Predictors of prolonged length of stay and mortality in burn Patients: A tertiary burn center experience

• Low BMI burn patients had eight times the risk of a long hospital stays. • Acid chemical burns quadrupled the risk of a long hospital stay. • Unstable vital signs at admission tripled the risk of a long hospital stay. • Full-thickness burns had eight times the risk of in-hospital mortality. Burn injuries are among the most complex forms of trauma, often requiring prolonged hospitalization and carrying significant mortality risk. Understanding the factors that influence length of stay (LOS) and outcomes is essential for improving care and optimizing resource use. We reviewed all adult burn patients admitted to King Abdulaziz Medical City, Riyadh, between January 2019 and December 2024. Clinical and demographic data were collected, and outcomes were analyzed retrospectively. Predictors of prolonged LOS (≥30 days) and in-hospital mortality were identified using multivariate logistic regression after initial univariate testing. The study included 305 patients, predominantly male (78.4%), with a mean age of 38.5 years. Flame burns were the leading cause (56.7%), and three-quarters of patients underwent surgical intervention. Mortality occurred in 7.5% of cases. Independent predictors of prolonged LOS were underweight BMI (<18.5) (OR 7.8, 95% CI 2.3–26.5), acid chemical burns (OR 4.0, 95% CI 1.1–14.7), and physiological instability at presentation (OR 3.4, 95% CI 1.5–7.4). Mortality was significantly associated with older age (OR 1.1, 95% CI 1.0–1.1) and full-thickness burns (OR 8.0, 95% CI 1.3–47.9). Inhalation injury and lower limb involvement showed non-significant trends toward higher risk, while overweight BMI appeared protective. Low BMI, chemical burn etiology, and physiological instability predicted longer hospitalization, whereas age and full-thickness burns were the strongest mortality factors. Recognizing these risks at admission can guide early, individualized management and support more efficient use of burn unit resources.