Health outcomes of statin users compared to non-users with Clostridium difficile infection

Background: Clostridium difficile infection (CDI) is the most common cause of nosocomial diarrhea, and the primary cause of healthcare-associated infections in the United States. Statins have beneficial effects independent of their lipid-lowering effects; these pleiotropic effects may include anti-inflammatory and immunomodulatory activity. The potential role for statins in CDI is unique in that both the cholesterol-lowering and pleiotropic effects of statins could lead to improvements in clinical response for patients with CDI.

Rationale: Limited data currently exist in the literature on the outcomes of statin users who develop CDI compared with non-users. The primary objective of this study was to compare CDI health outcomes in statin users and non-users in a national cohort of patients from a single-payer health system.

Methods: This was a longitudinal, retrospective cohort study of all adult CDI patients receiving care from the Veterans Health Administration. Patients were divided into two groups based on statin exposure prior to and during the first CDI encounter. For the primary analysis, we created a propensity score-matched cohort to account for variables associated with indications for statin use. Once the matched cohort was derived, additional variables known to impact CDI outcomes were entered into a multivariable logistic regression model in order to determine the risk of individual CDI outcomes.

Results: CDI outcomes were evaluated for statin users and non-users before and after propensity score-matching. In the unmatched cohort, statin use was significantly associated with reduced risk of 30-day mortality (aOR 0.60, 95% CI 0.36-1.00, p=0.0478). In the matched cohort, statin use remained significantly associated with a reduced risk of 30-day mortality (aOR 0.45, 95% CI 0.23-0.88, p=0.0198). No significant trends were found for inpatient mortality, 60-day recurrence, and severe or complicated CDI.

Conclusion: This is the largest study comparing CDI health outcomes among statin users and non-users. Statin users were found to have significantly reduced 30-day mortality in both an unmatched and matched patient cohort compared to non-users. While these data support previous findings reported in the literature, no change in routine care of CDI patients can be recommended at this time.