Pharmacy access and shingles vaccinations in the US: a propensity score matching analysis

Community pharmacists provide many important healthcare services, including routine adult vaccinations. However, an estimated 15.8 million people in the US live in pharmacy deserts and may lack access to these services. The relationship between pharmacy deserts and adult vaccine receipt has yet to be thoroughly explored empirically.

We evaluated the relationship between census tract-level pharmacy access and shingles vaccination receipt.

This propensity score matched analysis used 2022 vaccination data from seven collaborating State Departments of Health: Colorado, Louisiana, Massachusetts, Nevada, Oklahoma, Washington, and Wisconsin. Census tracts in those states were classified based on their access to community pharmacies in April 2022. The dataset for analysis contained 9652 census tracts representing 13.7 million adults aged 50+ years.

Our primary exposure was whether a census tract was a "pharmacy desert", defined as being both low-income and having low geographic access to pharmacies. Our secondary exposure was whether a tract had low geographic access to pharmacies regardless of income status of that tract.

The primary outcome was completed shingles vaccinations per 1000 population age 50+ years in 2022.

Pharmacy deserts had 0.4 fewer shingles vaccinations per 1000 population (p = 0.83; 95% CI -3.8, 3.6) compared to matched non-pharmacy-desert tracts. Our secondary analysis indicated that low-access tracts had 2.4 fewer vaccinations per 1000 population (p = 0.004, 95% CI: -3.9, -0.7).

Low pharmacy access is associated with lower rates of shingles vaccination. The definition of pharmacy desert that includes a low-income criterion may not add further precision in identifying areas with inadequate access to pharmacy-based vaccinations. Efforts at the state and national levels to prevent pharmacy closures and support pharmacists in delivering care may improve access to important pharmacy services such as vaccination.