Early- and Late-Stage Cancer Diagnosis Under 3 Years of Medicaid Expansion.

introductionHealth insurance expansions may increase early detection of cancer and reduce late-stage cancer incidence. The study assesses the effects of the Affordable Care Act Medicaid expansions on rates of early- and late-stage cancer diagnosis up to 3 years after implementation.

methodsPopulation-based quasi-experimental analysis of nonelderly adults was conducted in 732 counties from the 2010-2016 Surveillance, Epidemiology, and End Results Program cancer registry data. Multivariate event study regressions were estimated to compare annual changes in county-level rates of cancer diagnoses in states that expanded Medicaid with those that did not. Data analysis was performed from May to October 2019.

resultsMedicaid expansion was associated with an increase in early-stage cancer diagnoses of 21.3 per 100,000 population (95% CI=2.9, 35.2) or 9.14% of population in its first year; estimates for Years 2 and 3 were also positive but smaller and not statistically significant. There was a marginally significant reduction in late-stage diagnoses of 8.7 per 100,000 population (95% CI= -25.0, 3.4) or 5.7% of population relative to baseline, 3 years after Medicaid expansion. There was no detectable effect of expansion on total diagnoses.

conclusionsMedicaid expansions increased early-stage cancer diagnosis in the first year of expansion, but effects dissipated in subsequent years, suggesting a response to pent-up patient demand for screening and diagnostic services immediately after expansion. There was also suggestive evidence of reductions in late-stage diagnosis in the third year of Medicaid expansion, highlighting the potential role of public health insurance in improving cancer outcomes among nonelderly adults.