Modified Frailty Index-5 Score and Post-Operative Infectious Complications in Patients Undergoing Surgery for Intestinal-Cutaneous Fistula: A Nationwide Retrospective Cohort Analysis

Background: Post-operative infectious complications after repair of intestinal-cutaneous fistulas (ICF) represent a substantial burden and these outcomes vary widely in the literature. We aimed to evaluate the use of the modified frailty index-5 (mFI-5) to account for physiologic reserve to predict infectious complications in patients with ICF undergoing operative repair. Methods: We used the American College of Surgeon National Surgical Quality Improvement Program (ACS-NSQIP) 2006-2017 dataset to include patients who underwent ICF repair. The main outcome measure was 30-day infectious complications (surgical site infection [SSI], sepsis, pneumonia, and urinary tract infection [UTI]). The risk of 30-day post-operative infectious complications was assessed based on mFI-5 score. We performed multivariable logistic regression analyses to evaluate the association between infectious complications and mFI-5. Results: We identified 4,197 patients who underwent an ICF repair. The median age (interquartile range [IQR]) was 57 (46, 67) years, and the majority of patients were female (2,260; 53.9%); white (3,348; 79.8%); and 1,586 (38.3%) were obese. After adjustment for relevant confounders such as baseline patient characteristics, and operative details, mFI-5 was independently associated with infectious complications (odds ratio [OR], 2.00; 95% confidence interval [CI], 1.25-3.21), particularly SSI (OR, 2.16; 95% CI, 1.28-3.63) and pneumonia (OR, 5.31; 95% CI, 2.29-12.35), but not UTI or sepsis. Conclusions: We showed that the mFI-5 is a strong predictor of infectious complications after ICF repair. It can be utilized to account for physiologic reserve, therefore reducing the variability of outcomes reported for ICF repair.