The association of a vertically integrated health system with colon cancer stage at presentation.

156 Background: Kaiser Permanente Southern California (KPSC) offers healthcare screening, treatment, and medications through a singular vertically integrated coordinated care delivery model. This structure may benefit in identifying patients at earlier stages of cancer, especially for those cancer types with early preventive screening such as colon cancer. Methods: We examined an insured Southern California cohort of 23,749 patients diagnosed with invasive colon cancer between Jan 1, 2015 and Dec 31, 2020 provided by the state SEER Cancer Registry. Stage at diagnosis provided was SEER summary stage in which patients were defined as having local disease or advanced (regional or metastatic) disease. We used geocoded socioeconomic status, race/ethnicity, and hospital of diagnosis as independent variables. For hospital of diagnosis, patients were divided into those diagnosed in KPSC Hospitals or not. The prevalence of colon cancer disease was determined and multivariate logistic regression was used to determine the adjusted odd ratios of being diagnosed with local disease within KPSC versus outside KPSC. Results: Compared to patients not diagnosed in KPSC patients diagnosed in KPSC were more likely to be diagnosed with local colon cancer disease OR 1.42 (95% Confidence Intervals 1.34, 1.51). The interaction of KPSC colon cancer diagnosis and SES quintile in the total cohort showed that the odds of being diagnosed with local colon cancer was significantly higher in all SES quintiles for KPSC patients and increasingly pronounced in the lower SES quintiles. Lowest SES 1.53 (1.32, 1.78), lower-middle SES 1.49 (1.31, 1.69), middle SES 1.50 (1.33, 1.70), upper-middle SES 1.11 (1.08, 1.14), and highest SES 1.21 (1.04, 1.41). The interaction of KPSC colon cancer diagnosis and race/ethnicity in the total cohort showed significantly higher odds of being diagnosed with local colon cancer for non-Hispanic White 1.33 (1.22, 1.45), Asian/Pacific Islander 1.69 (1.43, 2.00), Non-Hispanic Black 1.42 (1.17, 1.72), and Hispanic patients 1.46 (1.31, 1.63) compared to colon cancer patients diagnosed in non-KPSC hospitals. Conclusions: Insured patients in KPSC are more likely to be diagnosed with local colon cancer disease than in non-KPSC health systems. This association may be assisted by an established preventive colon cancer screening program. This association appeared strongest among patients in lower SES quintiles and in White, Asian, Black and Hispanic patients. More investigation is needed to examine how vertically integrated coordinated care models may assist in diagnosing invasive colon cancer at an earlier stage.