Journal of Emergencies, Trauma, and Shock

ORIGINAL ARTICLE
Year
: 2012  |  Volume : 5  |  Issue : 4  |  Page : 333--337

Comparing regression-adjusted mortality to standardized mortality ratios for trauma center profiling


Lynne Moore1, James A Hanley1, Alexis F Turgeon2, André Lavoie3 
1 Department of Epidemiology and Biostatistics. McGill University, Montreal, Canada
2 Unité de traumatologie-urgence-soins intensifs, Centre de Recherche du CHA (Hôpital de l'Enfant-Jésus), Université Laval; Département d'anesthésiologie, Division de soins intensifs, Hôpital de l'Enfant-Jésus, Université Laval, Quebec City, Quebec, Canada
3 Unité de traumatologie-urgence-soins intensifs, Centre de Recherche du CHA (Hôpital de l'Enfant-Jésus), Université Laval, Canada

Correspondence Address:
Lynne Moore
Department of Epidemiology and Biostatistics. McGill University, Montreal
Canada

Background: Trauma center profiling is commonly performed with Standardized Mortality Ratios (SMRs). However, comparison of SMRs across trauma centers with different case mix can induce confounding leading to biased trauma center ranks. We hypothesized that Regression-Adjusted Mortality (RAM) estimates would provide a more valid measure of trauma center performance than SMRs. Objective: Compare trauma center ranks generated by RAM estimates to those generated by SMRs. Materials and Methods: The study was based on data from a provincial Trauma Registry (1999-2006; n = 88,235). SMRs were derived as the ratio of observed to expected deaths using: (1) the study population as an internal standard, (2) the US National Trauma Data Bank as an external standard. The expected death count was calculated as the sum of mortality probabilities for all patients treated in a hospital conditional on the injury severity score, the revised trauma score, and age. RAM estimates were obtained directly from a hierarchical logistic regression model. Results: Crude mortality was 5.4% and varied between 1.3% and 13.5% across the 59 trauma centers. When trauma center ranks from internal SMRs and RAM were compared, 49 out of 59 centers changed rank and six centers changed by more than five ranks. When trauma center ranks from external SMRs and RAM were compared, 55 centers changed rank and 17 changed by more than five ranks. Conclusions: The results of this study suggest that the use of SMRs to rank trauma centers in terms of mortality may be misleading. RAM estimates represent a potentially more valid method of trauma center profiling.


How to cite this article:
Moore L, Hanley JA, Turgeon AF, Lavoie A. Comparing regression-adjusted mortality to standardized mortality ratios for trauma center profiling.J Emerg Trauma Shock 2012;5:333-337


How to cite this URL:
Moore L, Hanley JA, Turgeon AF, Lavoie A. Comparing regression-adjusted mortality to standardized mortality ratios for trauma center profiling. J Emerg Trauma Shock [serial online] 2012 [cited 2020 Apr 6 ];5:333-337
Available from: http://www.onlinejets.org/article.asp?issn=0974-2700;year=2012;volume=5;issue=4;spage=333;epage=337;aulast=Moore;type=0