Depression as a predictor of postoperative delirium after cardiac surgery: a systematic review and meta-analysis

OBJECTIVES: Depression is common in patients with cardiac disease. The importance of preoperative depression for development of postoperative delirium (POD) following cardiac surgery is not well known. The aim is to provide a summary estimate of depression as a predictor of POD following cardiac surgery. METHODS: Systematic search of MEDLINE, EMBASE, Cochrane Library, Web of Science Core Collection and Psycinfo (Ovid) was performed from inception to October 2019, including cohort studies reporting odds ratios (ORs) and 95% confidence intervals (CIs) for POD following cardiac surgery in patients with preoperative depression compared to patients without depression. ORs and 95% CIs for POD were calculated using random-effects meta-analyses. Subgroup and sensitivity analyses were performed. RESULTS: Seven studies were included with a combined study population of 2066 patients. The pooled prevalence of POD in the combined study population was 26% and preoperative depression was present in similar to 9% of the total study population. All studies showed a positive association between preoperative depression and POD; and in 5 studies, the association was statistically significant. Patients with depression had a pooled OR of 2.31 (95% CI 1.37-3.90) for POD. CONCLUSIONS: This systematic review and meta-analysis confirm the findings that the previous association between preoperative depression and increased risk for developing POD reported for other patient groups is found also in cardiac surgery. Depression screening prior to cardiac surgery may be effective in identifying patients at higher risk for POD.