Age-dependent influence of premorbid underweight status on mortality in severe burn patients: An administrative database study

Abstract

PurposeTo examine the associations between premorbid nutritional status and in-hospital mortality in severe burn patients according to age in Japan. MethodsWe retrospectively extracted the data of 14,345 patients aged 18–84 years admitted for burns from April 1, 2014, to March 31, 2018, using the Japanese Diagnosis Procedure Combination database. The exclusion criteria were out-of-hospital cardiac arrest, death in the emergency room, readmission, and planned admission. We collected data on age, sex, height, weight, comorbidities, burn index, and mechanical ventilation use and performed age-stratified multilevel logistic regression analyses to estimate associations between premorbid body mass index (BMI) and in-hospital mortality. ResultsWe analyzed 2968 patients with a burn index ≥10, including 831 elderly aged 75–84 years. In patients aged 18–74 years, being underweight (BMI < 18.5) significantly decreased mortality (0.34 [0.15–0.77]; P = 0.010). In contrast, in patients aged 75–84 years, being underweight significantly increased mortality (2.11 [1.05–4.25]; P = 0.036). Being overweight (BMI >25) increased mortality in both age groups, but not significantly. ConclusionsThe results suggest that pre-morbidly underweight elderly patients aged 75–84 years with severe burns have high mortality risks. Further research is needed to identify optimal care strategies for this population.