Randomized Trials or Observational Tribulations?

The role of observational studies in the evaluation of treatments is a long-standing and contentious topic.1 In this issue of the Journal, Concato et al.2 and Benson and Hartz3 report that observational studies give results similar to those of randomized, controlled trials. If these claims lead to more observational studies of therapeutic interventions and fewer randomized, controlled trials, we see considerable dangers to clinical research and even to the well-being of patients.Any systematic review of evidence on a therapeutic topic needs to take into account the quality of the evidence. Any study, whether randomized or observational, may have flaws . . .