Study Finds Upsurge of Shingles Vaccination in Medicare Part D Following Elimination of Cost Sharing

New study findings evaluated the connection between eliminated cost sharing for vaccines covered by Part D through the Inflation Reduction Act (IRA) and the shingles vaccine (Shingrix; GSK), which accounts for more than 90% of Part D vaccinations.¹

The IRA was signed into law on August 16, 2022, and directs federal spending towards funding the internal revenue service’s resulting in lowering health care needs.² As a result of the IRA, effective January 1, 2023, the IRA removed cost sharing and deductibles for adult vaccines that were recommended by the Advisory Committee on Immunization Practices (ACIP) and covered under Medicare Part D.³

This was put into place to improve affordability of vaccines for Medicare beneficiaries because 2021 data showed that Medicare beneficiaries receiving vaccines covered under Medicare Part D paid $234 million out of pocket (OOP). The study authors noted that of the $234 million, the mean OOP cost was $76.94 for shingles.¹ However, in 2023, data showed that 10.3 million Medicare Part D enrollees received an ACIP-recommended vaccine free of charge, which saved more than $400 million OPP costs—with the majority vaccinated for RSV and shingles.³

A recent study aimed to assess the link between zero cost-sharing with uptake of shingles vaccination. Investigators used data from the IQIVA’s National Prescription Audit that included monthly shingles vaccinations administrated at retail pharmacies from January 2022 to December 2023. The study authors noted that they conducted a quasi-experimental difference-in-differences design that compared the changes in shingles vaccines administrated with Part D insurance to changes with commercial insurance. This was established to regulate the connection between the January 2023 implementation of the IRA policy eliminating OOP cost and the amount of total shingles vaccines dispensed, compared to dispensed with a $0 copay under Part D.¹

The study authors noted that they compared the outcomes before the policy was integrated (January through December of 2022) and after the policy was implemented (January through December of 2023). The researchers reported to use linear regression models with heteroskedasticity-robust standard errors and adjustment for trends in vaccines that were dispensed by year and calendar month.¹

“The plausibility of the parallel trends assumption was examined by testing whether trends in shingles vaccine dispensing from January 2022 through December 2022 differed between individuals with Part D vs commercial insurance,” said the study authors, in a news release.¹

Data from IQIVA’s National Prescription Audit found that a total of 16.3 million shingles vaccines were dispensed at retail pharmacies between January 2022 and December 2023, with 8.3 million individuals with Part d and 8 million with commercial insurance. The study authors noted that prior to IRA’s implementation from January 2022 through December 2022, significant differences in dispensed shingles vaccines were not displayed between both groups.¹

The results found that after IRA’s policy was put in place, the total amount of Part D shingles vaccinations administered increased by 46% as vaccinations dispensed with commercial insurance decreased by 21%, according to study authors.¹

“In regression analyses, the adjusted difference-in-differences estimate was 208 225 (95% CI, 187 829-228 622) total shingles vaccines dispensed per month (P < .001) and 400 720 (95% CI, 375 160-426 279) dispensed with zero cost sharing per month (P < .001),” said the study authors, in a news release.¹

Additionally, in December of 2023, shingles vaccinations paid for with Part D insurance with no patient cost sharing increased to approximately 100%, compared with 31% in December 2022. The study authors noted that the findings suggest that the IRA policy of eliminating OOP costs for Part-D covered vaccinations resulted in significant increases in shingles vaccines dispensed to individuals under Part D, compared to those commercially insured.¹

REFERENCES

1. Shingles Vaccination in Medicare Part D After Inflation Reduction Act Elimination of Cost Sharing. JAMA Network. News release. May 23, 2024. Accessed October 3, 2024. https://jamanetwork.com/journals/jama/article-abstract/2819156?resultClick=1.

2. Gallagher A. Pharmacist Education Is Necessary for Patient Understanding of Inflation Reduction Act. Pharmacy Times. News release. May 2, 2023. Accessed October 3, 2024. https://www.pharmacytimes.com/view/pharmacist-education-is-necessary-for-patient-understanding-of-inflation-reduction-act.

3. Inflation Reduction Act Research Series: Medicare Part D Enrollee Vaccine Use After Elimination of Cost Sharing for Recommended Vaccines in 2023. ASPE. News release, May 3, 2024. Accessed October 3, 2024. https://aspe.hhs.gov/reports/ira-elimination-vaccine-cost-sharing-2023#:~:text=Effective%20January%201%2C%202023%2C%20the,covered%20under%20Medicare%20Part%20D.