Vulnerability Index Approach to Identify Pharmacy Deserts and Keystone Pharmacies.

Importance: Community pharmacies are crucial for public health, providing essential services such as medication dispensing, vaccinations, and point-of-care testing. Addressing disparities in pharmacy access, particularly in underserved rural and low-income areas, is critical for health equity. Objective: To identify areas in the US at risk of becoming pharmacy deserts through the development of a novel pharmacy vulnerability index. Design, Setting, and Participants: This population-based cross-sectional study in the contiguous 48 states performed geographic information systems analysis of pharmacy data from the National Council for Prescription Drug Programs (NCPDP) dataQ. Participants included all open-door pharmacies (community or retail pharmacies open to the general public without restrictions on who can access its services) in the US as of February 2024. Statistical analysis was performed from July to August 2024. Exposure: The primary exposure was travel time to pharmacies across the US. Main Outcomes and Measures: A pharmacy desert was defined as a census tract where the travel time to the nearest pharmacy exceeds the supermarket access time for that region and urbanicity level. Building on this definition, a pharmacy vulnerability index was developed, which indicates the number of pharmacies that would need to close for a census tract to become a pharmacy desert. Tracts with a pharmacy vulnerability index of 1, depending solely on a single pharmacy for access, were identified as at risk of becoming deserts. Subpopulation totals and percentages living in pharmacy deserts or relying on keystone pharmacies were computed, and then stratified by urbanicity and race. Results: Among 321.3 million individuals (39.7 million [12.3%] Black, 59.0 million [18.2%] Hispanic, 195.0 million [60.3%] White) in the contiguous US, 57.1 million (17.7%) were identified as living in pharmacy deserts, with 28.9 million (8.9%) additionally relying on a single pharmacy for access. Small rural areas were particularly affected, with a higher dependency on single pharmacies (4.1 million individuals [14.3%]). Conclusions and Relevance: In this cross-sectional study of pharmacy access in the US, significant disparities in pharmacy access were identified, especially pronounced in small rural areas. Targeted policy interventions, such as incremental reimbursement rates or other monetary incentives, are needed to ensure the financial sustainability of pharmacies that serve as the sole source of pharmacy services in at-risk areas.