Accuracy of the Clinical Frailty Scale for perioperative frailty screening: a prospective observational study

Abstract

Purpose: Perioperative frailty increases postoperative complications, mortality, and new functional dependence. Despite this, routine perioperative frailty screening is not widespread. We aimed to assess the accuracy of the Clinical Frailty Scale (CFS) as a screening tool prior to anesthesia, and to determine which health domains are affected by frailty. Methods: In a prospective, single-centre observational study, we enrolled 218 patients aged ≥ 65 yr undergoing elective and emergency surgery. The screening performance of the CFS was compared with the Edmonton Frail Scale, including the effect in individual frailty domains, and outcomes including discharge location and mortality. Results: The median [interquartile range] age of the enrolled subjects was 74 [69–80] yr and 24% of the patients were frail. The CFS and Edmonton scales were highly correlated (Spearman correlation coefficient, 0.81; 95% confidence interval [CI], 0.77 to 0.86), and in substantial agreement (kappa coefficient, 0.76; 95% CI, 0.70 to 0.81), with an area under the receiver operating characteristic curve of 0.91 (95% CI, 0.86 to 0.94) indicating excellent discrimination for the CFS in predicting frailty status based on the Edmonton scale. Frail patients had higher 30-day mortality (odds ratio, 5.26; 95% CI, 1.28 to 21.62), and were less likely to be discharged home. Frail patients had poorer health throughout frailty domains, including functional dependence (42% of frail vs 4% of non-frail patients; P < 0.001), malnutrition (48% vs 19%, P < 0.001), and poor physical performance (47% vs 7%, P < 0.001). Conclusion: The CFS is a valid and accurate tool to screen for perioperative frailty, which encompasses the spectrum of health-related domains.