Evaluation of trauma care using TRISS method: the role of adjusted misclassification rate and adjusted w-statistic.
BACKGROUND
Major trauma is a leading cause of death worldwide. Evaluation of trauma care using Trauma Injury and Injury Severity Score (TRISS) method is focused in trauma outcome (deaths and survivors). For testing TRISS method TRISS misclassification rate is used. Calculating w-statistic, as a difference between observed and TRISS expected survivors, we compare our trauma care results with the TRISS standard.


OBJECTIVE
The aim of this study is to analyze interaction between misclassification rate and w-statistic and to adjust these parameters to be closer to the truth.


METHODS
Analysis of components of TRISS misclassification rate and w-statistic and actual trauma outcome.


RESULTS
The component of false negative (FN) (by TRISS method unexpected deaths) has two parts: preventable (Pd) and non-preventable (nonPd) trauma deaths. Pd represents inappropriate trauma care of an institution; otherwise nonpreventable trauma deaths represents errors in TRISS method. Removing patients with preventable trauma deaths we get an Adjusted misclassification rate: (FP + FN - Pd)/N or (b+c-Pd)/N. Substracting nonPd from FN value in w-statistic formula we get an Adjusted w-statistic: [FP-(FN - nonPd)]/N, respectively (FP-Pd)/N, or (b-Pd)/N).


CONCLUSIONS
Because adjusted formulas clean method from inappropriate trauma care, and clean trauma care from the methods error, TRISS adjusted misclassification rate and adjusted w-statistic gives more realistic results and may be used in researches of trauma outcome.
Llullaku
Sadik S
SS
University Clinical Centre of Kosova, Department of Paediatric Surgery, 10 000 Prishtina, Kosova.
Hyseni
Nexhmi Sh
NS
University Clinical Centre of Kosova, Department of Paediatric Surgery, 10 000 Prishtina, Kosova.
Bytyçi
Cen I
CI
University Clinical Centre of Kosova, Department of Orthopaedic and Trauma Surgery, 10 000 Prishtina, Kosova.
Rexhepi
Sylejman K
SK
University Clinical Centre of Kosova, Department of Internal Diseases, 10 000 Prishtina, Kosova.