S305 Changes in Colorectal Cancer Incidence Associated With Medicaid Expansion: An Analysis of the National Cancer Database

Abstract

Introduction: The Affordable Care Act (ACA), enacted in 2010, increased insurance coverage for states that expanded Medicaid, but its impact across the United States on Colorectal Cancer (CRC) detection remains unclear. The National Cancer Database (NCDB) is a hospital-based cancer registry that captures approximately 75% of diagnosed cancers in the U.S. and Puerto Rico. This study used the NCDB to investigate the changes in the frequency of colon cancer incidence before and after Medicaid expansion. Methods: We compared all adult cases of CRC in the NCDB using ICD-codes from pre-Medicaid expansion in 2006-2009 to the period after full state participation in 2015-2018. Information on patient demographics (age, sex, race, insurance status, educational attainment, residential location, Charlson-Deyo Comorbidity Score (CDCS), staging at diagnosis) were queried. United States census data from 2010 and 2020 were used to standardize CRC incidence. Chi-square and t-test analysis were performed using SPSS v.28. Results: With the ACA, the proportion of those without insurance dropped from only 3.3% to 3.0% in the NCDB database. The total incidence of CRC was 569,659 patients for the two study periods. There were 86.4 cases per 100,000 diagnosed pre-Medicaid expansion and 92.5 cases per 100,000 post-Medicaid expansion. Patients diagnosed after expansion were younger 65.6±12.4 y vs 67.1±12.7 y. In the post-Medicaid expansion period, there was an increase in the incidence of CRC in males (52.7% vs 50.5%), Non-Hispanic Black (12.4% vs 11.5%) and Hispanic patients (6.9% vs 4.8%), patients with lower educational attainment (22.6% vs 21.6%), and patients with greater comorbidities via CDCS (5.0% vs 2.9%). Though there were statistically significant differences in income and residential location, these findings were not clinically significant. There was a slight shift in the incidence of CRC diagnosed at a later stage post-expansion. Results are summarized in Table. Conclusion: Medicaid expansion was associated with an increase in the incidence of CRC diagnosis despite a very modest drop in the proportion uninsured. The age of diagnosis decreased post-Medicaid expansion. There was also an increase in the proportion of males, minorities, patients with lower educational attainment, and those with a greater number of comorbid conditions. CRC was not found at an earlier stage of diagnosis despite an increase in the access to medical care. These findings highlight the impact of expanding health insurance coverage for all. Table 1. - Comparison of Patient Characteristics between Pre-Medicaid Expansion (2006-2009) and Post-Medicaid Expansion (2015-2018) Factors Pre-Expansion (2006-2009) n=266,109 Post-Expansion (2015-2018) n=303,550 p-value Age (SD) y - 67.13 (12.7) 65.55 (12.4) p< 0.001 Sex Male 134,445 (50.5) 159,973 (52.7) p< 0.001 Female 131,664 (49.5) 143,577 (47.3) Race NWH 211,311 (79.4) 226,924 (74.8) p< 0.001 NHB 30,526 (11.5) 37,611 (12.4) Hispanic 12,799 (4.8) 21,018 (6.9) Other 11,473 (4.3) 17,997 (5.9) Income Less than $40,227 49,766 (19.6) 49,676 (19.1) p< 0.001 $40,227 - $50,353 57,193 (22.5) 57,874 (22.3) $50,354 - $63,332 59,329 (23.5) 60,291 (23.2) $63,333 or more 87,568 (34.5) 92,041 (35.4) Percent Without High School Degree 17.6% or more 54,980 (21.6) 58,975 (22.6) p< 0.001 10.9% - 17.5% 67,951 (26.7) 69,392 (26.6) 6.3% - 10.8% 71,875 (28.3) 71,563 (27.5) Less than 6.3% 59,561 (23.4) 60,463 (23.2) Insurance Private 103,997 (39.1) 119,317 (39.3) p< 0.001 Medicaid 11,495 (4.3) 24,050 (8.0) Medicare 141,713 (53.3) 150,794 (49.7) Non-Insured 8,904 (3.3) 9,389 (3.0) Residence Location Metropolitan 218,379 (84.6) 251,012 (84.6) p< 0.001 Urban 34,764 (13.5) 40,309 (13.6) Rural 5,062 (2.0) 5,248 (1.8) Treatment Facility Community Cancer Program 25,022 (9.4) 26,467 (8.7) p< 0.001 Comprehensive Community Cancer Program 114,751 (43.1) 123,506 (40.7) Academic Program 69,335 (26.1) 91,285 (30.1) Integrated Network Cancer Program 57,001 (21.4) 62,292 (20.5) Charlson-Deyo Score 0 186,579 (70.1) 217,758 (71.7) p< 0.001 1 56,325 (21.2) 52,888 (17.4) 2 16,160 (6.1) 17,727 (5.8) >3 7,045 (2.6) 15,177 (5.0) Stage at Diagnosis 0 18,376 (6.9) 14,210 (4.7) p< 0.001 I 60,846 (22.9) 64,322 (22.2) II 66,828 (25.1) 72,303 (23.8) III 68,524 (25.8) 83,346 (27.5) IV 51,535 (19.4) 69,369 (21.9)