Healthcare Mistrust, Stigma, and Reported Influences on Substance Use among Adults Experiencing Homelessness in Downtown Manhattan: A Convergent Mixed-Methods Pilot Study

<title>Abstract</title> <p> <bold>Background</bold> : People experiencing homelessness face elevated overdose risk and unmet healthcare needs, yet surveillance often emphasizes deaths over survivor perspectives. This project characterized healthcare experiences, reported influences on substance use, overdose history, and unmet needs among unhoused adults in Downtown Manhattan. <bold>Methods</bold> : From July 7-24, 2024, one interviewer recruited 18 adults by convenience sampling along 14 ^th Street between 1 ^st and 6 ^th avenues, and around Union Square Park. Interviews lasting 20-30 minutes were documented in handwritten field notes without audio recording. Two analysts independently coded records and reconciled discrepancies. Open-ended accessibility responses were standardized to an ordinal 1-5 score. Descriptive statistics, Spearman correlation, and a two-sided Fisher exact test were used for quantitative analysis; quantitative and qualitative findings were integrated during interpretation. <bold>Results</bold> : Fourteen participants were men and four were women; mean age was 44.6 years (n=17), and median homelessness duration was 104 weeks (IQR 24-416; n=17). Mean accessibility was 2.8 (SD 1.4); descriptive means were 2.5 among Black participants (n=10), 3.0 among White participants (n=5), and 3.3 among Hispanic participants (n=3). The primary rank correlation was nonsignificant (Spearman rho=-0.23, p=0.373). Fourteen participants reported lifetime substance use. Among 13 with interpretable responses pertaining to factors that subjectively influenced their substance use, 7 described social/interpersonal factors, 6 trauma-related or other early-life experiences, and 1 medical event; categories overlapped. Seven participants (38.9%) had a lifetime overdose history. Mental health or addiction was named unprompted as a current challenge by 4 of 7 participants with a lifetime overdose history (57.1%), compared with 1 of 11 participants without an overdose history (9.1%; two-sided Fisher exact p=0.047). This post hoc comparison was considered hypothesis-generating. Qualitative themes included perceived systemic neglect, institutional mistrust, and stigma or structural exclusion. Housing assistance was the most frequently requested resource (6/18, 33.3%). <bold>Conclusions</bold> : This pilot study identifies relational and structural barriers not captured by mortality data and exploratory associations involving overdose history and perceived accessibility. Larger studies should evaluate survivor-centered, trauma-informed, low-barrier outreach integrated with housing support and accessible resource-navigation tools. </p>