The application of GIS in homelessness research and service delivery: A qualitative systematic review

Predicting hotspots of unsheltered homelessness using geospatial administrative data and volunteered geographic information

Unsheltered homelessness is an increasingly prevalent phenomenon in major cities that is associated with adverse health and mortality outcomes. This creates a need for spatial estimates of population denominators for resource allocation and epidemiological studies. Gaps in the timeliness, coverage, and spatial specificity of official Point-in-Time Counts of unsheltered homelessness suggest a role for geospatial data from alternative sources to provide interim, neighborhood-level estimates of counts and trends. We use citizen-generated data from homeless-related 311 requests, provider-based administrative data from homeless street outreach cases, and expert reports of unsheltered count to predict count and emerging hotspots of unsheltered homelessness in census tracts across the City of Los Angeles for 2019 and 2020. Our study shows that alternative data sources can contribute timely insights into the state of unsheltered homelessness throughout the year and inform the delivery of interventions to this vulnerable population.

Does the Relationship between Affect and Social Interactions among Adults Experiencing Homelessness Differ during Moments when at a Shelter versus Not?

The prevalence of alcohol use disorders is higher amongst adults experiencing homelessness (AEH) compared with domiciled adults. Greater exposure to heavy drinkers increases personal risk for heavy alcohol use. AEH spend substantial periods of time at shelters and report greater pressure to use alcohol when near shelter locations, as well as greater negative affect when near a shelter. It is unclear if the relationship between affect and 1) interacting with people and 2) being near someone AEH drank alcohol with before differs when AEH are at a shelter versus not. AEH reporting alcohol misuse (n = 72, Mage= 47, 85% Male, 68% Non-White) completed five daily smartphone-based ecological momentary assessments (EMAs) over 28 days. Generalized multilevel modeling revealed that when AEH were interacting with someone they drank with before, they had significantly lower positive affect when at a shelter (b = -0.17, p = 0.05), versus when not (b = 0.00, p = 0.99). AEH are likely to interact with previous drinking partners while at shelters. It may be important to deliver real-time treatment messages targeting affect in these moments, as well as deliver alcohol reduction/abstinence messages.

Improving longitudinal research in geospatial health: An agenda

All aspects of public health research require longitudinal analyses to fully capture the dynamics of outcomes and risk factors such as ageing, human mobility, non-communicable diseases (NCDs), climate change, and endemic, emerging, and re-emerging infectious diseases. Studies in geospatial health are often limited to spatial and temporal cross sections. This generates uncertainty in the exposures and behavior of study populations. We discuss a research agenda, including key challenges and opportunities of working with longitudinal geospatial health data. Examples include accounting for residential and human mobility, recruiting new birth cohorts, geoimputation, international and interdisciplinary collaborations, spatial lifecourse studies, and qualitative and mixed-methods approaches.