Pharmacy deserts and patients with breast cancer receipt of influenza vaccines.

BACKGROUND

Yearly influenza vaccination is strongly recommended at age 65 and reimbursed by Medicare without copays or deductibles at pharmacies and clinical settings. Uptake is low among patients with a high risk for influenza complications and good access to specialist care, such as recent cancer survivors. We hypothesized that more accessible pharmacies could be associated with higher immunization uptake in such patients.

OBJECTIVES

To determine whether pharmacy access is associated with influenza vaccination in subjects recently diagnosed with breast cancer, and whether this association differs by additional risk factors for influenza complications.

METHODS

We examined a cohort of patients with stage 0-III breast cancer diagnosed 2011-2015 from the Surveillance, Epidemiology, and End Results-Medicare cancer registry. All retail pharmacies in the United States were identified, and pharmacy access was measured by assessing supply and demand in each census tract using a 2-stage floating catchment area approach that accounted for pharmacy driving distances recommended by the Centers for Medicare and Medicaid Services. We examined the association of pharmacy access with influenza vaccination after breast cancer diagnosis in regression models.

RESULTS

More than 11% of 45,722 patients with breast cancer lived in census tracts where no pharmacies were within recommended driving distances from the population-weighted tract center. Vaccination in the year after diagnosis was less likely for patients in these very low-access tracts (adjusted odds ratio 0.92 [95% CI 0.86-0.96]), black (0.55 [0.51-0.60]) and Hispanic (0.76 [0.70-0.83]) women, and Medicaid recipients (0.74 [0.69-0.79]). Vaccination was inversely associated with per capita income in the subject's census tract, but there was no difference in the pharmacy effect by race, ethnicity, or census tract income.

CONCLUSION

Very low pharmacy access is associated with modest reductions in vaccination that could be useful for policy and planning regarding vaccinator resources and outreach.