Impact of Prefracture Cognitive Impairment and Postoperative Delirium on Recovery after Hip Fracture Surgery

Abstract

Objectives: This study aimed to examine the impact of prefracture cognitive impairment (CI) severity and postoperative delirium on recovery after hip fracture surgery in older patients.

Design: Prospective study with a 1-year follow-up.

Setting and participants: We included 355 patients aged ≥80 years from 2 acute hospitals in Japan.

Methods: Barthel Index (BI) ambulation scores were assessed prefracture and at 1, 3, 6, and 12 months postoperatively. The score at each time point minus the prefracture score was used as the ambulation recovery variable. The 21-item Dementia Assessment Sheet for the Community-based Care System (DASC-21) and Confusion Assessment Method were used to assess CI severity and delirium, respectively. The impacts of CI severity and delirium on recovery at 1 month and by 12 months postoperatively were examined. Linear multiple regression and linear mixed effects models were used.

Results: BI ambulation scores remained the same or improved from prefracture levels in 26.8%, 34.4%, 33.0%, and 30.4% of patients at 1, 3, 6, and 12 months, respectively. Ten patients (2.8%) had fall-related hip fractures, 20 (5.6%) were rehospitalized, and 43 (12.1%) died during this period. Although DASC-21 CI severity significantly affected the recovery both at 1 month and by 12 months postoperatively [standardized β (Stdβ) = -0.39, P < .0001, and Stdβ = -0.37, P < .0001, respectively], delirium did not. Other variables affecting recovery by 12 months postoperatively included prefracture BI ambulation scores, Mini Mental State Examination scores, age, fracture type, place of residence, and time.

Conclusions and implications: Postoperative ambulation recovery, excluding the effect of death and other poor outcomes, is influenced by prefracture CI severity, and the presence of delirium itself may not be the moderating variable. These results emphasize the importance of treatment planning based on prefracture CI severity and indicate that assessments such as the DASC-21 may be useful in implementing such a plan.

Keywords: Cognitive impairment; delirium; hip fracture.