Date of Award

January 2026

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)

Department

School of Public Health

First Advisor

Linda Niccolai

Abstract

Human papillomavirus (HPV) vaccination and screening are the two primary strategies for preventing HPV-associated cervical cancer, yet progress toward national coverage goals remains uneven. The Affordable Care Act’s Medicaid expansion, adopted by states on a staggered timeline since 2014, is a major policy lever for reducing barriers to preventive care, but its association with HPV-related prevention has not been examined across both services in a unified framework.

This thesis uses a state-level ecological design to examine the association between Medicaid expansion status and two outcomes: (1) HPV vaccination coverage among adolescents aged 13 to 17 (NIS-Teen, 2012–2024), measured as series completion (Up-to-Date) and initiation (≥1 dose); (2) cervical cancer screening among women aged 21 to 65 (BRFSS, 2012–2020), measured as Pap test within the past 3 years. States (N = 51) were classified by expansion timing: Early Adopters (2014, n = 26), Mid Adopters (2015–2016, n = 5), Late Adopters (2017 or later, n = 9), and Never Adopters (n = 11). Descriptive trends, t-tests, ANOVA, and baseline-controlled regression were applied in parallel to both outcomes.

The results revealed a clear divergence. At the 2024 endpoint, Early Adopter states had 7 to 10 percentage points higher HPV vaccination coverage than Never Adopter states across all four sex-measure combinations (Up-to-Date: 69.2% vs. 58.6% among females, 65.2% vs. 57.2% among males; ≥1 Dose: 82.3% vs. 74.9% among females, 80.5% vs. 73.4% among males; all p < 0.05, Cohen’s d > 0.8). No other pairwise contrast was significant. For cervical screening, no association with expansion status was observed: all four categories declined by 15 to 18 percentage points between 2012 and 2020 and reached statistically indistinguishable 2020 endpoints (Early Adopters 67.8%, Never Adopters 68.8%; p = 0.400).

This divergence suggests that Medicaid expansion’s relationship to preventive services is pathway-specific. Cervical screening is supported by overlapping safety-net programs operating independently of expansion status, including the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) and Title X clinics, which provide free or subsidized screening to low-income and uninsured women in all states and may attenuate any differential expansion effect. HPV vaccination lacks a comparable safety-net architecture beyond the Vaccines for Children program, leaving it more responsive to insurance-related pathways such as visit-level cost-sharing, primary-care continuity, and parental engagement with the healthcare system. These findings carry implications for the remaining non-expansion states and for complementary strategies needed to advance cervical cancer elimination.

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This is an Open Access Thesis.

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