Comparing the Indices predictive of the thermal injury outcome

Abstract

Introduction. While developing the algorithms for diagnosis and treatment of patients with thermal injury, an injury outcome prediction index with the best predictive properties should be used.Aim. To compare the predictive properties of the Revised Frank Index and other specialized indices.Material and methods. A retrospective observational study included 307 patients with thermal injury, of whom 80 (26%) died. We compared the discriminatory ability, as well as sensitivity, specificity, positive predictive value and negative predictive value, the accuracy of the diagnostic test in relation to predicting a fatal outcome for 8 specialized prediction indices: RFI, FI, Baux, RBS, PBI, ABSI, BOBI, and Ryan.Results. RFI showed the largest area under the ROC curve: 0.942 [0.913–0.971], other indices had a smaller area: FI 0.827 [0.768–0.886], Baux 0.860 [0.811–0.909], RBS  0.891 [0.848–0.933], PBI 0.893 [0.848–0.937], ABSI 0.838 [0.786–0.890], BOBI 0.865 [0.819–0.910], Ryan 0.816 [0.764–0.869]. The Ryan index had the highest sensitivity (95%), but its specificity (49%) was the lowest, and the proportion of false positive results was 60%. The RBS index had high sensitivity (84%) and specificity (80%), but the false positive rate was 40%. The RFI and PBI indices showed similar sensitivity (81%), however, the proportion of false positive results for RFI (23%) was lower than that of PBI (39%) and all other indices, and the RFI accuracy in predicting the outcome was the highest among the other indices, making 89%.Conclusion. The predictive properties of the Revised Frank Index are better than those of other specialized indices.