Association between postoperative delirium and mortality in elderly patients undergoing hip fractures surgery: a meta-analysis

Abstract

Introduction: Postoperative delirium (POD) is a common complication in elderly surgical patients. Patients undergoing hip fractures surgery who are often characterized by advanced age could be particularly prone to suffering POD. We performed a meta-analysis to assess the association between POD and mortality in elderly patients undergoing hip fractures surgery. This meta-analysis included twenty-one cohort studies, and the pooled outcomes demonstrated that approximated one-fourth of patients undergoing hipfracture surgery would develop POD, and delirium increased the mortality in these patients.

Methods: We searched PubMed, Embase, Web of Science, and Scopus for studies that investigated the effect of POD on mortality in elderly patients undergoing hip fracture surgery. Two reviewers independently selected studies, assessed quality, and extracted data. Statistical analyses were performed by STATA 14.0 and RevMan 5.3. Risk ratios (RRs) with 95% confidence intervals (CIs) were derived using random or fixed-effects model.

Results: Twenty-one cohort studies enrolling a total of 6288 patients were included, and the pooled prevalence (95% CI) of POD was 28% (23-34%). POD was associated with an increase in perioperative mortality (30-day or in-hospital mortality) [12 studies, 3123 patients, relative risk (RR) (95% CI) 2.79 (1.97-3.93)], 6-month mortality [6 studies, 1673 patients, 2.51 (1.99-3.16)], 1-year mortality [6 studies, 1896 patients, 1.98 (1.62-2.41)], and more than 1-year mortality [8 studies, 1926 patients, 2.06 (1.60-2.64)].

Conclusions: Our meta-analysis demonstrated that approximated one-fourth of patients undergoing hip fracture surgery would develop POD, and delirium increased the short-term and long-term mortality in these patients.

Keywords: Delirium; Elderly; Hip fracture; Meta-analysis; Mortality.