Predictors of Postoperative Delirium in Elderly Patients Following Total Hip and Knee Arthroplasty: A Systematic Review and Meta‑Analysis

Background: Postoperative delirium (POD) is widely reported as a very common postoperative complication following total joint arthroplasty (TJA) of the hip and knee in elderly patients, leading to a variety of adverse effects. We sought to investigate predictors of delirium after TJA. Methods: PubMed, EMBASE, Cochrane Library, and Web of Science were searched up to May 2020 for studies examining POD following TJA in elderly patients. Pooled odds ratio (OR) and mean difference (MD) of those who experienced delirium compared to those who did not were calculated for each variable. The Newcastle-Ottawa Scale (NOS) was used for the study quality evaluation. Results: Fifteen studies with 31 potential factors were included in the meta-analysis. In the primary analysis, 9 factors were associated with POD, comprising advanced age (MD 3.81; 95% confidence interval (CI) 1.80–5.83), dementia (OR 24.85; 95% CI 7.26–85.02), hypertension (OR 2.26; 95% CI 1.31–3.89), diabetes (OR 2.02; 95% CI 1.15–3.55), stroke (OR 14.61; 95% CI 5.26–40.55), psychiatric illness (OR 2.72; 95% CI 1.45–5.08), use of sedative-hypnotics (OR 6.42; 95% CI 2.53–16.27), lower preoperative levels of hemoglobin (MD −0.56; 95% CI −0.89–−0.22), and lower preoperative mini-mental state examination score (MD −0.40; 95% CI −0.69–−0.12). Twelve studies were included in the systematic review, of which 24 factors were additionally correlated with POD using single studies. Conclusions: We identified predictors of POD in elderly patients following TJA. These findings may be used to identify patients with a high risk of delirium who are most likely to benefit from postoperative recovery.