Abstract A125: Effects of Medicaid managed care on cancer staging: Evidence from Pennsylvania's mandatory Medicaid managed care program
Authors: Kwon Youngmin , Degenholtz Howard B. , Jacobs Bruce L. , Roberts Eric T. , Sabik Lindsay M. 
Published: December 2023

Introduction: Cancer contributes disproportionately to the disease burden among adult Medicaid beneficiaries, underscoring a need for early cancer detection to improve cancer outcomes. One policy development within Medicaid that may influence the timeliness of cancer detection is the use of managed care. Medicaid managed care (MMC) programs may promote early-stage diagnosis through their emphasis on care coordination, disease screening, and primary care management. However, little research has examined the impact of MMC and cancer staging. Therefore, we estimated the effects of implementing mandatory MMC on early vs. late-stage diagnosis among incident cancer cases insured by Medicaid in Pennsylvania. Methods: We included non-elderly adults aged 21 to 64 diagnosed with solid tumors in the Pennsylvania cancer registry (2010-2018). To ascertain insurance and MMC status, we linked the sample to their inpatient/outpatient hospital discharge records (containing payer information for the visit) within one month of diagnosis. We leveraged a natural experiment arising from county-level variation in the implementation of a mandatory MMC program in Pennsylvania. Using a stacked difference-in-differences (DD) design to account for staggered treatment timing, we analyzed changes in the stage of diagnosis among incident cancer cases in counties that newly transitioned to mandatory MMC in 2012/2013 (“treated”), before and after the transition. We compared changes in these treated counties to contemporaneous changes among counties that had mandatory MMC in operation since 1997 (“controls”). We estimated incident case-level linear probability DD models and controlled for patient demographics (age, sex, race/ethnicity, rurality, and area deprivation index), county-level healthcare resources (constructed using the Area Resources Files), and county- and year-quarter-by-stack fixed effects. Results: We found a significant reduction in late-stage diagnosis of 3.9 percentage-points, or pp (95% CI: -7.2, -0.5; P = .023; baseline mean: 55.9%) in the treated counties vs. control counties, before and after the transition. The effect of mandatory MMC were driven by a greater reduction in late-stage diagnosis in screening-amenable cancer cases (DD: -5.5 pp; 95% CI: -10.4, -0.6; P =.027), especially breast and cervical cancer cases (DD: -8.9, 95% CI; -16.8, -0.9, P = .029). Conclusions: Mandatory MMC was associated with a reduced probability of late-stage diagnosis, particularly for screening-amenable cancers, suggesting that care coordination and primary care management may contribute to early detection of cancer in Medicaid. However, late-stage diagnosis was still highly prevalent among Medicaid beneficiaries, both before and after the transition to mandatory MMC. Medicaid programs and managed care organizations should continue to carefully monitor cancer screening and design strategies to reduce barriers to screening. 

Citation Format: Youngmin Kwon, Howard B. Degenholtz, Bruce L. Jacobs, Eric T. Roberts, Lindsay M. Sabik. Effects of Medicaid managed care on cancer staging: Evidence from Pennsylvania's mandatory Medicaid managed care program [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr A125.