| Methods |
Randomised, parallel, controlled study |
| Participants |
144 people with COPD randomised; FEV1 0.59 L, PaCO2 53.5 mmHg. Raw data 81 people with COPD, FEV1 0.65 L, PaCO2 54 mmHg |
| Interventions |
72 people received standard care plus nocturnal‐NIPPV (IPAP 13, EPAP 5) for 24 months and 72 continued optimal standard care |
| Outcomes |
After 12 months: BGA, lung function, sleep studies (total sleep time in only NIPPV group), HRQoL (SGRQ and SF‐36), hospitalisation rates (days on trial:days in hospital rate), survival |
| Notes |
Funding: Australian National Health and Medical Research Council, Air Liquide Healthcare, Australian Lung Foundation |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Quote: "Patients were randomly assigned..." |
| Allocation concealment (selection bias) |
Low risk |
Quote: "The central study coordinator generated a random sequence of treatment assignments that were stratified by centre and distributed in blocks of 10 sealed opaque envelopes to centres" |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
No blinding for participants, intervention or personnel |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Quote: "All primary analyses were conducted on an intention‐to‐treat basis. However, since a proportion of patients assigned to NIV treatment did not use the treatment regularly or abandoned it altogether after a time, a planned per protocol sub analysis was conducted comparing outcomes of patients in the treatment arm who used NIV consistently (defined as average > 4 hours per night) with patients in the control arm" |
| Selective reporting (reporting bias) |
Unclear risk |
All outcomes listed in the Methods were reported |
| Other bias |
Low risk |
The study appears to be free of other source of bias |
