Fox 2012.
| Methods | Randomised parallel‐group study | |
| Participants |
N = 75 adults with moderate‐severe OSA by PSG. Inclusion criteria: adult (≥ 19 years), moderate to severe OSA (AHI ≥ 15) Exclusion criteria: active cardiopulmonary or psychiatric disease, previously treated for OSA, no access to telephone line in bedroom, not able to return for follow‐up Baseline characteristics: 20.1% female. Mean age 53.5 (±11.2). Mean AHI 41.6. ESS 9.8.BMI 32.4. Country: Canada |
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| Interventions | Participants were randomised to telemedicine intervention (TM, n = 39) or standard care (SC, n = 36). TM: physiological data (PAP adherence, applied PAP, mask leak, residual respiratory events) were downloaded using modem attached to the PAP device and sent across the telephone line each morning. Downloaded information was reviewed every weekday except holidays by the research co‐ordinator, who contacted the participant if poor compliance or other problems with treatment (e.g. mask leak) were detected. Participants were advised over the phone or visited the PAP co‐ordinator. Standard care identical to control group SC: 20‐minute orientation to PAP session and mask fitting. Participants contacted after two days to check adherence and to troubleshoot problems, followed up at four to six weeks and at three months; each time, physiological data downloaded from machines and any problems with treatment addressed. In addition, data downloaded at eight weeks Study duration: 12 weeks |
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| Outcomes |
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| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "...sequential numbered envelopes" |
| Allocation concealment (selection bias) | Unclear risk | Envelopes were prepared by one of the study investigators |
| Blinding (performance bias and detection bias) All outcomes | High risk | No blinding undertaken Intervention involved communication regarding participant's CPAP machine usage |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | 'intention to treat approach', high discontinuation rate (control group: 10/36, telemedicine group: 11/39) |
| 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: "Patients were randomised to either standard care or telemedicine (1:1 ratio) using sequential numbered envelopes prepared by one of the authors (JW)."
No reference to random component. Allocation concealment method description inadequate for definitive determination. Key baseline characteristics (age, BMI, AHI) were reported for all randomised participants and differences were reported as non‐significant (P values not presented). Statistical comparison of gender proportions (77.8% vs. 82.0% male in control vs. intervention arms) was not reported. |
| Bias due to deviations from intended interventions (ROB2, primary outcome) | Low risk | Unblinded. No deviations documented; none suspected based upon review. Probable mITT. Authors report 'using an intention‐to‐treat approach,' but it is not clear how participants who 'Discontinued CPAP' (Figure 1) were handled (i.e. whether excluded from outcome calculations, as in mITT, or counted as non‐adherent and counted as having 0 minutes/night.) |
| Bias due to missing outcome data (ROB2, primary outcome) All outcomes | Low risk | Although the authors do not state so explicitly, it seems likely that outcome data were available for all participants, As noted in Methods, "Identical to the standard pathway, all patients were oriented to CPAP, fitted with a mask, and given an auto titrating machine. A modem was attached to the PAP device EncoreAnywhere®, Philips Respironics Inc.)..." Thus, those participants who 'Discontinued CPAP' as per Flow Figure 1, probably did not have missing data but had 0 minutes/night. |
| 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 | Low risk | ClinicalTrials.gov entry (NCT00561860) indicates that the original primary outcome measures were the same as the current primary outcome measures, "CPAP compliance (3 months) and overall cost of patient care [ Time Frame: 3 months ]" (submitted 20nov2007). Final data collection date for primary outcome was Sep 2010. Publication year 2012. NCT outcome is the same as that presented in published report. Likely that analysis plan finalised before unblinded outcome data available for analysis. Methods section indicates one outcome time point (for primary adherence outcome) 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 | Unclear risk | ‐ |