How does on-demand delivery impact the accessibility and equity of community pharmacies? Perspective from groups with heterogeneous geographic-digital barriers.

Accessibility to community pharmacy service (CPS) is a key concern in public health and spatial planning. Although on-demand delivery may expand service opportunities through digital platforms and third-party riders, its contribution to CPS potential accessibility and equity remains underexplored. Using 647 community units in central Tianjin, China, and survey-derived parameters from 600 questionnaires (83.5% response rate), this study extends the Two-Step Floating Catchment Area (2SFCA) method by incorporating multidimensional supply capacity and a time-decay function weighted by modeled supplier-selection probability. Communities were classified into four groups according to geographic and digital barriers, and Geodetector was applied to examine factors associated with spatial heterogeneity in potential accessibility. Results reveal substantial group differences. In-store dispensing provides higher potential accessibility for groups with low geographic barriers, whereas on-demand delivery shows a relative accessibility advantage for groups facing high geographic or dual barriers. For these groups, delivery is also associated with a more equitable distribution of potential service opportunities, with Gini coefficients 0.08-0.12 lower than those for in-store dispensing. Factor interactions generally show greater explanatory power than individual factors, with prominent associations shifting from population size to interactions involving age structure and socioeconomic characteristics. These findings support differentiated pharmacy planning and closer coordination between offline mobility and online delivery networks.