Effect of Changes to California Medicaid Dental Benefits on Earlier Diagnosis of Oral Cavity Cancer

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In a study reported in a research letter in JAMA Oncology, Kana et al found that changes to Medicaid dental benefits in California from comprehensive to emergency services—and then back to comprehensive—were associated with reduced, then increased, percentages of cases of oral cavity cancer diagnosed at early stages (0 to II).

Study Details

The study used the Surveillance, Epidemiology, and End Results database to identify patients diagnosed with oral cavity cancer in California between January 2007 and December 2016. A multivariate difference-in-difference (DID) analysis was used to compare changes in percentages of local (stage 0 to II) oral cavity cancer diagnoses for patients with Medicaid vs those with Medicare or private coverage after Medicaid coverage changed from comprehensive (during the period of January 2007 to July 2009) to emergency (during the period of January 2010 to December 2013), and then back to comprehensive during the period of July 2014 to December 2016. DID analysis was adjusted for age, sex, race/ethnicity, county median household income, county percentage of residents with bachelor’s degree, and county urbanization.

Key Findings

Among 1,325 patients with oral cavity cancer and Medicaid coverage, the percentages of patients diagnosed at stage 0 to II decreased from 46.5% to 39.6% when benefits were changed from comprehensive to emergency (absolute difference = −6.9%) and increased from 39.6% to 46.6% when benefits were expanded back to comprehensive (absolute difference = 6.9%).

Among 7,428 patients with oral cavity cancer and Medicare or private coverage, the percentages of patients diagnosed at stage 0 to II were 61.5%, 62.1%, and 63.6% during the three time periods.

DID analysis showed that compared to patients with Medicare or private insurance, the change from comprehensive to emergency coverage was associated with a significant decrease in Medicaid patients presenting with stage 0 to II oral cavity cancer (DID =  −7.4%, 95% confidence interval [CI] =  −14.6% to −0.2%), and that the change back to comprehensive coverage was associated with a borderline significant increase (DID = 5.3%, 95% CI = −0.1% to 12.0%).

The investigators stated, “Results from this cohort study reveal that comprehensive dental insurance was associated with localized presentation of oral cavity cancer among California Medicaid beneficiaries between 2007 and 2016. Early diagnosis is important because the 5-year survival rate for localized oral cavity cancer is approximately 70% to 90% vs less than 50% for locoregionally advanced (stage III to IV) disease… our findings suggest that comprehensive dental coverage by national and state government–sponsored insurance is associated with the potential for early cancer detection.”

John D. Cramer, MD, of the Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, is the corresponding author for the JAMA Oncology article.

Disclosure: For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.