Smith 2006.

Methods	Randomised parallel‐group trial
Participants	N = 19 with newly‐diagnosed OSA, non‐adherent with CPAP for 3 months Inclusion criteria: new OSA diagnosis, first CPAP prescription, received initial education on CPAP use and supplemental audiotaped/videotaped reinforcement at two and four weeks, non‐adherent with CPAP for 3 months Exclusion criteria (unclear if a priori): positive screen for drug or alcohol abuse, depression requiring hospitalisation Baseline characteristics: % female NR. Mean age 63 (± 8). Mean AHI NR. Mean ESS NR. Mean BMI NR. Country: USA
Interventions	Participants were randomised to control (n = 9) or intervention (n = 10) group. Intervention:two‐way telehealth sessions mediated by video link‐up through phone line. Research nurse emphasised nightly, bedtime routine for CPAP. After standardised protocols, nurse visually assessed participant, guided correct CPAP routine and determined whether the CPAP mask fits properly. Nurse described consequences of non‐adherence and managing barriers to CPAP use. Benefits of nightly CPAP use for general health were emphasised Control: two‐way telehealth sessions mediated by video link‐up through phone line. Protocols drawn up to mimic content delivered to intervention group. Instead of CPAP‐related information, participants given content on vitamin intake Study duration: 12 weeks
Outcomes	N of adherent participants (usage ≥ 4 hours/night on ≥ 9 of 14 nights) at 12 weeks Participant satisfaction Withdrawal
Notes	Non‐adherence in the study defined as less than four hours of CPAP use per night for fewer than nine of 14 consecutive nights' use TJL emailed for details of randomisation and outcome data 12 September 2008. Carol Smith responded 15 September 2008. For updated review, further email communication was required to verify that updated inclusion criteria were met, confirmation received from Carol Smith, 27 March 2019.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"...randomised and done via computer software generated random assignment"
Allocation concealment (selection bias)	Low risk	"...allocation sequence and treatment group assignment concealed from investigators conducting the screening and ongoing assessments"
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Single‐blind; nursing interventionist staff aware of different content delivered by video link‐up Machine usage was measured via smart card by blinded sleep lab personnel. Information on participants' awareness of CPAP machine usage was insufficient for us to determine how this might have affected the study
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants finished follow‐up and contributed to data on adherence. Two satisfaction surveys were not submitted (one from each group)
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: "After the University of Kansas Medical Center's Institutional Review Board approval, the random assignment process began." No reference to random component or allocation concealment method. Regarding baseline characteristics, the authors provided no table. They reported, "Group 1 and group 2 were compared using two group t test statistics to assure there were no between‐group differences. Mean ages of the two groups did not differ. Patient ages ranged from 50 to 83, with a mean of 63 +/‐ 7.95. All patients' respiratory distress index (RDI) scores were all in the severe range with scores not differing significantly between groups 1 and 2 (t test = 0.737, P = 0.471). These results indicate there was no significant difference between group 1 and group 2 on age or severity of sleep apnoea. Thus, age or severity of sleep apnoea did not influence outcomes of adherence." Thus, authors report that differences in age and baseline OSA severity are consistent with chance. However, they do not report (and may not have evaluated) baseline differences in gender or BMI. There was no information on some potentially influential baseline characteristics. Given the date of the publication and the author affiliation with a VA hospital, as well as the small N, Review authors suspect this study was conducted on all male participants.
Bias due to deviations from intended interventions (ROB2, primary outcome)	Low risk	No deviations documented; none suspected based upon review. Outcome based on all randomised participants based on denominators used for calculation of proportions adherent, "A higher percentage of group 1 than group 2 participants were adhering to CPAP after the telehealth interventions (X2=4.55, P = 0.033). Specifically, 90% (n = 9 of 10) of group 1 compared to 44% (n = 4 of 9) of group 2 participants were adherent after the telehealth sessions."
Bias due to missing outcome data (ROB2, primary outcome) All outcomes	Low risk	Authors report, "...there were only 3 episodes of transmission problems, each easily corrected." This suggests that there were no missing outcome data.
Bias in measurement of the outcome (ROB2, primary outcome) All outcomes	Low risk	The adherence outcome measurement comes from participants' CPAP ventilator timer‐recorder. This is consistent with CPAP technology available at the time of the study. 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 (verified via author correspondence). 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 one outcome time point (for primary adherence outcome) was planned. Results section reports one outcome time point. Methods section indicates that one, commonly‐employed threshold adherence definition was planned; this outcome was reported in Results. No evidence that multiple analyses (e.g. variable adherence 'thresholds') were conducted.
Overall risk of bias (ROB2, primary outcome) Machine usage	Unclear risk	‐