Recruitment Challenges for Low-Risk Health System Intervention Trials in Older Adults: A Case Study

Objective: To assess factors associated with trial participation in the context of a low-risk intervention intended to reduce adverse drug events in recently hospitalized older adults.

Design: Mixed methods: analysis of data collected during enrollment efforts and focus groups.

Setting: A large, multispecialty group practice.

Participants: Individuals 50 years and older, recently discharged from the hospital and prescribed at least one high-risk medication, were eligible for the trial. Enrollees, decliners, and their caregivers were eligible to participate in focus groups.

Measurements: Reasons for declining to participate during the initial invitation as well as reasons for not providing consent were recorded. Focus groups were conducted with eligible individuals to explore reasons for enrolling or declining. We conducted multivariable logistic regression to compare characteristics (including sex, age, healthcare proxy, number and type of medications, visiting nurse services, reason for admission, and length of hospital stay) of those who enrolled with those who did not enroll.

Results: Of 3,606 individuals determined eligible, 3,147 (87%) declined, 98 (3%) verbally consented to participate but did not complete written consent, and 361 (10%) provided written consent and were considered enrolled. Individuals 80 year and older (odds ratio (OR) = 0.44; 95% confidence interval (CI) = 0.30-0.65) and those with visiting nurse services (OR = 0.64; 95% CI = 0.48-0.85) were least likely to enroll. Among those who provided a reason for declining (2,473), the most common was the belief they did not need additional medication assistance (18%). Another 332 (11%) declined because they were receiving visiting nurse services.

Conclusion: Recruiting older adults recently discharged from the hospital to participate in trials of low-risk, system-level interventions is challenging and may underenroll the oldest individuals and those potentially at the highest risk for adverse events, limiting generalizability of study findings. Alternative study designs may be more effective than individually randomized trials in assessing low-risk, system-level interventions.