Statin Use and the Risk of Surgical Site Infections in Elderly Patients Undergoing Elective Surgery

Objective: To examine whether preoperative statin use is associated with a reduced risk of surgical site infections. Design, Setting, and Patients: Population-based retrospective cohort study of all elderly patients undergoing elective surgery in Ontario from April 1, 1992, through March 31, 2006. Preoperative statin use was identified using province wide pharmacy records. Procedure and patient characteristics were derived from hospital and physician claims databases within Canada's single-payer universal health care system. Main Outcome Measure: The 30-day risk of surgical site infection was derived from the initial admission, outpatient consultations, and hospital readmissions. Results: The cohort included 469 349 distinct elderly patients undergoing elective surgery, of whom 68 387 (14.6%) were statin users. The primary analysis included 53 565 statin users matched to 53 565 statin nonusers undergoing the same procedure in the same hospital by the same surgeon. Unadjusted analysis revealed a slight increase in the risk of surgical site infection among statin users compared with nonusers (8.9% vs 8.7%; P<.001), which disappeared after adjustment for demographics, health care utilization variables, comorbidities, and concurrent medication therapy (odds ratio, 1.00; 95% confidence interval, 0.95-1.04; P=.85). A similar lack of association was seen when matching was extended to include propensity scores (odds ratio, 0.99; 95% confidence interval, 0.94-1.05; P=.82). The lack of association persisted across pharmacologic, patient, and procedure subgroups. Conclusions: Statin use is not associated with an altered risk of surgical site infection. Prevention efforts should be directed toward other evidence-based strategies.