Objective The purpose of this study was to systematically analyze the risk factors for post-operative delirium (PD) in elderly patients in an effort to provide a basis for developing relevant clinical interventions in China.

Methods All published studies focusing on the risk factors for PD among elderly patients in Wanfant Data, China National Knowledge Infrastructure (CNKI), and VIP were collected according to the inclusion and exclusion criteria of this study. A meta-analysis was performed on case-control studies using RevMan5.2 software, and the incidence of PD risk factors was calculated among case series.

Results Sixteen studies, including 8 case-control studies and 8 case series, were included in the current study. There were 353 cases and 2008 controls in the case-control studies. The pooled odds ratios (95% CI) of PD risk factors were as follows: hypoxemia, 2.58 (1.59~4.18); pulmonary infection, 4.51 (2.23∼9.13); hypertension, 2.16 (1.20∼3.89); coronary heart disease, 1.50 (0.82∼2.73); post-operative pain, 3.18 (1.63∼6.20); general anesthesia, 3.64 (0.94∼14.11); operative time, 1.70 (0.79∼3.66); and senility, 0.52 (−0.25∼1.29). The meta-analysis showed that hypoxemia, pulmonary infection, hypertension, coronary heart disease, post-operative pain, general anesthesia, operative time, and senility were significant risk factors for PD. There were 404 cases in the case series, and the incidence of hypoxemia, hypertension, general anesthesia, diabetes mellitus, senility, coronary heart disease, pulmonary infection, and cerebrovascular disease was 62.62%, 55.90%, 33.7%, 24.8%, 16.58%, 15.3%, 13.9%, and 12.1%, respectively, which was much higher than other risk factors.

Conclusion Senility, hypertension, coronary heart disease, diabetes mellitus, pulmonary infection, hypoxemia, post-operative pain, and general anesthesia are significant risk factors for PD among elderly Chinese patients.