Measurement and validation of frailty as a predictor of outcomes in women undergoing major gynaecological surgery

Objective Frailty is the loss of physical or mental reserve that impairs function, often in the absence of a defined comorbidity. Our aim was to determine whether a modified frailty index (mFI) correlates with morbidity and mortality in patients undergoing hysterectomy. Design Retrospective cohort study. Setting Hospitals across the USA participating in the National Surgical Quality Improvement Program (NSQIP). Sample Patients who underwent hysterectomy from 2008 to 2012. Methods An mFI was calculated using 11 variables in NSQIP. The associations between mFI and morbidity and mortality were assessed. Model fit statistics (c-statistics) were utilised to evaluate the ability of mFI to distinguish outcomes. Main outcome measure Wound infection, severe complications and mortality. Results A total of 66 105 patients were identified. Wound complications increased from 2.4% in patients with an mFI of zero to 4.8% in those with mFI ≥ 0.5 (P < 0.0001). Similarly, severe complications increased from 0.98% to 7.3% (P < 0.0001), overall complications rose from 3.7% to 14.5% (P < 0.0001) and mortality increased from 0.06% to 3.2% (P < 0.0001) for patients with a frailty index of zero compared with those with an index of ≥0.5. Versus chance, the goodness-of-fit c-statistics suggested that mFI increases the ability to detect wound complications by 11.4%, severe complications by 22.0% and overall complications by 11.0%. Conclusions The mFI is easily reproducible from routinely collected clinical data and predictive of outcomes in patients undergoing hysterectomy. Frailty may be useful in the preoperative risk assessment of women undergoing gynaecological surgery.