The modified frailty index and 30-day adverse events in oncologic neurosurgery

The modified frailty index (mFI) is emerging as a leading measure for preoperative risk assessment using routinely available medical record data. Our objective was to determine if mFI predicts morbidity and mortality in the diverse national cohort of patients undergoing neurosurgery for intracranial neoplasms. We identified patients in the National Surgical Quality Improvement Program who underwent oncologic neurosurgery procedures between 2008 and 2012. The mFI, ranging from 0 to 1, was calculated as the proportion of 11 possible risk factors present. We assessed the associations between mFI and 30-day mortality, neurologic and medical complications, prolonged length of stay, and unfavorable discharge in univariate and multivariable analyses and compare the index to established risk stratification techniques. A total of 9149 patients were identified. Mortality, severe medical complications, prolonged length of stay, and unfavorable discharge increased incrementally with increasing levels of frailty. Severe neurologic complications were highest in those with low frailty. In multivariable logistic regression analysis, increased frailty increased the odds of all adverse outcomes, including neurologic complications. The mFI increased the ability to predict all outcomes beyond available indices and was the most reliable predictor of neurologic complications. The mFI can be calculated from routinely collected medical record data and is predictive of 30-day adverse outcomes in a wide variety of neurosurgical oncology patients. The index may be a useful component of preoperative risk assessment with implications for shared decision-making, perioperative planning, and risk adjusted outcomes measurement in national quality registries.