Examining the effect of Medicaid expansion on early detection of head and neck cancer of the oral cavity and pharynx by HPV‐type and generosity of dental benefits

Abstract

BackgroundOver a decade of evidence supports the claim that increased access to insurance through Medicaid expansions improves early detection of cancer. Yet, evidence linking Medicaid expansions to early detection of head and neck cancers (HNC) of the oral cavity and pharynx, specifically, may be limited by the lack of attention to Human Papillomavirus (HPV) etiology, generosity of dental coverage, and valid inference analyzing state cancer registry data.AimsThis study reexamined the effect of Medicaid expansion on early detection of HPV+/− HNC in states offering extensive dental benefits.Materials and MethodsSpecialized data from the Surveillance, Epidemiology, and End Results (SEER) program was analyzed to account for, previously unmeasurable, differential detection patterns of HNCs associated with HPV. Then, to identify the effect of increasing Medicaid eligibility on staging patterns in states offering extensive benefits amidst potentially non‐common trends between states, a “Triple Differences” design identifies the differential effect of Medicaid Expansion (with dental coverage) on HPV‐negative HNCs relative to the change in HPV‐positive HNCs. For valid inference analyzing a small number of state clusters (12) in cancer registry data, each regression model applies a Wild Cluster Bootstrap.ResultsExpanding Medicaid eligibility was found to be associated with a decrease in the proportion of distant‐stage diagnoses of HPV(−) HNCs, but only among states which increased Medicaid dental generosity at the time of Medicaid expansion.ConclusionsThese results suggest that adding extensive Medicaid dental benefits was the primary mechanism impacting HNC detection. This study highlights the potential positive spillover effects of policies which increase access to public dental coverage for low‐income adults, while also showing the limitation of access to dental services for improving early detection of HPV+ HNCs.

Eliminating Medicaid dental benefits and early‐stage oral cancer diagnoses

“…This result is not surprising, given visual examinations of the mouth during a comprehensive dental exam are less likely to detect abnormalities deep in the head and neck area. 49,52 Unfortunately, despite the proliferation of a preventive vaccine, OPC incidence is rising. 53,54 Clearly, improving outcomes for advancedstage OPC cannot yet rely on increasing access to dental screening protocols.…”

“…While Medicaid expansion was touted as a critical policy for expanding access to dental services, this benefit was primarily realized in states which both expanded Medicaid under the Affordable Care Act and offered extensive Medicaid dental benefits. 39,49 During the late 2010s, states also began shifting more of their Medicaid dental service delivery toward privatized, managed care systems. 50,51 How these changes have impacted access to care for oral cancer remain unclear.…”

Late‐Stage Oral Cancer Detection After California and Illinois Restored Medicaid Dental Benefits

“…These findings reaffirm the evidence that access to dental care is critical for systems of oral cancer prevention and control. 1,2,[21][22][23][24] The current study, however, contributes new evidence by analyzing (1) more recent data, (2) an additional treatment state, and (3) a large enough sample to conduct valid subgroup analyses by sociodemographic factors.…”

“…Policies ensuring that low‐income adults have adequate access to preventive dental services are essential for early detection of oral cancer. 1 , 2 Yet, many low‐income adults face significant financial barriers to visiting a dentist: the healthcare professional is most likely to screen for oral cancer. 3 , 4 , 5 , 6 The primary government health insurance for low‐income adults, Medicaid, does not always cover dental benefits.…”

“…Previous research has shown a clear link between increasing Medicaid dental coverage and higher rates of early‐stage oral cancer diagnoses. 1 , 2 For instance, when California (CA) eliminated its Medicaid dental benefits in 2009, early‐stage diagnoses declined. 1 Then, when CA restored its Medicaid dental benefits in CA in 2014, the trend reversed, at least for nonoropharyngeal oral cancers and oral cancers not associated with human papillomavirus.…”