Associations between preoperative frailty and major postoperative complications in older surgical patients

STUDY OBJECTIVE: To assess the relationship between frailty and major postoperative complications (POCs) in elderly patients undergoing elective surgery. DESIGN: A prospective cohort study. SETTING: Five hospitals in China. PATIENTS: A total of 1358 elderly patients (≥65 years) were included. EXPOSURE: Preoperative frailty. MEASUREMENTS: The primary outcome was major POCs. LASSO regression was used for selecting covariates. Multivariate logistic regression modeling were used to evaluate the associations between frailty and major POCs. Net Reclassification Index (NRI) and Integrated Discriminant Improvement Index (IDI) were calculated to further assess the additional predictive value of the frailty for major POCs beyond the identified risk factors. Further subgroup analyses were conducted to determine the robustness of the associations. MAIN RESULTS: Logistic regression modeling revealed that frailty was associated with major POCs (adjusted odds ratio [aOR], 95 % confidence interval [CI]: 2.61, 1.47-4.62). Each 1-point increase in frailty was associated with a 35 % increase in the risk of major POCs (aOR, 95 % CI: 1.35, 1.10-1.66). Slow walking speed, low physical activity and frequent exhaustion were independently associated with major POCs. Their ORs (95 % CI): 2.34 (1.33-4.13), 1.98 (1.09-3.57), 2.26 (1.28-3.99). Adding frailty to baseline risk model improved the predictive value of major POCs (NRI: 0.5551, 0.3095-0.8006; IDI: 0.0144, 0.0003-0.0286). Subgroup analyses revealed the same trend between frailty and major POCs. CONCLUSIONS: Frail elderly patients scheduled for elective surgery were at an increased risk of major POCs, especially those with slow walking speed, low levels of physical activity, and frequent feelings of exhaustion.