Geospatial data

All residential, injury, and death addresses were geocoded within ArcGIS (ESRI, Redlands, CA). Unmatched addresses were then reviewed manually and geocoded using ArcGIS or the R package tidygeocoder [17]. In cases where decedents were listed as homeless or where no address was recorded, these cases were not geocoded. Decedents with residential addresses outside Connecticut were excluded. Injury addresses were used as primary locales for the space-time model and mapping the spatial trends. If injury addresses were unknown, residential addresses were used instead. If both addresses were unknown, death addresses were used. The geocoded overdose deaths were then assigned to one of the 169 corresponding cities or towns in Connecticut.