Abstract PO-210: Healthcare disparities in melanoma overall survival evaluated by race/ethnicity and socioeconomic status and the impact of integrated healthcare on an insured population
Authors: Rosenthal Amanda H. , Reddy Shivani , Kim Christina N. , Cooper Robert M. , Haque Reina 
Published: January 2022

Background: The objective of this study was to quantify the influence of race/ethnicity and socioeconomic status (SES) on overall mortality within an insured population of patients diagnosed with melanoma in Southern California. Specifically, we compared outcomes between insured patients within the largest vertically integrated health care system in Southern California, Kaiser Permanente Southern California (KPSC), with insured patients diagnosed elsewhere. Methods: We identified adults (≥20 years old) diagnosed with Stage 0-IV melanoma from 1 January 2009 through 31 December 2014, followed through the end of 2017, from the California Cancer Registry. We compared overall mortality in those diagnosed within KPSC versus those with other private insurance (OPI). Main variables included race/ethnicity and SES based on 2010 Census data. Person-year (PY) mortality rates and 95% confidence intervals (CI) were calculated by race/ethnicity and SES. Multivariable-adjusted hazard ratios (HR) for the association between all-cause mortality and race/ethnicity and SES were estimated using Cox proportional hazards models. Results: A total of 14,614 adults were diagnosed with melanoma in our cohort (KPSC: n=4,701; OPI: n=9,913). The total of number of all-cause deaths was 2,456 (KPSC: n=729; OPI: n=1,727). Mortality rates by race/ethnicity within KPSC and OPI did not reveal significant disparities. The poorest patients in KPSC (lowest, lower-middle, and middle SES groups) had statistically significant decreased mortality rates compared to those in OPI. For example, in the lowest SES, those in OPI had 38.7 additional deaths per 1000 PY compared to KPSC (KPSC Rate per 1000 PY: 57.7, 95% CI: 44.9-73.1; OPI Rate per 1000 PY: 96.4, 95% CI 80.9-113.9). Multivariable models demonstrated statistically significant increased mortality risk among the lowest (HR 1.70, 95% CI 1.43-2.02), lower-middle (HR 1.47, 9% CI 1.29-1.68), middle (HR 1.36, 95% CI 1.21-1.53), and upper-middle (HR 1.19, 95% CI 1.07-1.33) SES groups when compared to the highest SES group. This increased mortality risk among lower SES groups persisted when stratifying by KPSC and OPI. Although KPSC patients had a lower mortality risk across all SES groups compared to OPI, the difference was not statistically significant. For example, among the lowest SES, those in the OPI group had an overall mortality risk 80% greater than those of the highest SES (HR 1.80; 95% CI 1.47-2.22), while those in KPSC held risk only 47% greater (HR 1.47, 95% CI 1.09-2.00). Conclusions: While the existence of disparities in cancer survival are well established, our present study examined survival with respect to SES among two distinct populations of melanoma patients: insured patients within an integrated healthcare system and insured patients within a traditional model of healthcare. While racial/ethnic disparities are not observed in integrated healthcare systems such as KPSC, our findings underscore the persistence of socioeconomic disparities within an insured population, despite having access to care.

Citation Format: Amanda H. Rosenthal, Shivani Reddy, Christina N. Kim, Robert M. Cooper, Reina Haque. Healthcare disparities in melanoma overall survival evaluated by race/ethnicity and socioeconomic status and the impact of integrated healthcare on an insured population [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-210.