Frailty is a reduced capacity to recover from a physiologically stressful event. It is well established that preoperative frailty is associated with poor postoperative outcomes, but it is unclear if this includes cognitive decline following anesthesia and surgery. This retrospective observational study was a secondary analysis of data from a previous study (the Anaesthesia, Cognition, Evaluation [ACE] study). We aimed to identify if preoperative frailty or prefrailty is associated with preoperative and postoperative neurocognitive disorders or postoperative cognitive dysfunction.
The ACE study enrolled 300 participants aged ≥60 scheduled for elective total hip joint replacement and who underwent a full neuropsychological assessment at baseline and 3 and 12 months postoperatively. We applied patient data to 2 frailty models; both were based on an accumulation of deficits score: the reported Edmonton frail scale (REFS) and the comprehensive geriatric assessment-frailty index (CGA-FI) based on the comprehensive geriatric assessment. We calculated these 2 scores using baseline data collected from the medical history, demographic and clinical data as well as self-reported questionnaires. Some items on the REFS (3 of 18 or 17%) and the CGA-FI (37 of 51 or 27%) did not have an equivalent item in the ACE data.
The mean age (standard deviation [SD]) was 70.1 years (6.6) with more women (197 [66%]). Using the REFS model, 40 of 300 (13.3%) patients were classified as vulnerable, mild, or moderately frail. Using the CGA-FI model, 69 of 300 (23%) were classified as intermediate or high frailty. The REFS and the CGA-FI were strongly correlated (r = 0.75; P < .01) with 34 of 300 (11%) meeting criteria for frailty by both the REFS and the CGA-FI.
Frailty or prefrailty was associated with cognitive decline at 3 and 12 months using the REFS (odds ratio [OR], 1.51, 95% confidence interval [CI], 1.02–2.23 and OR, 2.00, 95% CI, 1.26–3.17, respectively) after adjusting for baseline mini-mental state examination (MMSE), smoking, hypertension, diabetes, history of acute myocardial infarction (AMI), and estimated intelligence quotient (IQ). Age did not modify this association. After adjusting for multiple comparisons, 3-month cognitive decline was no longer significantly associated with baseline frailty.
This retrospective analysis demonstrates an association between baseline frailty and postoperative neurocognitive disorders, particularly using the more extensive REFS scoring method. This supports preoperative screening for frailty to risk-stratify patients, and identify and implement preventive strategies and to improve postoperative outcomes for older individuals.