Geospatial analysis of associations among mental health need, housing need, and involuntary psychiatric hospitalizations of people experiencing homelessness in Los Angeles County

The purpose of this study was to use geospatial indicators of mental health need and homelessness in Los Angeles County Service Planning Areas (SPAs) and a psychiatric sample of adults who were homeless to investigate 1) overlap between SPA level of mental health need and corresponding volume of involuntary psychiatric hospitalizations over time; 2) overlap between SPA level of unsheltered homelessness and corresponding volume of involuntary psychiatric hospitalizations over time; and 3) associations between SPA level of mental health need, SPA level of unsheltered homelessness, and initiation of a mental health conservatorship for grave disability. A sample of 373 adults who were homeless and hospitalized on an involuntary psychiatric hold from 2016 to 2018 were linked to data from the Greater Los Angeles Homeless Count on unsheltered homelessness and from the California Health Interview Survey on need for mental health services and suicidality, using admission zip codes to link variables at the SPA level. Geospatial mapping and bivariate tests were used to examine geographic overlap of SPA mental health need and unsheltered homelessness with volume of involuntary psychiatric admissions over the study period. Multiple logistic regression modeling was used to examine associations of SPA mental health need and unsheltered homelessness with conservatorship initiation. The volume of patients admitted from SPAs with higher levels of mental illness need grew from 2016 to 2018 (Tau = 0.27, P < 0.001; Tau = 0.40, P < 0.001), but there were fewer patients admitted from SPAs with higher levels of unsheltered homelessness over the same years (Tau of −0.33, P < 0.001). Being admitted from SPAs with the highest levels of unsheltered homelessness was associated with higher odds of conservatorship initiation (OR = 1.73, 95% CI = 1.82–16.74). Results suggest a need for targeted mental health and housing services to reach areas of highest need in Los Angeles County.