Colorectal cancer readmissions: Identifying high-risk patients and drivers of cost.

Abstract

52 Background: Colorectal cancer was the second highest contributor to treatment costs in 2020, accounting for 11.6% of all cancer-related expenditures according to the CDC. Risk factors include excess body weight, smoking, alcohol use, and demographic variables such as age, sex, and race. We aimed to investigate risk factors for readmission, evaluate the impact of readmissions on healthcare utilization, and identify the most common causes. Methods: Patients admitted in 2022 were identified from the Nationwide Readmissions Database and categorized into two groups using ICD-10 codes: colorectal cancer (index admission), colorectal cancer with readmission within 90 days. Readmitted and non-readmitted patients were compared. Multivariate regression adjusted for confounders. Results: The study population included 47,457 index admissions and 8,303 readmissions within 90 days. Mean age was 67.3 years in the index group and 68.2 in the readmission group. Mean length of stay and hospital costs were 6.49 days and $27,399 in the index group versus 7.55 days and $28,704 in the readmission group. Baseline characteristics and comorbidities are summarized in the table. The most frequent cause of readmission was sepsis, followed by postprocedural complications and acute kidney injury. Other common causes included infections following a procedure, intestinal obstruction/ileus, and colostomy-related care. Less frequent but notable causes were pulmonary embolism, toxic gastroenteritis/colitis, COVID-19, hypertensive heart and chronic kidney disease with heart failure, C. difficile enterocolitis, sepsis due to E. coli , and peritoneal abscess. On multivariate analysis, iron deficiency anemia (HR 1.35, p<0.001), thrombosis (HR 1.36, p<0.001), ACS (HR 1.70, p=0.022), AKI (HR 1.28, p<0.001), CHF (HR 1.23, p=0.016), and alcohol abuse (HR 1.20, p=0.053) increased readmission risk. Smoking, cirrhosis, DM, cerebrovascular accident, obesity, and CKD were not significant. Conclusions: Readmission within 90 days in colorectal cancer patients was associated with greater healthcare utilization, including longer stay and higher costs. Sepsis and postprocedural complications were the most frequent causes, while iron deficiency anemia, thrombosis, ACS, AKI, CHF, and alcohol abuse were significant predictors. These findings highlight the need to identify high-risk patients and implement targeted strategies to reduce readmissions and costs. Baseline Characteristics and Comorbidities Index Admission Readmission p value Iron Deficiency Anemia 16.9% 24.59% < 0.001 Thrombosis 3.15% 5.72% < 0.001 CKD 11.38% 16.18% < 0.001 CHF 7.87% 13.12% < 0.001 Diabetes Mellitus 23.36% 26.42% 0.0001 Alcohol Abuse 1.9% 2.68% 0.0014 ACS 0.26% 0.62% 0.0010 COPD 7.03% 9.75% <0.001 Expected primary payer <0.001 -Medicare 56.88% 61.62% -Medicaid 7.34% 10.02% -Private insurance 31.7% 24.02%