Role of statins in delirium prevention in critical ill and cardiac surgery patients: A systematic review and meta-analysis

Background: The data evaluating the role of statins in delirium prevention in the intensive care unit are conflicting and limited. Methods: We performed a systematic review and meta-analysis of literature from 1975 to 2015. All English language adult studies evaluating delirium incidence in statin and statin nonusers were included and studies without a control group were excluded. Mantel-Haenszel model was used to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs). Statistical significance was defined as CI not including unity and P value less than .05. Results: Of a total 57 identified studies, 6 were included. The studies showed high heterogeneity (I-2=73%) for all and moderate for cardiac surgery studies (I-2=55%). Of 289 773 patients, statins were used in 22 292 (7.7%). Cardiac surgery was performed in 4382 (1.5%) patients and 2321 (53.0%) used statins. Delirium was noted in 710 (3.2%) and 3478 (1.3%) of the patients in the statin and nonstatin groups, respectively, with no difference between groups in the total cohort (RR, 1.05 [95% CI, 0.85-1.29]; P=.56) or in cardiac surgery patients (RR, 1.03 [95% CI, 0.68-1.56]; P=.89). Conclusions: In critically ill and cardiac surgery patients, this meta-analysis did not show a benefit with statin therapy in the prevention of delirium. (C) 2016 Elsevier Inc. All rights reserved.