Objective Estimates of the Probability of Death from Burn Injuries

Abstract

BACKGROUND: Over the past 20 years, there has been remarkable improvement in the chances of survival of patients treated in burn centers. A simple, accurate system for objectively estimating the probability of death would be useful in counseling patients and making medical decisions. METHODS: We conducted a retrospective review of all 1665 patients with acute burn injuries admitted from 1990 to 1994 to Massachusetts General Hospital and the Shriners Burns Institute in Boston. Using logistic-regression analysis, we developed probability estimates for the prediction of mortality based on a minimal set of well-defined variables. The resulting mortality formula was used to determine whether changes in mortality have occurred since 1984, and it was tested prospectively on all 530 patients with acute burn injuries admitted in 1995 or 1996. RESULTS: Of the 1665 patients (mean [+/-SD] age, 21+/-20 years; mean burn size, 14+/-20 percent of body-surface area), 1598 (96 percent) lived to discharge. The mean length of stay was 21+/-29 days. Three risk factors for death were identified: age greater than 60 years, more than 40 percent of body-surface area burned, and inhalation injury. The mortality formula we developed predicts 0.3 percent, 3 percent, 33 percent, or approximately 90 percent mortality, depending on whether zero, one, two, or three risk factors are present. The results of the prospective test of the formula were similar. A large increase in the proportion of patients who chose not to be resuscitated complicated comparisons of mortality over time. CONCLUSIONS: The probability of mortality after burns is low and can be predicted soon after injury on the basis of simple, objective clinical criteria.