THE EFFECT OF STATE INSURANCE MANDATES ON INFANT IMMUNIZATION RATES

Sibling spillovers and the choice to get vaccinated: Evidence from a regression discontinuity design

We investigate the effects of introducing population-wide free-of-charge Human Papillomavirus (HPV) vaccination programs on the targeted adolescent cohorts and their siblings. For identification, we rely on regression discontinuity designs and high-quality Danish administrative data to exploit that date of birth determines program eligibility. We find that the programs increased the HPV vaccine take-up of both the targeted children (53.2 percentage points for girls and 36.0 percentage points for boys) and their older same-sex siblings (4.5 percentage points for sisters and 3.5 percentage points for brothers). We show that while the direct effects of the programs reduced HPV vaccine take-up inequality, the spillover effects, in contrast, contributed to an increase in vaccine take-up inequality highlighting the potential importance of spillover effects in the determination of distributional consequences of public health programs. Finally, we find some evidence of cross-vaccine spillovers.

Direct and crowding-out effects of a Hepatitis B vaccination campaign

We evaluate the direct and spillover causal effects of a Hepatitis B (HB) vaccination campaign in French schools on the vaccination adherence of the targeted pupils. Using a regression discontinuity design, we show that this campaign created an exogenous shock on vaccination behavior, increasing the HB vaccination rate for children aged 11 and above. At the same time, we show a drop in the measles, mumps, and rubella (MMR) vaccination rate of the targeted pupils and an increase in the parental belief that measles is a benign disease. We interpret these results as a salience effect: the focus on HB vaccination leads to a decrease in the belief that other vaccines are as important. The effect on MMR vaccination was relatively unexpected and may imply a negative externality. Measles is an extremely contagious disease. If the vaccination rate falls, the disease will spread further, raising the question of the net effect of the HB vaccination campaign on the well-being of the population.

Consequences of a shortage and rationing: Evidence from a pediatric vaccine

Shortages and rationing are common in health care, yet we know little about the consequences. We examine an 18-month shortage of the pediatric Haemophilus Influenzae Type B (Hib) vaccine. Using insurance claims data and variation in shortage exposure across birth cohorts, we find that the shortage reduced uptake of high-value primary doses by 4 percentage points and low-value booster doses by 26 percentage points. This suggests providers largely complied with rationing recommendations. In the long-run, catch-up vaccination occurred but was incomplete: shortage-exposed cohorts were 4 percentage points less likely to have received the ir booster dose years later. We also find that the shortage and rationing caused provider switches, extra provider visits, and negative spillovers to other care.

Personal belief exemptions for school-entry vaccinations, vaccination rates, and academic achievement

Nonmedical exemptions from school-entry vaccine mandates are receiving increased policy and public health scrutiny. This paper examines how expanding the availability of exemptions influences vaccination rates in early childhood and academic achievement in middle school. We leverage 2003 legislation that granted personal belief exemptions (PBE) in Texas and Arkansas, two states that previously allowed exemptions only for medical or religious regions. We find that PBE decreased vaccination coverage among Black and low-income preschoolers by 16.1% and 8.3%, respectively. Furthermore, we find that those cohorts affected by the policy change in early childhood performed less well on standardized tests of academic achievement in middle school. Estimated effects on test scores were largest for Black students and economically disadvantaged students.

Pneumococcal Vaccination Mandates for Child Care: Impact of State Laws on Vaccination Coverage at 19-35 Months

INTRODUCTION

Vaccination mandates for elementary and middle school attendance have been shown to increase vaccination rates and decrease the burden of vaccine-preventable diseases. Fewer studies have evaluated similar requirements for child care attendance. This study provides robust, quasi-experimental estimates of the effect of state laws mandating the pneumococcal conjugate vaccine for child care attendance on vaccination coverage among children aged 19-35 months.

METHODS

Using provider-verified immunization histories from the 2001-2018 waves of the National Immunization Survey-Child and leveraging the staggered implementation of vaccination requirements across states, a generalized difference-in-differences approach was implemented to compare regression-adjusted changes in vaccination coverage among children in states with and without a child care mandate for the pneumococcal conjugate vaccine. The dynamics of estimated treatment effects were analyzed using an event study analysis. All data analyses were conducted in 2019‒2020.

