Date of Award

January 2020

Document Type

Thesis

Degree Name

Medical Doctor (MD)

Department

Medicine

First Advisor

James B. Yu

Second Advisor

Shari Damast

Abstract

In the current national debate regarding Medicaid expansion, understanding how insurance is associated with racial and socioeconomic disparities in cancer outcomes has broad policy implications. Using the Surveillance, Epidemiology, and End Results Program, we sought to evaluate sociodemographic disparities in insurance coverage among non-elderly adults after Affordable Care Act (ACA) implementation. We first examined the association between insurance (Medicaid vs. private) and receipt of therapy and cancer-specific outcomes among men diagnosed with prostate cancer from 2007-2014. To better understand various state approaches to Medicaid expansion, we further analyzed associations between ACA implementation and uninsured rates among patients diagnosed with a common cancer (prostate, breast, or thoracic) from 2010-2014, stratified by race (black, white) and income (stratified at 138% federal poverty line [FPL]).

Significant interactions between race and insurance status indicate insurance had more-than-additive association with race. Among privately insured men with prostate cancer, disparities in prostate cancer-specific mortality (adjusted odds ratio (AOR) 1.2, 95% confidence interval (CI) 1.03-1.40; P=0.019) and presentation with metastatic disease (AOR 1.13, 95% CI 1.06-1.21; P<0.001) were observed. No disparities were observed among Medicaid patients with prostate cancer in regard to prostate cancer-specific mortality (AOR 0.79, 95% CI 0.52-1.20; P=0.272) and metastatic disease (AOR 0.91, 95% CI 0.80-1.03; P=0.139). Yet, men diagnosed with prostate cancer with Medicaid insurance were more likely to present with metastatic disease (AOR 4.27, 95% CI 4.01-4.55), less likely to receive definitive treatment (AOR 0.67, 95% CI 0.62-0.71) and had increased prostate cancer-specific mortality (PCSM; adjusted hazard ratio (AHR) 1.83, 95% CI 1.50-2.24), regardless of race.

Among all patients diagnosed with a common cancer, uninsured rates declined after ACA implementation, with the greatest rate reductions associated with traditional Medicaid expansion (Pinteraction<0.001). Racial disparities in insurance coverage were eliminated with traditional Medicaid expansion where the uninsured rate went from 10.0% to 0.95% among black patients (AORpre-aca1.52 to AORpost-aca0.47) but persisted with other state approaches (AORpre-aca 1.15 to AORpost-aca1.12) [Pinteraction=0.002]. Furthermore, socioeconomic coverage gaps were eliminated with traditional Medicaid expansion, where the uninsured rate went from 8.4% to 1.4% among low-income (<138% FPL) patients, but not with other state approaches [Pinteraction<0.001].

Racial disparities in prostate cancer outcomes are observed in heterogeneous privately insured cohorts, while reduced in Medicaid. We also note that traditional Medicaid expansion was associated with the elimination of racial and socioeconomic insurance coverage gaps. Still, Medicaid outcomes need to be improved overall. Whether the equality in outcomes for Medicaid is due to white and African-American patients doing “equally poorly” or “equally well” is unclear. These results highlight the potential benefits and challenges of the ACA and its provisions and could instruct ongoing policy.

Comments

This thesis is restricted to Yale network users only. This thesis is permanently embargoed from public release.

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