How to Interpret the Results of Clinical Trials
The Value of Common Sense
Randomized controlled trials are considered the gold standard for objectively evaluating most treatment strategies, but Dr. Loder cautioned that this design by itself is not enough to ensure reproducible results. The results of the study should include not only how many patients were randomized, but also how many patients received treatment and how many were followed to the trial’s end. Low enrollment or high dropout rates are red flags. These problems can be detected by critical thinking.
“There really is no substitute for common sense,” Dr. Loder said. She suggested that studies that include all of the standard points of discussion, such as the generalizability of results, the limitations of the design, the statistical significance of the findings, and a fair interpretation of benefits and hazards, establish credibility and are generally recognizable with a discerning eye.
“For clinicians considering how to interpret results, one question to ask is whether the patients enrolled are representative of the ones that are in front of you,” Dr. Loder suggested.
A critical view of new data helps to avoid the fads that some critics have observed in the treatment of headaches and in clinical medicine overall. Typically, excessive enthusiasm about positive trial results is followed by a period of disillusionment until clinicians finally arrive at a realistic perspective of the strengths and weaknesses of a new therapeutic option. Warning of a coming brace of headache trial results, which will include studies of devices, apps, and new drugs, Dr. Loder urged clinicians to read the studies rather than the press releases, applying the criteria that define a well designed and fairly reported trial.
—Theodore Bosworth
Suggested Reading
Tfelt-Hansen P, Pascual J, Ramadan N, et al. Guidelines for controlled trials of drugs in migraine: third edition. A guide for investigators. Cephalalgia. 2012;32(1):6-38.
Yavchitz A, Boutron I, Bafeta A, et al. Misrepresentation of randomized controlled trials in press releases and news coverage: a cohort study. PLoS Med. 2012;9(9):e1001308.
