2.2. Study screening and recruitment

The outreach and recruitment approach was developed and implemented in collaboration with the local Administration on Aging (AoA) and a network of AoA-supported community centers (Department of Aging and Adult Services or DAAS of San Francisco County). DAAS supports a large network of senior centers throughout San Francisco and serves older adults from diverse racial/ethnic and SES backgrounds. We recruited adults aged 60 and older from each of the 12 senior centers. The sampling frame included persons already attending each senior center and those within each of the senior center's geographic service area. Similar to our previous work recruiting ethnically diverse, lower-SES adults [16], [19], we used multiple methods (e.g., flyers, presentations, word-of-mouth, and radio) shared with the senior centers and local community organizations, utilized a research team that reflected the diversity of the community (including bilingual and bicultural research associates), and completed all recruitment and screening assessment procedures in the ecommunity at each of the senior centers. The research team spent three months (2–3 days per week) on-site at each senior center to answer questions about the study and complete the screening and enrollment process. The research team passed out flyers and answered questions during events at the senior centers (e.g., food tabling, ongoing classes) and shared information with organizations (e.g., senior housing, libraries) in the geographic service area of each senior center. The study protocol, consent forms, and outcome measures were approved by the Institutional Review Board at the University of California, San Francisco.

Through these outreach methods, interested individuals were invited to attend an informational meeting about the study at the senior centers or to provide their name and phone number to be called by a staff person to discuss the study over the phone. The choir intervention content, duration, study procedures, risks, and randomization procedures were explained in English or Spanish, and questions were answered. For those who attended an informational meeting and expressed interest in the study, a screening assessment was done in person. For those reached by phone, screening began on the phone using the identical screening script used for the in-person screening assessments except that the cognitive screen was done in-person during the start of the baseline assessment because it required responses on paper.