Medicaid Expansion and Stage at Diagnosis, Timely Initiation and Receipt of Guideline-Concordant Treatment, and Survival Among People With Non–Small Cell Lung Cancer

Abstract

PURPOSE To examine the associations between Medicaid expansion and stage at diagnosis, timely initiation and receipt of guideline-concordant treatment, and 5-year overall survival (OS) among people with non–small cell lung cancer (NSCLC). METHODS Individuals newly diagnosed with stage I to IV NSCLC at age 18-64 years between January 1, 2004, and December 31, 2023, in 50 states and Washington, DC, were identified from the National Cancer Database. We examined the association of Medicaid expansion and (1) early-stage diagnosis (I and II); (2) timely initiation of guideline-concordant treatment within 30 days after diagnosis; (3) receipt of all first-course guideline-concordant treatment; and (4) 5-year OS. We applied conventional and updated (Sun and Abraham) difference-in-differences (DID) approaches to examine the changes in study outcomes associated with Medicaid expansion using multivariable linear probability models to estimate stage and treatment and multivariable flexible parametric survival models to investigate survival overall and by key factors. RESULTS Compared with people in nonexpansion states (n = 164,228), people in expansion states (n = 350,290) were more likely to be female, non-Hispanic White, or living in areas with higher family income or in nonmetropolitan areas. Medicaid expansion was associated with increases in early-stage NSCLC diagnosis (DID: 1.02 percentage points [ppt; 95% CI, 0.52 to 1.52]), timely treatment initiation (2.10 ppt [95% CI, 0.05 to 4.15]), and higher 5-year OS (1.79 ppt [95% CI, 1.32 to 2.26]). In stratified analyses, people living in areas with lower household income were more likely to benefit from Medicaid expansion. CONCLUSION Medicaid expansion was associated with improvements in early detection, timeliness of guideline-concordant treatment, and survival for people with NSCLC. Anticipated Medicaid coverage losses may jeopardize these gains.