Shot in the Arm: State Policies for Pharmacy-administered Vaccines and the Likelihood of Adult Immunization
*Names in bold indicate Presenter
A leading pharmacy chain in the United States provided us data on the availability of the live attenuated influenza vaccine for each of its 8,000+ unique stores for years 2006-2011. Considering the extent of this chain’s market coverage we assume that they were either responding to or creating a competitive force to provide the service, and we use their data to proxy for local access to pharmacy-administered vaccinations. We constructed a county-level treatment in which we consider residents of a county as treated if more than 5% of the chain’s stores in that county carried the vaccine during a given year. We merged these treatment indicators with nationally representative cross-sectional survey data from the Behavioral Risk Factor Surveillance System (BRFSS) to generate our analytic sample. The survey data included key demographic characteristics, health behaviors, and vaccines received in the past 12 months (n=1,659,036 for influenza and n=1,548,077 for pneumococcal vaccines). Our empirical strategy involved conducting an interrupted time series analysis to identify the impact of access to pharmacist-administered vaccines over time on the likelihood of reporting having been immunized. We also conducted sub-group analyses of high-risk populations including people over the age of 65, smokers, people with diabetes, people with heart disease, and heavy drinkers. Finally, as a robustness check, we tested the sensitivity of our treatment definition by using 10, 25, 50, 75% stores per county thresholds.
The results of our analysis indicate that allowing pharmacies to administer vaccines increased the likelihood of influenza and pneumococcal immunizations. This observed increase in vaccinations may be due to reduced barriers to care from pharmacies, such as extended hours of operation, convenience of location, and higher frequency of visits. Our findings provide evidence that expanding access to vaccine delivery services can increase the likelihood of immunization - a positive result with important significance for public health.