Assessment of feasibility and outcomes of a salivary cortisol collection protocol in five American Indian communities.

We evaluated the feasibility and outcomes of administering a naturalistic saliva collection procedure and assessment in American Indian (Indigenous) communities. We focus on Indigenous adults living with type 2 diabetes given the "epidemic" of the disease disproportionately impacting many tribal groups. Data are from community-based participatory research (CBPR) involving 5 tribal communities. Participants were randomly selected from tribal clinic records. The sample includes 188 adults living with type 2 diabetes (56% female; age range = 18-77 years; M age = 46.3 years). Participants provided a total of 748 saliva samples, representing 4 samples/participant on a single day with instructions for collection at 4 time points: upon waking, 1 h after waking, 2 h after waking, and at 8 PM. Saliva sample times were recorded by participants on paper and electronically via placement in a Medication Event Monitoring System (MEMS®) bottle. Overall, 67% of samples were completed within 10 min of protocol instructions and 91% of participants provided at least one useable sample (79% provided four useable samples). Noncompliance, behavioral and environmental factors were not robustly associated with deviations in observed cortisol indices. Results suggest that home-based, community interviewer-involved protocols yields valid data with high compliance. The success of this study was facilitated by exemplary efforts of tribal community-based interviewers and our overall CBPR approach.Lay summaryAuthentic efforts for tribal community partnerships in research are critical to successfully implementing biological assessments with American Indians given legacies of research misconduct and mistrustOur Community-Based Participatory Research with 5 tribes yielded high participant compliance to a home-based salivary cortisol collection protocolLack of compliance to salivary cortisol protocol and medication usage were not consistently associated with observed cortisol indices.