Abstract PO-112: The contribution of co morbidities to health disparities of cancer patients in a vertically integrated healthcare system
Authors: Cooper Robert M. , Haque Reina , Chao Chun 
Published: January 2022

Abstract
Background: There are noted health disparities related to socioeconomic status and race in cancer patients across many cancer sites. The causes of the health disparities are multi factorial. These factors include access to health insurance, limitations of the care delivery system, as well as co morbidities and social determinants of health (SDH). This study looks to define the influence of co morbidities and SDH by studying insured patients being cared for in the same vertically integrated health care system. Methods We linked internal cancer Kaiser Permanente Southern California registry data for 153,270 patients diagnosed with invasive cancer from 2010-2018 and followed through 2020. The dataset was geocoded and patients were divided into quintiles based on presumed income related to census track. Outcomes included all cause mortality at the 1,3,5 years from diagnosis the overall mortality rate. We defined the health disparities related to race/ethnicity and SES in our overall population and by ten specific common cancer sites. We evaluated the interaction of race and SES on outcomes. Each patient was evaluated for comorbidities present at diagnosis and co morbidity burden was defined by the Elixhauser index score. We separately looked at individual modifiable comorbidities including, hypertension, diabetes mellitus, depression, smoking and obesity. We defined the prevalence of comorbidities by race/ethnicity and SES. We defined the effect of the individual co morbidities and Elixhauser score on overall outcomes. Using Cox proportional hazards model analyses we defined the impact of co morbidity burden and modifiable co morbidities on overall outcomes for the entire data set to better determine the contribution of comorbidities to disparities related to SES and define the social determinants of heath by race/ethnicity and SES. Results: Overall, Hispanics and Asian/PI had lower mortality at all outcomes points including 22% lower overall mortality then Whites and Blacks which had similar. Pts in the lower SES quintiles had higher overall mortality at all time points including a 25% increased mortality risk for bottom 4 quinitiles compared to the top quintile. We examined the health disparities of SES and parsed out the contribution of co morbidities defined by Elixhauser score each socioeconomic quintile showed that approximately 40% of the health disparity in the lower 2 quintiles related to SES can be attributed to differences in co morbidities and 60% explained by SDH. Conclusion: For an insured patient population cared for within the same medical system we were able to better isolate the health disparities related toSES and Race/ethnicity. We were then able to qualify the contributions of co morbidities and SDH to these observed heath disparities. We hope that these evaluations will add to our understanding of health disparities related to race/ethnicity and SES.
Citation Format: Robert M. Cooper, Reina Haque, Chun Chao. The contribution of co morbidities to health disparities of cancer patients in a vertically integrated healthcare system [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-112.