LAUSR

BACKGROUND Older adults are underrepresented in most clinical trials. As the United States observes growth in the number of older adults over time, it will be critical to include them in clinical trials to improve the generalizability of results across age groups. Although clinical trial participation requires clinical trial knowledge, no study has assessed clinical trial knowledge among older adults. Using a national survey, this study aims to identify the prevalence and determinants of clinical trial knowledge among older adults. METHODS We used the 2020 Health Information National Trends Survey for secondary data analysis. We restricted the sample to older adults (aged 65 years and up). Our outcome variable was whether respondents reported having any clinical trial knowledge. We controlled for demographics, social determinants of health, healthcare utilization, and comorbidities through multivariable logistic regression models. RESULTS Using a weighted sample of 27,574,958 adults, we estimated that 61.1% of older adults reported having at least some knowledge of clinical trials. After controlling for other factors, those with one to two (OR = 1.80, 95% CI:1.14-2.84) or three to five (OR = 2.93, 95% CI:1.74-4.95) portal visits compared with no portal visits, those with cancer (OR = 1.92, 95% CI:1.22-3.02), and those with depression (OR = 2.27, 95% CI:1.23-4.20) had greater odds of having clinical trial knowledge. Inversely, those with hypertension (OR = 0.62, 95% CI:0.42-0.92) had lower odds of clinical trial knowledge. CONCLUSIONS Patient portal recruitment may be a supplemental intervention to improve clinical trial knowledge among older adults. Further research on additional interventions for identifying eligible participants is needed to minimize the burden among clinicians amidst other competing demands during clinic visits.