Assessing geographic disparities in mental health research participation.

Background: Large geographic health disparities are well-documented within the U.S. Although approximately 60 million Americans-or roughly 20% of the total U.S. population-live in rural areas, rural residents may be less likely to participate in health research, including mental health research, due to multiple barriers. This retrospective analysis evaluated the urbanity and rurality of inpatient research participants and potential research participants over a five-year period at the Experimental Therapeutics and Pathophysiology Branch (ETPB), NIMH-NIH (Bethesda, Maryland), which conducts experimental medicine and neurobiological research in mood disorders.

Methods: Participant and potential participant zip codes were converted to Rural Urban Commuting Area (RUCA) codes (1-3 urban, 4-10 rural). These results were compared with each other and with U.S. population data.

Results: The analysis included 182 research participants and 1864 potential research participants; the former were admitted to an in-person research unit and the latter were screened by phone or online. ETPB research participants had an urban residence rate of 93.4% and a rural residence rate of 6.6%. Potential ETPB research participants had an urban residence rate of 90.9% and a rural residence rate of 9.1%. In comparison, the U.S. urban residence rate is 80% and the rural rate is 20%.

Conclusion: At the ETPB, both research participants with mood disorders admitted to an in-person research unit and potential research participants screened online or by phone from rural areas were under-represented relative to participants from more urban areas. Further study of research recruitment barriers in rural areas of the U.S is needed.