Factors associated with functional disability or mortality after elective noncardiac surgery: a prospective cohort study.

PURPOSE: Preoperative prediction of functional status after surgery is essential when practicing patient-centered medicine. We aimed to evaluate the incidence and factors associated with postoperative functional disability or all-cause mortality. Secondarily, we sought to describe the trajectory of disability in this population.

METHODS: Adults aged ≥ 55 yr who underwent elective noncardiac surgery under general anesthesia in a tertiary care hospital were followed up one year after surgery. Pre- and intraoperative factors associated with a composite outcome of postoperative functional disability or all-cause mortality were assessed using a multiple logistic regression. The sequential changes in the 12-item World Health Organization Disability Assessment Schedule (WHODAS) 2.0 score were described and stratified by surgical invasiveness.

RESULTS: Of the 2,921 patients included, 293 experienced postoperative functional disability (10.0%; 95% confidence interval [CI], 8.9 to 11.1) and 124 died (4.2%; 95% CI, 3.5 to 5.0). In a multiple regression model, the potentially modifiable risk factors, body mass index ≥ 30 kg·m-2 and poor preoperative nutritional status, were significantly associated with the primary composite outcome, as well as nonmodifiable factors such as age, preoperative comorbidities, and blood loss volume. Changes in the 12-item WHODAS 2.0 disability score varied between different levels of surgical invasiveness and types of surgery.

CONCLUSION: Within one year after surgery, one in ten patients experienced postoperative functional disability and one in 20 died. We identified potentially modifiable factors (obesity, poor nutritional status) associated with these adverse outcomes.

STUDY REGISTRATION: University Hospital Medical Information Network (UMIN000021671); registered 31 December 2015.