Expert consensus vs empirical estimation of injury severity: effect on quality measurement in trauma.
ABSTRACT To determine the extent to which the Injury Severity Score (ISS) and Trauma Mortality Probability Model (T-MPM), a new trauma injury score based on empirical injury severity estimates, agree on hospital quality.
Retrospective cohort study based on 66,214 patients in 68 hospitals. Four risk-adjustment models based on either ISS or T-MPM were constructed, with or without physiologic information.
Hospital quality was measured using the ratio of the observed-to-expected mortality rates. Pairwise comparisons of hospital quality based on ISSaugmented vs T-MPMaugmented were performed using the intraclass correlation coefficient and the kappa statistic.
There was almost perfect agreement for the ratios of the observed to expected mortality rates based on the T-MPM vs the ISS when physiologic information was included in the model (intraclass correlation coefficient, 0.93). There was substantial agreement on which hospitals were identified as high-, intermediate-, and low-quality hospitals (kappa = 0.79). Excluding physiologic information decreased the level of agreement between the T-MPM and the ISS (intraclass correlation coefficient, 0.88 and kappa = 0.58).
The choice of expert-based or empirical Abbreviated Injury Score severity scores for individual injuries does not seem to have a significant effect on hospital quality measurement when physiologic information is included in the prediction model. This finding should help to convince all stakeholders that the quality of trauma care can be accurately measured and has face validity.
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ABSTRACT: This report describes a project funded by the Agency for Healthcare Research and Quality to evaluate the impact of providing hospitals with nonpublic report cards on trauma outcomes. The Survival Measurement and Reporting Trial for Trauma explores the feasibility of using the National Trauma Data Bank as a platform for measuring and improving trauma outcomes. We identified a cohort of 125 hospitals in the National Trauma Data Bank with annual hospital volumes of 250 or more trauma cases meeting specific minimum criteria for data quality. The performance of hospitals in this cohort was evaluated using hierarchical logistic regression model. The effect of each hospital on trauma mortality was captured by a shrinkage coefficient, which is exponentiated to yield an adjusted odds ratio. This adjusted odds ratio represents the likelihood that a trauma patient treated at a specific hospital is more or less likely to die compared with a patient treated at an "average" hospital. The initial hospital cohort includes 125 hospitals and 157,045 patients admitted in 2006. Most hospitals are either level I (36%) or level II (34%) trauma centers. Patients admitted to the worst-performing hospitals were at least 50% more likely to die than patients admitted to the average hospital, after adjusting for injury severity. The initial findings of this trial suggest that there is significant variability in trauma mortality across centers caring for injured patients after adjusting for differences in patient casemix. This variation in risk-adjusted mortality presents an opportunity for improvement. The Survival Measurement and Reporting Trial for Trauma study is designed to test the hypothesis that nonpublic report cards can lead to improved population mortality for injured patients. The results of this study may have substantial implications in the future design and implementation of a national effort to report and improve trauma outcomes in the United States.The Journal of trauma 06/2010; 68(6):1491-7. DOI:10.1097/TA.0b013e3181bb9a55 · 2.96 Impact Factor
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ABSTRACT: This paper discusses mathematical models of expressing severity of injury and probability of survival following trauma and their use in establishing clinical governance of a trauma system. There are five sections: (i) Historical overview of scoring systems--anatomical, physiological and combined systems and the advantages and disadvantages of each. (ii) Definitions used in official statistics--definitions of 'killed in action' and other categories and the importance of casualty reporting rates and comparison across conflicts and nationalities. (iii) Current scoring systems and clinical governance--clinical governance of the trauma system in the Defence Medical Services (DMS) by using trauma scoring models to analyse injury and clinical patterns. (iv) Unexpected outcomes--unexpected outcomes focus clinical governance tools. Unexpected survivors signify good practice to be promulgated. Unexpected deaths pick up areas of weakness to be addressed. Seventy-five clinically validated unexpected survivors were identified over 2 years during contemporary combat operations. (v) Future developments--can the trauma scoring methods be improved? Trauma scoring systems use linear approaches and have significant weaknesses. Trauma and its treatment is a complex system. Nonlinear methods need to be investigated to determine whether these will produce a better approach to the analysis of the survival from major trauma.Philosophical Transactions of The Royal Society B Biological Sciences 01/2011; 366(1562):171-91. DOI:10.1098/rstb.2010.0232 · 6.31 Impact Factor
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ABSTRACT: The Injury Severity Score (ISS) is the most commonly used measure of injury severity. The score has been shown to have excellent predictive capability for trauma mortality and has been validated in multiple data sets. However, the score has never been tested to see if its discriminatory ability is affected by differences in race and gender. This study is aimed at validating the ISS in men and women and in three different race/ethnic groups using a nationwide database. Retrospective analysis of patients age 18-64 y in the National Trauma Data Bank 7.0 with blunt trauma was performed. ISS was categorized as mild (<9,) moderate (9-15), severe (16-25), and profound (>25). Logistic regression was done to measure the relative odds of mortality associated with a change in ISS categories. The discriminatory ability was compared using the receiver operating characteristics curves (ROC). A P value testing the equality of the ROC curves was calculated. Age stratified analyses were also conducted. A total of 872,102 patients had complete data for the analysis on ethnicity, while 763,549 patients were included in the gender analysis. The overall mortality rate was 3.7%. ROC in Whites was 0.8617, in Blacks 0.8586, and in Hispanics 0.8869. Hispanics have a statistically significant higher ROC (P value < 0.001). Similar results were observed within each age category. ROC curves were also significantly higher in females than in males. The ISS possesses excellent discriminatory ability in all populations as indicated by the high ROCs.Journal of Surgical Research 03/2011; 166(1):40-4. DOI:10.1016/j.jss.2010.04.012 · 2.12 Impact Factor