Associations Between Colorectal Cancer Screening and Glycemic Control in People With Diabetes, Boston, Massachusetts, 2005-2010

INTRODUCTION: Recent studies indicate an increased risk of colorectal cancer in people with diabetes. However, people with diabetes may have lower colorectal cancer screening rates than people without diabetes. Few data are available regarding factors associated with lack of screening for people with diabetes. Our objective was to describe factors associated with lack of timely colorectal cancer screening in people with diabetes. METHODS: We examined an electronic medical record database with more than 6,000 patients aged 50 years or older who had diabetes and were seen in a large hospital system in Boston, Massachusetts. We compared patients who had received timely colorectal cancer screening with those who had not on several variables, including glycemic control, expressed as average hemoglobin A1c (HbA1c). Bivariate analyses were performed using χ(2) and t tests for means when applicable. Logistic regression was used to determine the independent association of variables with lack of screening. RESULTS: Patients with poor glycemic control (average HbA1c >8.5%) were more likely not to have been screened for colorectal cancer than those with good glycemic control, even after adjusting for the number of primary care visits. Patients with fewer than 20 primary care visits in 5 years were more likely not to have been screened than those with more visits. CONCLUSION: Glycemic control appears to be independently associated with the likelihood of colorectal cancer screening. People with poorly controlled diabetes should be targeted in future research and individual patient care.