Exclusion of Elderly People from Randomized Clinical Trials of Drugs for Ischemic Heart Disease

Objectives: To measure exclusion of elderly adults from randomized trials studying drug interventions for ischemic heart disease (IHD) and describe the characteristics of these trials. Design: Cross-sectional analysis. Setting: Interventional clinical trials studying a drug intervention for IHD that started in 2006 and after were identified in ClinicalTrials.gov. Data were extracted on study features, including age-based inclusion criteria. Data on participants and their age distribution were collected from trial publications, investigator inquiry, and result data in ClinicalTrials.gov. Participants: Individuals aged 65 and older. Measurements: Proportion of trials excluding individuals based on age, mean age of trial participants, and proportion of enrolled participants aged 65 and older and 75 and older. Results: Of 839 identified trials, 446 (53%) explicitly excluded elderly adults. The most-frequent upper age limits were 80 (n = 164) and 75 (n = 114), with a median upper age limit of 80 (interquartile range 75–80). Trials with upper age limit exclusions tended to be smaller (median number of participants 100 vs 201, P <.001) and were more likely to be funded primarily by nonindustry sources (78.3% vs 70.0%, P =.006). The overall mean age of trial participants was 62.7 (mean maximum age 74). The estimated proportion of participants aged 65 and older was 42.5% and the estimated proportion aged 75 and older was 12.3%. Conclusion: Despite the high burden of IHD in elderly adults, the majority of drug trials do not enroll participants reflective of age-related prevalence of the disease.