Evaluation of Insurance Coverage and Cancer Stage at Diagnosis Among Low-Income Adults With Renal Cell Carcinoma After Passage of the Patient Protection and Affordable Care Act

IMPORTANCE: The association of the Patient Protection and Affordable Care Act (ACA) with insurance status and cancer stage at diagnosis among patients with renal cell carcinoma (RCC) is unknown. OBJECTIVE: To test the hypothesis that the ACA may be associated with increased access to care through expansion of insurance, which may vary based on income. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort analysis included patients diagnosed with RCC from January 1, 2010, to December 31, 2016, in the National Cancer Database. Data were analyzed from July 1 to December 31, 2020. The periods from 2010 to 2013 and from 2014 to 2016 were defined as pre- and post-ACA implementation, respectively. Patients were categorized as living in a Medicaid expansion state or not. EXPOSURES: Implementation of the ACA. MAIN OUTCOMES AND MEASURES: The absolute percentage change (APC) of insurance coverage was calculated before and after ACA implementation in expansion and nonexpansion states. Secondary outcomes included change in stage at diagnosis, difference in the rate of insurance change, and change in localized disease between expansion and nonexpansion states. Adjusted difference-in-difference modeling was performed. RESULTS: The cohort included 78 099 patients (64.7% male and 35.3% female; mean [SD] age, 54.66 [6.46] years), of whom 21.2% had low, 46.2% had middle, and 32.6% had high incomes. After ACA implementation, expansion states had a lower proportion of uninsured patients (adjusted difference-in-difference, −1.14% [95% CI, −1.98% to −1.41%]; P = .005). This occurred to the greatest degree among low-income patients through the acquisition of Medicaid (APC, 11.0% [95% CI, 8.6%-13.3%]; P < .001). Implementation of the ACA was also associated with an increase in detection of stage I and II disease (APC, 4.0% [95% CI, 1.6%-6.3%]; P = .001) among low-income patients in expansion states. CONCLUSIONS AND RELEVANCE: Among patients with RCC, ACA implementation was associated with an increase in insurance coverage status in both expansion and nonexpansion states for all income groups, but to a greater degree in expansion states. The proportion of patients with localized disease increased among low-income patients in both states. These data suggest that ACA implementation is associated with earlier RCC detection among lower-income patients.