Association for Public Policy Analysis & Management

As of January, 2017, 15 states have implemented laws aimed at increasing influenza vaccination rates among hospital workers. Broadly, these laws mandate that hospitals offer the influenza vaccine to all workers; some states further mandate the vaccine be provided free of charge, or require all workers to receive the vaccine, unless they have a valid exemption. We examine the extent to which these laws were associated with a reduction in pneumonia and influenza (PI) mortality.

To estimate the effects of hospital worker influenza vaccination laws, we used difference-in-differences models and identified the effects of the laws by comparing rates of PI mortality in states that implemented a law versus states that did not, before versus after implementation. Mortality data are from the restricted-access multiple cause of death files from the National Vital Statistics System that includes state identifiers, for the years 1995-2016.

Implementation of a state law requiring hospitals to offer the influenza vaccine to their employees is associated with a significant reduction in the PI mortality rate (difference-in-differences coefficient, -0.146 deaths per 100,000 population; P=0.016), with the largest effects occurring among the elderly. These mortality reductions are observed only during flu season months; we find no statistically significant change in PI mortality during non-flu season months. Further analyses also show that adoption of a hospital worker influenza vaccination law is not associated with significant changes in mortality due to any non-PI cause of death.

Adoption of state laws requiring hospitals to offer the influenza vaccine is associated with a significant reduction in PI mortality, particularly among the elderly. This suggests that vaccinating health care workers may substantially reduce the spread of influenza and may be an effective way to protect some of the most vulnerable populations.