GPS exposure assessment for health equity research and spatial epidemiology

Longitudinal GPS data can enhance the precision of spatial exposure assessment, yet few spatial epidemiologic studies incorporate such data and even fewer do so in the context of health equity. We examined geographic extent and variation in GPS-based mobility across three visits in the Trying to Understand Relationships, Networks and Neighborhoods among Transgender Women of Color (TURNNT) Cohort Study, a 1-year prospective cohort of transgender women of color aged 18–55 from New York, NY. Participants wore a standalone GPS device for one week at each visit. We visualized 7,415,171 GPS data points at baseline, 5,903,177 at 6-months, and 3,322,066 at 12-months. Participants covered a large spatial extent across all waves but specific locations visited varied, highlighting the importance of repeated GPS data collection over time. Longitudinal GPS data shows promise in characterizing mobility and exposure patterns over time in a marginalized population, offering methodological insights for future spatial epidemiologic research.