92 Background: Patient participation in clinical trials (CTs) is vital for knowledge advancement and outcomes improvement. The rate of CT participation for adult cancer patients is between 5%-8%; many CTs fail due to poor accrual. Although patient decision-making is a common focus of studies examining barriers to CT participation, the rate of trial participation for patients actually offered a CT is unknown. Methods: We conducted a systematic review and meta-analysis using PubMed, Web of Science, and Ovid Medline search engines to identify studies over 20 years (1/1/2000-1/1/2020) that examined CT participation. Studies must have been conducted in the United States and specified the number of patients offered a CT and the number enrolled. We conducted a meta-analysis of single proportions using random effects. Rates were examined for both treatment trials and cancer control (CC) studies. We also compared the rates of enrollment between Black, Hispanic, and Asian patients versus White patients. Clinical care setting (academic vs community) was examined as a potential moderator. Results: We screened 3,241 unique citations and identified 35 (30 treatment and 5 CC) studies among which n = 9,759 patients were offered CT participation. Overall, 55.0% (95% CI: 49.4%-60.5%) of patients offered a CT agreed to enroll. Trial participation rates did not differ between treatment (55.0%, 95% CI: 48.9%-60.9%) and CC trials (55.3%, 95% CI: 38.9%-71.1%, p = .98); however, participation rates were significantly higher at academic centers (58.4%, 95% CI: 52.2%-64.5%) versus community centers (45.0%, 95% CI: 34.5%-55.7%, p = .04). In common studies, Black patients agreed to participate at similar rates (58.4%, 95% CI: 46.8%-69.7%) compared to White patients (55.1%, 95% CI: 44.3%-65.6%, p = .88). Results were also similar comparing White versus Hispanic or Asian patients. The main reasons for non-participation were treatment choice or lack of interest. Conclusions: More than half of all cancer patients who are offered CTs do participate; results were consistent between major race/ethnicity groups. This finding upends several conventional beliefs about cancer clinical trial participation, including that Black patients are less likely to agree to participate and that patient decision-making is the primary barrier to participation. Policies and interventions to improve CT participation should focus more on modifiable systemic structural and clinical barriers, such as improving access to existing trials and broadening trial eligibility.
Development and testing of a guideline document to provide essential information for patient decision making regarding cancer clinical trials
