Author Affiliations: Institute for Clinical Research and Health Policy Studies, Tufts-New England Medical Center, Boston, Massachusetts (Dr Kent); and Veterans Affairs Ann Arbor Health Services Research and Development Service Center of Excellence and Department of Internal Medicine, University of Michigan, Ann Arbor (Dr Hayward).
There is growing awareness that the results of randomized clinical trials might not apply in a straightforward way to individual patients, even those within the trial. Although randomization theoretically ensures the comparability of treatment groups overall, there remain important differences between individuals in each treatment group that can dramatically affect the likelihood of benefiting from or being harmed by a therapy.1- 4 Averaging effects across such different patients can give misleading results to physicians who care for individual, not average, patients.
Kent DM, Hayward RA. Limitations of Applying Summary Results of Clinical Trials to Individual PatientsThe Need for Risk Stratification. JAMA. 2007;298(10):1209-1212. doi:10.1001/jama.298.10.1209