Association of total body surface area on effective surgical treatment and mortality in adult burn patients: A 5-year retrospective analysis in an Indonesian National Referral Hospital

Abstract: OBJECTIVES: This study evaluates the association of total body surface area (TBSA) on surgical treatment outcomes and mortality rates in burn patients. METHODS: A retrospective cohort study was conducted on adult burn patients admitted to an Indonesian National Referral Hospital from January 2020 to November 2024. Factors associated with mortality, including age, TBSA, and surgery count, were analyzed using the SPSS software version 26. RESULTS: This study included 595 patients, with a mean age of 41.74 ± 14.95 years and a male predominance ( n = 406, 68.2%). Flame or explosion-related burns were the most common cause of hospitalization ( n = 473, 79.4%). Overall mortality was 42.2%. Surgical activity and length of stay (LOS) increased with TBSA, peaking in the 21%–40% groups (median operations 3 [interquartile range 2–4]), but declined in >40% TBSA due to early deaths. Kaplan–Meier curves confirmed steep survival loss within 2 weeks among >40% TBSA patients (log-rank P < 0.001). In multivariable regression, independent predictors of mortality were age (adjusted odds ratio [aOR] 1.021, P = 0.004), male sex (aOR 1.60, P = 0.040), TBSA 31%–40% (aOR 8.27, P = 0.002), and > 40% (aOR 22.3, P < 0.001). Longer LOS (aOR 0.967, P = 0.019) and more operations (aOR 0.737, P < 0.001) were protective. Receiver operating characteristic analysis of numeric TBSA showed good discrimination (AUC = 0.813), with an optimal cutoff at ~ 33.8% (sensitivity 83.7%, specificity 66.3%). CONCLUSION: TBSA remains the principal driver of burn outcomes, with mortality risk rising sharply beyond ~34%. Early deaths in the largest burn group explain the paradox of fewer operations despite extensive injury.