Commentary: We still need observational studies of drugs—they just need to be better

Abstract
The paper by de Vries and colleagues examined different observational study designs used to assess the effects of statin use and demonstrates three key points. First, the need for accurate matching on key prognostic variables—in this case age. Second, the need to consider the underlying biology when designing epidemiological studies. Third, they suggest that a case–control study nested within a selected group of people may be more prone to bias than a population-based study. However there may be a bigger issue: both the observational designs found a substantial protective effect, while robust data from randomized trials suggests there is no effect. Does this mean we should do away with observational studies of drugs?