A Comparison of Abbreviated Burns Severity Index and the Revised Baux Score in Predicting Severity and Mortality in Moderate to Severe Burns in Kenyatta National Hospital

Abstract

Background: Scoring systems in burns’ injury aid in determining severity of injury, type of management and the prediction of outcome. They facilitate accurate decision-making and provide guidance to the patients’ families. Ideally, these tools should be simple, reliable, objective, and applicable in clinical setting. The routine use of trauma scores do not perform well when applied to burns injuries .This thus spells out the need to find an accurate and reproducible scoring system in our setup. Objective: To establish the accuracies of the Revised Baux score and the Abbreviated Burn Severity Index in predicting outcome in patients with moderate to severe burns, and subsequently compare the two tests. Methodology: This was a prospective cohort study done over a period of 6 months at the Kenyatta National Hospital, which is a tertiary center of burn care management. On each of the patients, data was collected on demographics, total body surface area (TBSA) burnt, presence of inhalational injury and full thickness injury. The Revised Baux score (RBS and Abbreviated Burn Severity Index (ABSI) were administered to each patient concurrently and either mortality or survivability respectively, were observed and documented after 30 days. Analysis was done using SPSS version 23. Descriptive data was summarized in means (STD deviations), modes, frequencies, and percentages. Sensitivity, specificity, positive predictive and negative predictive values were determined. Area under the curve was also calculated for the two scores. Binomial test was used to compare z-values for the AUC for the two scores. P value of 0.05 was considered statistically significant at 95% confidence interval. Results: A total of 163 patients were recruited. Average age was 16 years ±18.05 with an M: F ratio of 1.2:1. The overall mortality rate was 20.9%. The weighted accuracies of the ABSI and the RBS was 92.4%% and 79.5%% respectively. The ABSI had a higher sensitivity 94.3% and PPV 97.3% than that of the RBS. The two tests showed good AUROC values of 0.90 and 0.87 for the ABSI and the RBS respectively for the prediction of outcome in burns patients. The two AUROCs were then compared based on binomial ROC curve estimation, and there was no statistical significance difference (p =0.395) between the two tests. Conclusion: Both the ABSI and the RBS were noted to be simple to calculate and accurate in predicting outcome and documenting burn injury severity in our set-up. Albeit the ABSI had a slightly higher area under the curve than the RBS, there was no statistically significant difference between the two tests. This concludes that both ABSI and the RBS would perform equally in predicting outcome in moderate to severe burns in our setup.