Attitudes About Clinical Trials of Medications in Older Hispanic/Latino Adults With Multimorbidity

Hispanic/Latino individuals represent a rapidly growing segment of the US population, yet older Hispanic/Latino adults remain underrepresented in clinical trials of new medications [1, 2]. Since people of different ages, races, or ethnicities may respond differently to therapeutic agents [3-5], this gap raises concerns about medication efficacy and safety. This study explores barriers and facilitators of clinical trial participation among older Hispanic/Latino adults with multiple chronic conditions.

We conducted focus groups between February and September 2023 with adults aged 65 years and older who self-identified as Hispanic/Latino of Mexican origin and reported taking five or more prescription medications. Participants were recruited from senior centers in Los Angeles and San Francisco through information sessions and flyers and from UCLA and UCSF through electronic health record data extractions and email invitations. Respondents were sampled based on their preferred language (English or Spanish) and previous participation in research studies (Supporting Information Figure S1).

Focus groups were conducted in person or via Zoom, moderated by a Spanish-English bilingual researcher using a semi-structured guide to investigate participants' perspectives of clinical trial participation. Participants received compensation for their participation. Focus groups were analyzed in ATLAS.ti 23 using thematic analysis [6]. Theoretical saturation [7] was achieved. The UCSF Institutional Review Board (IRB) approved the study protocol.

We conducted 14 focus groups with 93 participants (Table 1): nine with 61 participants without previous research experience and five with 32 participants with previous research experience, including 7 who had participated in clinical trials. The mean age was 72.1 years (SD = 5.4); 55 (59.1%) were female, and 51 (54.8%) opted for Spanish-speaking groups. See Supporting Information Tables S1 and S2 for additional participant characteristics. We identified major themes concerning clinical trial participation (Table 2).

Our findings reveal key barriers to clinical trial participation among older Hispanic/Latino adults. While participants expressed general concerns about medication safety and logistical burdens, limited awareness and culturally specific barriers—especially mistrust—were particularly prominent. To build trust, involving physicians and family members in recruitment may be critical, as both were identified as influential in enrollment decisions.

Our results align with existing recommendations of providing linguistically and culturally appropriate engagement to enhance clinical trial participation among ethnic minority groups [5, 9, 10]. However, participants also emphasized within-group diversity, including Spanish dialects, country of origin, and generational differences, which should be considered when developing interventions.

This study has limitations. Participants were recruited from the West Coast, which may not reflect nationwide perspectives. The reported number of chronic conditions may not fully capture participants' health status since they were selected from a nonexhaustive list. Ten participants took fewer medications than the inclusion criteria, though their views were consistent with others.

Understanding the preferences of older Hispanic/Latino adults is essential for improving clinical trial enrollment. This study identifies barriers specific to older Hispanic/Latino adults of Mexican origin. Additional research is needed to determine the generalizability of these findings across the broader Hispanic/Latino population and other minority communities.

Study concept and design: Janice B. Schwartz and Derjung M. Tarn. Data collection, data analysis, and preparation of manuscript: Ruey-Ying Liu, Janice B. Schwartz, Bruno Renero-Hannan, Irene Del Mastro N., and Derjung M. Tarn.

Dr. Schwartz and Dr. Tarn have previously been funded for unrelated research by investigator-initiated research awards from Bristol-Myers Squibb and Pfizer, as part of the American Thrombosis Investigator Initiated Research Program (ARISTA-USA).