Chart-Derived Frailty Index and 90-Day Mortality After Burn Surgery

Frailty is a reduced physiological reserve condition associated with postoperative morbidity and mortality. The chart-derived frailty index (CFI) can measure frailty using demographic and laboratory values. We evaluated the association of preoperative CFI with 90-d mortality after burn surgery.

This large retrospective study included burn intensive care unit (ICU) patients between 2012 and 2021 and calculated CFI using the sum of the following five variables: age >70 y, body mass index <18.5 kg/m², hematocrit <35%, albumin <3.4 g/dL, and creatinine >2.0 mg/dL; high CFI was a score of 3-5. Postoperative 90-d mortality rate, major adverse cardiac events (MACE), pneumonia, continuous renal replacement therapy (CRRT) requirement, and prolonged ICU stay (>60 d) were evaluated.

Of 1118 patients, 147 (13.1%) had high CFI. High CFI patients had a higher 90-d mortality rate than did low CFI patients (38.8% versus 22.6%, P < 0.001). A high CFI was significantly associated with postoperative 90-d mortality (hazard ratio = 4.124, 95% confidence interval = 2.980-5.707, P < 0.001) in multivariate Cox regression analysis. Kaplan-Meier analysis revealed significantly different postoperative 90-d mortality rates between patients with high and low CFIs (log-rank test, P < 0.001). Incidences of postoperative MACE, pneumonia, the need for CRRT, and prolonged ICU stay were significantly higher in patients with high CFIs than in those with low CFIs.

Preoperative high CFI was associated with increased 90-d mortality, MACE, pneumonia, CRRT requirement, and ICU stay following burn surgery.