Bouloukaki 2014.
| 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 |
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| 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 15th and 30th 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 |
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| Outcomes |
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. |
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| 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 | ‐ |