As physicians, we take great interest in the adherence of our patients to prescribed medications. This is based on our belief that the benefits of treatment will be greater in patients who take their medication regularly and less among those who do not. C Everett Koop is quoted as having said: “Drugs don’t work in patients who don’t take them”. The practice of faithfully complying with a medication regimen, however, may be just as important as the efficacy of the medication itself. In this month’s issue of Thorax, Vestbo et al1 report that, among patients with chronic obstructive pulmonary disease (COPD) participating in the TORCH trial,2 adherers experienced significantly better survival and a lower risk of hospital admission due to exacerbations than non-adherers (see page 939). These effects, however, were independent of treatment group.

In fact, a growing body of literature suggests that adherence to drug therapy in clinical trials—both medication and placebo regimens—predicts better outcomes. Many of these data have been generated from cardiovascular trials.3 In 1980 a report from the Coronary Drug Project significantly challenged traditional scientific thought regarding the relationship between adherence and disease outcomes.4 This randomised double-blind placebo controlled trial examined the effects of clofibrate on the survival of men who had experienced a myocardial infarction.5 Five-year mortality was similar for those …