Domiciliary NIPPV in COPD

I was surprised to find that the paper by Jones et al 1 did not come up to the normally high standard of the journal. Firstly, the study design itself lacks a control group and yet attempts to make a contribution to the debate about using non-invasive positive pressure ventilation (NIPPV) to improve survival in COPD. Clearly, comparing before and after treatment as a measure of survival can be misleading as it may introduce a “placebo effect” bias that may easily swamp out any physiological improvement. In these days of systematic reviews this evidence is flimsy and may well dilute the effect of good prospective controlled randomised studies. There were a few minor errors in table 1 which, firstly, presents …