| Methods |
Randomised, parallel, controlled study |
| Participants |
23 people with COPD randomised; FEV1 0.86 L, PaCO2 44.2 mmHg. Raw data 17 people with COPD, FEV1 0.88 L, PaCO2 43 mmHg |
| Interventions |
11 people received standard medical therapy plus nocturnal‐NIPPV (IPAP 16, EPAP 4) for 3 months while 12 people received standard medical therapy plus sham NIPPV |
| Outcomes |
After 3 months: BGA, lung function and 6MWD |
| Notes |
Funding: this project is supported by Canadian Institutes of Health Research (clinical trials), The Institute of Health Economics, and the University of Alberta Hospital Foundation |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Quote: "Recruited patients were randomly assigned to..." |
| Allocation concealment (selection bias) |
Low risk |
Quote: "Randomization occurred at a central site by one individual who was unaware of patients' clinical status" |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
Double‐blind design. Participants were blind to intervention treatment (NIPPV versus sham) and: "All outcome measurements were performed and interpreted by personnel who were blinded to treatment allocation of patients" |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Quote: "Two out of eleven subjects refused any nocturnal therapy following randomisation and were excluded from the main analysis" |
| Selective reporting (reporting bias) |
Unclear risk |
All outcomes listed in the Methods were reported |
| Other bias |
Unclear risk |
At baseline no significant differences except for FEV1, which was significantly higher in the group that received NIPPV |
