Effect of insurance status on mortality following surgical treatment of colorectal cancers in the United States

Healthcare disparities in colorectal cancer, driven by insurance status and socioeconomic factors, lead to delayed diagnoses and poor surgical outcomes. We sought to examine the impact of insurance status on presentation, treatment, and in-hospital mortality among CRC patients undergoing colectomy using the Nationwide Inpatient Sample (NIS) database. We included patients aged 18-65 years diagnosed with colon cancer and undergoing colectomy, as identified by ICD-9-CM codes. We classified them as those with private insurance, Medicaid, or no insurance during the period January 1, 2005, through December 31, 2014. The primary independent variable was insurance status, and the primary outcome was in-hospital postoperative death. Associations between this outcome and insurance status were analyzed using the Cox proportional hazard model, both in the full cohort as well as in a subset of patients with low comorbidity, with models stratified by hospitals to account for clustering effects from variations in access to care. The study cohort included 301,304 patients, of whom 238,158 (79.0%) were privately insured, 40,417 (13.4%) on Medicaid, and 22,729 (7.6%) were uninsured. Most patients were White (71.6%), followed by African American (12.6%), Hispanic (8.4%), Asian/Pacific Islander (3.8%), and Native American (0.5%). A total of 55.4% of cases took place in teaching hospitals. In the unadjusted analysis, the mortality rate for privately insured patients was 0.7% (95% CI 0.6-0.7%) compared with 2.1% for uninsured patients (95% CI 1.7-2.5%) and 1.5% for Medicaid recipients (95% CI 1.2-1.8%; p = 0.001). After adjusting for patient characteristics and stratifying by hospital in patients with low comorbidity, uninsured patients still had a higher risk of experiencing in-hospital death (HR, 1.60; 95% CI 1.24-2.07) compared with privately insured patients, while no significant disparity was found in Medicaid recipients (HR, 0.95; 95% CI 0.75-1.22). Uninsured patients undergoing colectomy for colon cancer experienced the highest in-hospital mortality, a disparity not fully explained by overall health differences. These findings underscore the critical role of insurance coverage in improving surgical outcomes and highlight the need for policy interventions to reduce mortality disparities.