National disparities in colorectal cancer screening in patients with comorbid conditions: an analysis of the Behavioral Risk Factor Surveillance System

Context: Each year, approximately 53,200 people die in the U.S. from colorectal cancer (CRC), indicating a need to increase screening efforts. Some studies have suggested mammography use is higher in patients with comorbid conditions, a reflection of increased follow up. Another study found that patients with obesity were less likely to be screened for CRC than nonobese patients. However, no study has assessed the impact of multiple comorbidities on CRC screening. Objectives: To analyze CRC screening rates in patients with comorbidities compared with healthy patients, and to assess whether the number of comorbid diagnoses impacted screening rates. Methods: A cross sectional analysis of patients who received CRC screening was performed using the 2018 and 2019 Behavioral Risk Factor Surveillance System (BRFSS). Respondents were classified as having had CRC screening if they answered "yes" to either of the following: "Have you ever had a blood stool test?" or "Have you ever had a sigmoidoscopy/colonoscopy?" Respondents younger than age 50 were excluded. A weighted multivariate logistic regression model was constructed to determine adjusted risk ratios (ARR). Confidence intervals (CI) were reported at 95%. Results: We identified 279,784 respondents who met inclusion criteria. Of those, 79.7% (sample n=222,879; population N=46,304,360) of respondents had received CRC screening. Patients with diabetes, hypertension, skin cancer, chronic obstructive pulmonary disease (COPD), arthritis, depression, and chronic kidney disease were significantly more likely to be screened than those without comorbidities. There was no statistically significant difference in screening rates between patients with and without cardiovascular disease. Compared with patients with zero comorbidities, those with one were significantly more likely to receive screening (ARR, 1.11; CI, 1.09-1.12) as were those with two to four (ARR, 1.2; CI, 1.18-1.22). Patients with five or more comorbidities were significantly less likely to be screened than those with two to four (ARR, 1.12; CI, 1.1-1.14). Conclusions: Patients with one or more comorbidities were more likely to be screened than those without comorbidities, but those with five or more conditions were less likely to be screened than patients with two to four conditions. This indicates that physicians may be more fatigued and less likely to recommend CRC screening to patients with many comorbidities compared with patients diagnosed with only a few conditions. The results of this study add to the literature by identifying an interaction between the number of comorbidities and likelihood of being screened for CRC.