Potential beneficial effects of long-term aspirin use on the prevalence of colorectal cancer: a population-based study of the US Nationwide Inpatient Sample.

Purpose: Whether long-term aspirin usage is associated with colorectal cancer (CRC) risk needs more evidence. The study evaluated the association between long-term aspirin use and prevalence of CRC in a large, nationally representative database. Methods: Hospitalized patients aged ≥ 50 years during 2018 were identified in the United States (US) National Inpatient Sample (NIS). Patients without complete information of age, sex, race, income, and insurance status were excluded, as well as those with inflammatory bowel disease (IBD) or malignancies other than CRC. Propensity score matching (PSM) was applied to balance the characteristics between patients with and without long-term aspirin use. Logistic regressions were performed to determine the relationship between long-term aspirin use and the presence of CRC. CRC and aspirin use were identified through the administrative International Classification of Diseases (ICD) codes. Results: Data from 3,490,226 patients were included, in which 688,018 (19.7%) had a record of long-term aspirin use. After 1:1 PSM, there remained 1,376,006 patients, representing 6,880,029 individuals in the US after weighting. After adjusting for confounders, long-term aspirin use was significantly associated with lower CRC odds (adjusted odds ratio [aOR] = 0.64, 95% confidence interval [CI] 0.62, 0.67). This association was not changed when stratified by age, sex, race, body mass index (BMI), and smoking. Conclusions: From a national inpatient dataset, US adults ≥ 50 years on long-term aspirin are less likely to have CRC, regardless of age, sex, race, BMI, and smoking status. [ABSTRACT FROM AUTHOR]