False impression of objectivity may deny patients affordable treatment

Editor—In their review of the clinical impact of obstructive sleep apnoea and the utility of treatment with nasal continuous positive airways pressure John Wright and colleagues make some important points but give a false impression of objectivity.1

Their criteria for excluding abstracts and letters are vague, and the predetermined validity criteria for papers were not well defined—disagreements between the two assessors had to be resolved by a third person. There is evidence of bias, particularly in the discussion on mortality. Two studies in which the design would be unlikely to show any effect are highlighted as showing no significant association between obstructive sleep apnoea and premature death2 3; another in which the apnoea index was a predictor of excess mortality4 is only briefly mentioned and is qualified by the negative statements that the duration of apnoea was not a predictor of mortality and that the excess deaths were not due to heart or lung causes. The important point that the apnoea index was a predictor of premature death was not discussed.

The concept that obstructive sleep apnoea varies from being normal to a life threatening condition is unacknowledged. Results of studies in which most of the patients had only mild disease were used to suggest that there is no link between obstructive sleep apnoea and medical problems. Similarly the authors seem unaware of current medical practice when they state that continuous positive airways pressure is the recommended initial treatment for obstructive sleep apnoea; simple measures such as weight loss are usually tried first.

We are also concerned by the accuracy of the review. There are three errors in the description of our study on nasal continuous positive airways pressure and obstructive sleep apnoea.5 In table 4 of John Wright and colleagues' paper1 the desaturation …