Age-based exclusions in clinical trials: A review and new perspectives

Abstract

Background: Despite elderly populations having a greater risk of being diagnosed with serious medical conditions, there has been limited clinical testing conducted on geriatric patients. By analyzing cancer, cardiovascular diseases, and type 2 diabetes data from ClinicalTrials.gov, we investigate two factors that may have significant impact on the exclusion of elderly patients from clinical trials.

Methods: We examine age exclusion across phases and funder types and demonstrate the extent of these exclusions over all interventional studies that commenced enrollment on or after January 2010 to Oct 2021.

Results: Cancer trials have the lowest percentage of age capped enrollment, with 22.18%, 24.13%, and 32.77% of the studies listing an upper age limit in Phases 1, 2, and 3, respectively. In comparison, cardiovascular disease trials are age capped in 51.32%, 39.9%, and 34.94% of trials, and type 2 diabetes capped in 90.3%, 74.42%, and 36.75% of trials in Phases 1, 2, and 3 respectively. Our result shows no significant changes in the percentage of trials with upper age limits pre- and post- NIH Inclusion Across the Lifespan Policy.

Conclusion: Our analysis reveals cancer trials were the most age-inclusive. Further, NIH-funded trials have historically set fewer age caps compared to those whose funding has come from non-NIH sources, which provides optimism that inclusivity can be feasible for all trials.

Keywords: Age; Clinical trials; Funder type; Inclusion-exclusion; NIH.