Evaluating the association of the new National Surgical Quality Improvement Program modified 5-factor frailty index with outcomes in elective colorectal surgery.

Abstract

The 5-factor modified frailty index (mFI-5) is a new, NSQIP-based, predictive tool for mortality and postoperative complications. The mFI-5's predictive ability has been validated within the large-scale NSQIP database but applicability in institutional databases has not been investigated. We sought to assess the association between the mFI-5 and morbidity/mortality at the institutional level. A divisional database was queried for 2017 elective colorectal resections and an mFI-5 calculated. The main outcome measure was the association and predictive value of the mFI-5 with major morbidity/mortality and minor complications. Univariable analyses were performed via the Cochran-Armitage Test and Cramer's V. Logistic regression evaluated the relationship between the mFI-5 and morbidity/mortality while accounting for demographics and pre-operative risk factors. Receiver operating characteristic (ROC) curves were plotted to visualize the predictive strength for outcomes. Four hundred and twelve patients were analyzed. 8.7% had major morbidity/mortality and 31.6% minor complications. The mFI-5 categorized patients into 0 (n = 335), 1 (n = 58), and 2+ (n = 19) groups. Univariable analysis showed a higher mFI-5 was associated significantly with major morbidity/mortality (P = 0.004), but not minor (P = 0.281). Multivariable logistic regression showed a strong association between an mFI-5 score of 2+ with major complications (Major: OR = 4.616, CI [1.442-14.776], P = 0.010). ROC curves showed the mFI-5 was poor for predicting outcomes and performed better when other risk factors were added to the model. The mFI-5 tool has an independent association with major morbidity/mortality in an institutional dataset for elective colorectal surgery, but is not predictive. Its predictive ability is enhanced when other patient-specific risk factors are incorporated.