Pneumococcal vaccination coverage among US adults enrolled in Medicaid and newly diagnosed with underlying medical conditions

ABSTRACT

Background

Adults with chronic or immunocompromising conditions have an elevated risk of invasive pneumococcal disease, yet their pneumococcal vaccination rates remain low.

Methods

This retrospective cohort study used the IBM MarketScan® Multi-State Medicaid database to examine pneumococcal vaccination uptake among adults 19–64 years of age with underlying conditions. Gompertz accelerated failure time model was used to examine factors associated with vaccination.

Results

In the study population of 108,159 adults, the vaccination rate was 4.1% after 1 year of follow-up and 19.4% after 10 years. The mean time from initial diagnosis to vaccination was 3.9 years. Adults aged 35–49 and 50–64 years (relative to 19–34) or those receiving an influenza vaccination were more likely to receive a pneumococcal vaccination. Adults with HIV/AIDS were more likely, while adults with chronic heart or lung disease, alcohol or tobacco dependence, or cancer were less likely to be vaccinated than adults with diabetes mellitus. Adults diagnosed by specialists were less likely to be vaccinated than those diagnosed by primary care providers.

Conclusions

The rates of pneumococcal vaccination among adults with Medicaid plans and underlying conditions were well under Healthy People Initiative targets. Insights into factors associated with vaccination can inform efforts to improve vaccination rates among this population.

KEYWORDS:

• pneumococcal vaccination coverage
• adults
• Medicaid
• chronic conditions
• immunocompromising conditions

Acknowledgments

The authors thank ScribCo for editorial support; Anna Ostropolets for analytic support; Alexandra Anne Bhatti, Temi Folaranmi, Grace Gregorio, & Eric M. Sarpong for their review of the manuscript.

Declaration of interest

Junqing Liu, Kelly D. Johnson, and Linda Shoener Dunham are employees of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, U.S.A and hold shares in Merck & Co., Inc., Rahway, NJ, U.S.A.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

Conception and design: Junqing Liu, Kelly D. Johnson, Linda Shoener Dunham. Analysis and interpretation of the data: Junqing Liu, Kelly D. Johnson, Linda Shoener Dunham. Drafting of the paper: Junqing Liu, Kelly D. Johnson, Linda Shoener Dunham. Revising the paper critically for intellectual content: Junqing Liu, Kelly D. Johnson, Linda Shoener Dunham. Final approval of the version to be published: Junqing Liu, Kelly D. Johnson, Linda Shoener Dunham. All authors agree to be accountable for all aspects of the work.

Additional information

Funding

This paper was funded by Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.