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Updated: Jun 13, 2026
A Mouse Model of Orthopedic Surgery to Study Postoperative Cognitive Dysfunction and Tissue Regeneration
Published on: February 27, 2018
Association between age and postoperative delirium after hip or knee replacement: a secondary analysis of a publicly
Shunzhong Jing1, Liping Jiang2, Anyuan Liu3
1Department of Anesthesiology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
Background:
Age is a well-established risk factor for postoperative delirium (POD), but its independent association with POD in older patients undergoing joint replacement warrants further clarification. We examined the association between age and POD in a publicly available arthroplasty dataset.
Methods:
This retrospective secondary analysis included 269 patients aged 65 years or older who underwent hip or knee replacement. POD was diagnosed within 5 days after surgery according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria and daily bedside assessment using the Confusion Assessment Method (CAM). Univariable and multivariable logistic regression models were used to evaluate the association between age and POD. Adjusted analyses included parsimonious and extended models, and Firth penalized logistic regression was performed as a robustness analysis. As the dataset contained no missing values for the outcome or retained covariates, no imputation was required. A generalized additive model (GAM) was used as an exploratory tool to visualize the shape of the association.
Results:
Among the 269 patients, 62 (23.0%) developed POD. In univariable analysis, increasing age was associated with higher odds of POD (odds ratio [OR] 1.139 per 1-year increase, 95% confidence interval [CI] 1.089-1.197; P < 0.001). This association remained stable in the parsimonious adjusted model (OR 1.133, 95% CI 1.073-1.202; P < 0.001), the extended adjusted model (OR 1.134, 95% CI 1.074-1.204; P < 0.001), and Firth penalized logistic regression (OR 1.126, 95% CI 1.068-1.193; P < 0.001). Exploratory smoothing suggested that the adjusted predicted probability of POD generally increased with age across the observed range. The main logistic regression models showed acceptable calibration according to the Hosmer-Lemeshow goodness-of-fit test.
Conclusions:
In older patients undergoing hip or knee replacement, increasing age was independently and robustly associated with POD across multiple analytic approaches. These findings support the use of age as an important factor in perioperative POD risk stratification, while highlighting the need for future studies with richer geriatric phenotyping to address residual confounding.
