Objectives To estimate the possible relationship between statin use and the risk of healthcare facility onset Clostridium difficile.

Methods Patients over 18 years of age admitted to hospitals contributing data to the University HealthSystem Consortium between 2002 and 2009 were eligible. Patients with the ICD-9-CM code 008.45 who received a minimum 3-day course of either metronidazole or oral vancomycin on/after day 5 of admission were considered incident cases of C difficile infection. 31 472 incident cases of C difficile infection were identified and matched to five controls, on hospital, year/quarter of admission date, and age ±10 years (N=78 096). Patients who were administered one drug in the statin class (atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin or simvastatin) before the index date were considered to be exposed. Conditional logistic regression modelling provided adjusted odds ratios and 95% CI.

Results Compared with non-users, users of any drug within the statin class were 0.78 times less likely to develop C difficile infection in the hospital (95% CI 0.75 to 0.81) adjusting for potential confounders. Differences in estimates for specific statins were minimal. Niacin, fibrates and selective cholesterol absorption inhibitors showed no association with the risk of C difficile infection.

Conclusions Our data were consistent with a growing body of literature demonstrating a reduced risk of infections with statin use. Statins' pleiotropic properties may provide protection against C difficile infection.