Clinical Utility of Frailty Scales for the Prediction of Postoperative Complications. Systematic Review and Meta-Analysis

INTRODUCTION: Frailty can be defined as a biological syndrome of reduced reserve and resistance to stressful events. Evidence suggests that this syndrome is linked to adverse outcomes in various surgical populations. Several instruments have been developed to measure frailty, however there is no consensus about which one is the most useful in the surgical population. Therefore, this study aims to evaluate the utility of different frailty scales in the prediction of postoperative complications in older surgical population. METHODS: This review and meta-analysis assembles prospective cohort studies reporting frailty and postoperative outcomes. Searches were performed in PubMed/Medline, Scielo, Cochrane Library and ScienceDirect databases. Statistical analyses was performed using Review Manager software and the pooled Odds Rattios was calculated. RESULTS: A total of 15 articles were included in the present review. Frailty was significantly associated with postoperative complications (OR=2.53, 95% CI: 2.07-3.10; p<0.00001), mortality until 30 days (OR=3.49, 95% CI: 2.40-5.09, p<0.00001) and higher 1-year mortality (OR= 2.90, 95% CI: 1.99-4.24, p<0.00001), and with hospital length of stay >5days or >14days (OR=2.78, 95% CI: 1.45-5.30, p=0.002 and OR=2.40 (95% CI: 1.08-5.36, p= 0.03, respectively). In addition, our meta-analysis showed that frailty is a significant predictor of renal failure (OR=5.03, 95% CI: 1.74-14.54, p=0.003), neurological complications (OR= 3.41, 95% CI: 1.08-10.73, p=0.04), respiratory complications (OR=9.21 (95% CI: 2.35- 36.02, p=0.001), wound infection (OR=2.85 (95% CI: 1.65-4.94, p=0.0002) and sepsis (OR=3.84 (95% CI: 1.37-10.71, p=0.01). CONCLUSION: Overall, frailty significantly increases the risk for developing adverse outcomes after surgery, so early detection of frailty may be a window of opportunity for intervention and a key factor for improving clinical outcomes. Moreover, future studies are required for the standardization of the frailty scales used.