Abstract B131: How do reversal rates vary among patients with colorectal cancer for which intestinal stoma was performed?
Authors: Hang Lillian , Henk Henry J 
Published: September 2020

Abstract
Background: Studies of colorectal cancer (CRC) patients have found patients in whom the intestinal stoma was performed consistently report more impairment and lower quality of life than their non-stoma counterparts. Where possible, the intention is to subsequently reverse the stoma (via stoma closure). The goal of this study is to examine disparities in stoma reversal (SR) rates among colorectal cancer patients who have health care insurance. Methods: This retrospective cohort study was conducted using medical claims and enrollment records from the OptumLabs Data Warehouse®, which includes commercial and Medicare Advantage (MA) enrollees representing a diverse mixture of ages, ethnicities and geographical regions across the United States. Eligible patients were required to have undergone intestinal ostomy (either colostomy or ileostomy) with an intestinal stoma between 2000 – 2017 as part of their CRC treatment and be enrolled for at least one year prior to and one year following the surgery. A Cox proportional hazard model was used to examine the relationship between patient demographics and clinical characteristics and the rate of SR. Patient demographics include age, sex, race, household income, and rurality. Comorbidity was measured using the Charlson Comorbidity Index score (CCI) excluding the two cancer categories. To further control for difference in health plan design and cost sharing, we included the patients’ health plan type (commercial or MA) and if the commercial enrollee was in a consumer driven health plan (i.e., high deductible). Results: We identified 13,633 individuals with colorectal cancer diagnosis between 2000 and 2017 who underwent either a colostomy or ileostomy in which the intestinal stoma was created. The overall SR rate was 16.4% with a median time to reversal of 6 months. The majorities of patients in our study are age 65+ (56%), male (52%), white (77%), and live in a metropolitan area (86%). Excluding cancer, the average CCI was 1.2 (sd=1.4) with 84% having CCI &lt; 2. The cohort had a median follow up enrollment period of 2.5 years. The majority of patient resided in a household with income less than $75K per year (59%). Prior to controlling for other factors, SR rates were found to be higher in males (19.5% vs 13.1%; p&lt;.001) and varying by race (p&lt;.001): non-Hispanic whites (21.48%), Hispanic (18.6%), Asian (16.7%) and non-Hispanic blacks (12.8%). Reversal rates ranged from 14.2% for those in households with annual income under $75K to 22.1% for those above $125K (p&lt;.001). However, after controlling for all factors, SR rates were only lower for females [HR=0.70; 95% CI=0.65, 0.77]) and African-American compared to White [HR=0.79; 95% CI=0.68, 0.90]). Household income, rurality and CCI were not found to be independently associated with varying SR. Conclusions: We find variation in SR rates by race and gender independent of age, health plan design, rurality and household income such that women and African Americans are less likely to receive SR.
Citation Format: Lillian Hang, Henry J Henk. How do reversal rates vary among patients with colorectal cancer for which intestinal stoma was performed? [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B131.