Changes in the Proportion of Patients Presenting with Early Stage Colon Cancer over Time Among Medicaid Expansion and Non-expansion States: A Cross-Sectional Study.

BACKGROUND The 2010 Affordable Care Act mandated preventative screening coverage and provided participating states support for Medicaid coverage. The association of Medicaid expansion with colon cancer stage at diagnosis is unknown. OBJECTIVE To determine whether the proportion of patients diagnosed with early stage colon cancer changed over time within states that expanded Medicaid compared to non-expansion states. DESIGN Cross-sectional cohort study. SETTING Multicenter registry data from the National Cancer Database (2006-2016). PATIENTS There were 25,462 uninsured or Medicaid-insured patients with newly diagnosed colon cancer. EXPOSURE Residence in 2014 Medicaid expansion or non-expansion states. MAIN OUTCOME MEASURES Annual proportion of patients with early (I-II) versus late (III-IV) stage colon cancer. RESULTS A total of 10,289 patients were identified in expansion states and 15,173 patients in non-expansion states. Cohorts were similar in age (median 55 years) and sex (46.7% female). A greater proportion of patients in non-expansion states were Black (33.4% vs 24.0%) and resided in a zip code with median income < $38,000 (39.7% vs 28.2%) and lower educational status (37.4% vs 28.1%). In 2006, proportions of patients with early stage colon cancer in expansion and non-expansion cohorts were similar (33.2% vs 32.5%). The proportion of patients with early stage within non-expansion states declined by 0.8% per year after 2014, whereas the proportion within expansion states increased by 0.9% per year after 2014 (p<0.05). By 2016, the absolute difference in the propensity-adjusted proportion of early stage colon cancer was 8.8% (39.7% vs 30.9%, p<0.001). LIMITATIONS National Cancer Database data is obtained only from Commission on Cancer-accredited sites and is not population-based. CONCLUSIONS Following Medicaid expansion in 2014, the proportion of patients diagnosed and treated at Commission on Cancer-accredited facilities with early stage colon cancer increased within expansion states and decreased in non-expansion states. Increase in insurance coverage may have facilitated earlier diagnosis among patients in expansion states. See Video Abstract at http://links.lww.com/DCR/B804 .