Appropriate representation of specific groups of patients in randomized controlled trials (RCTs) and generalizability of evidence obtained have been questioned. We sought to compare the characteristics of patients in heart failure (HF) RCTs with those of patients with HF in the community, and to document these trends over time.
MEDLINE was searched from 1985 through December 1999 for all HF RCTs. Additional trials were obtained through bibliographies of the reviewed articles, previous meta-analyses, and overviews of the HF trials. Original reports of RCTs of interventions for chronic HF were selected if they were published in the English language and included 50 or more participants. Publication year, sources of support, location of principal investigator, sample size, type of intervention, inclusion and exclusion criteria, characteristics of participants, and the use of invasive diagnostic tests were extracted.
Participants in the 59 HF RCTs we reviewed were markedly different from the patients with HF in the community. Patients in RCTs were younger, more often male, more likely to have subnormal systolic ejection fraction, and were most commonly white. We did not find a significant improvement in the representation of the trials, with respect to these characteristics, among those published recently compared with those from the late 1980s and early 1990s.
Clinical trials are focusing on a relatively small segment of the HF population. The consequences of underrepresenting minorities, women, and elderly are unknown but may be particularly important for HF. Future clinical trials should adequately include populations that carry the burden of the disease.