 2.5 hours/night higher  (1.41 higher to 3.59 higher)	‐	20  (1 RCT)	⊕⊕⊕⊝  Moderate^a	Skinner 2008 was a home‐based study of single nights after 1 month of use in a cross‐over design. MCID is not established.
Adverse effects Follow‐up: 1 month	Skinner 2008 was a home‐based study of single nights after 1 month of use in a cross‐over design. They used the aggregate score of 19 self‐report questions graded as 0, no effect; 1, mild effect but did not disturb sleep; 2, sleep disturbed; 3, could not use device for assessing adverse events. They reported that this aggregate score was less for positional device compared to CPAP (MD: 3.6; 95% CI 3.4 to 5.8).			20 (1 RCT)	GRADE not applied	No details of the questionnaire are available to understand the nature of adverse events sought.
Quality of life Assessed using SF‐36 or FOSQ Follow‐up:1 month	SF‐36 physical: mean 44.6 SF‐36 mental mean: 49.7 FOSQ mean: 12.8	MD for SF‐36 physical 0.10 lower (6.79 lower to 6.59 higher); MD for SF‐36 mental was 0.60 higher (4.99 lower to 6.19 higher); MD for FOSQ was 0.40 lower (1.82 lower to 1.02 higher)		20 (1 RCT)	⊕⊕⊝⊝  Low^a,e	Skinner 2008 was a home‐based study of single nights after 1 month of use in a cross‐over design. They reported SF‐36 and FOSQ. There were no differences in either score between the groups.
Sleep quality Assessed by average duration of slow‐wave and REM sleep periods Follow‐up: 2 weeks	Mean % of REM sleep: 26%; Mean % of slow wave sleep: 22% Mean sleep efficiency: 84%	MD for % of REM sleep was 2% lower (8.22% lower to 4.22% higher); MD for % of slow‐wave sleep was 2% lower (9.12 lower to 5.12 higher); MD for sleep efficiency was 2% lower (8.4% lower to 5.4% higher)		13 (1 RCT)	⊕⊕⊝⊝  Low^a,e	Jokic 1999 used overnight laboratory‐based PSG after 2 weeks in a cross‐over design. They reported on proportion of sleep time spent in REM phase, in slow‐wave phase and also on sleep efficiency (total sleep time/total record time). They did not note any significant difference between positional therapy and CPAP.
Cognitive dysfunction Follow‐up: 1 month	Jokic 1999 used overnight laboratory‐based PSG after 2 weeks in a cross‐over design. They studied cognitive outcomes using 6 tests with 34 subtests and noted no difference between the groups.			13 (1 RCT)	GRADE not applied	The outcomes carry issues related to multiple comparisons.
*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 airway pressure; FOSQ: Functional Outcomes Sleep Questionnaire; MCID: minimal clinically important difference; MD: mean difference; OR: odds ratio; PSG: polysomnography; RCT: randomised controlled trial; REM: rapid eye movement; RR: risk ratio; SF‐36: short‐form 36
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.

^aMethods employed for randomisation and allocation concealment not explicitly stated in the study. Participant blinding not done. Downgraded for risk of bias.  ^bThe confidence interval of the estimate is imprecise. Downgraded for imprecision.  ^cNeither study mentioned the methods employed for randomisation and allocation concealment. Both had unblinded participants. Only one study reported outcome assessor blinding. Downgraded for risk of bias.  ^dJokic 1999 used laboratory‐based polysomnography, while Skinner 2008 used home‐based monitors with reported kappa for agreement of 0.6 with polysomnography. Downgraded for imprecision of measuring techniques.  ^eThe confidence interval of the estimate is imprecise. Downgraded for imprecision.