RESULTS

State adoption of a child care mandate for the pneumococcal conjugate vaccine increased the likelihood that resident children aged 19-35 months completed the 4-dose pneumococcal conjugate vaccine series by 3.12 percentage points (p<0.01). Statistically significant gains in pneumococcal conjugate vaccine coverage were identified in the first year following policy implementation and were found to persist over a period of ≥7 years.

CONCLUSIONS

Results indicate that state adoption of a child care mandate for the pneumococcal conjugate vaccine leads to an increase in the proportion of resident children aged 19-35 months who are up to date with pneumococcal conjugate vaccine.

Impacts of anticancer drug parity laws on mortality rates

This study investigates the impacts of anticancer drug parity laws on mortality rates in the United States using a difference-in-differences approach. Using data from 2004 to 2017 Compressed Mortality Files, we show that the anticancer drug parity laws reduce the mortality rate for head/neck malignant cancers but have no impact on malignant cancers of other types. We also rule out an insurance expansion channel that may influence the relationship between anticancer drug parity laws and malignant cancer mortality. Our results are robust to various specifications and falsification tests. Our findings imply that providing equal access to oral anticancer drugs is an effective tool for the prevention of premature mortality.

Vaccination take-up and health: Evidence from a flu vaccination program for the elderly

We analyze the effects of a vaccination program providing free flu vaccine to individuals aged 65 or more on take-up behavior and hospitalization. Using both administrative and survey data, we implement a regression discontinuity design around the threshold at age 65, and find that the effect of the program on take-up ranges between 70% and 90% of the average vaccination rate for individuals aged less than 65. We show that this effect is not entirely driven by an income channel, but also depends on the expected benefits of vaccination. The results on health outcomes provide suggestive evidence that the program reduces the likelihood of emergency hospitalization.

Disease outbreaks, healthcare utilization, and on-time immunization in the first year of life

This paper examines the determinants of parental decisions about infant immunization. Using the exact timing of vaccination relative to birth, we estimate the effects of local pertussis outbreaks occurring in utero and during the first two months of life on the likelihood of on-time initial immunization for pertussis and other diseases. We find that parents respond to changes in perceived disease risk: pertussis outbreaks within a state increase the rate of on-time receipt of the pertussis vaccine at two months of age, particularly among low-socioeconomic status (SES) subgroups. In addition, we find that pertussis outbreaks increase the likelihood of immunization against other vaccine-preventable diseases. Spillover effects in low-SES subgroups are as large as direct effects and are present only for vaccines given during the same visit as the pertussis vaccine, which suggests that provider contact may be a key factor in infant vaccination decisions in poor families.

Information, education, and health behaviors: Evidence from the MMR vaccine autism controversy

In the wake of strong, although later refuted, claims of a link between autism and the measles-mumps-rubella (MMR) vaccine, I examine whether fewer parents immunized or delayed vaccinations for their children and if there was a differential response by mother's education level. Using various controls and a differencing strategy that compares in MMR take-up with other vaccines, I find that the MMR-autism controversy led to a decline in the immediate years and that there were negative spillovers onto other vaccines. I also find evidence that more highly educated mothers responded more strongly to the controversy either by not immunizing their children altogether or, to a lesser degree, delaying vaccination. Moreover, the educational gap was greater in states where there was greater media attention devoted to the controversy. This is consistent with the health allocative efficiency hypothesis whereby part of the education gradient in health outcomes is due to more-educated individuals absorbing and responding to health information more quickly. However, unlike in the United Kingdom, where previous studies find that the gap was eliminated after the link was refuted, the evidence for the United States suggests that the educational gap persisted.

Effectiveness of vaccination recommendations versus mandates: Evidence from the hepatitis A vaccine

I provide novel evidence on the effectiveness of two vaccination policies - simple non-binding recommendations to vaccinate versus mandates requiring vaccination prior to childcare or kindergarten attendance - in the context of the only disease whose institutional features permit a credible examination of both: hepatitis A. Using provider-verified immunization data I find that recommendations significantly increased hepatitis A vaccination rates among young children by at least 20 percentage points, while mandates increase rates by another 8 percentage points. These policies also significantly reduced population hepatitis A incidence. My results suggest a range of policy options for addressing suboptimally low population vaccination rates.