title: Influence of socioeconomic status on trauma center performance evaluations in a Canadian trauma system.
abstract: BACKGROUND
  Trauma center performance evaluations generally include adjustment for injury severity, age, and comorbidity. However, disparities across trauma centers may be due to other differences in source populations that are not accounted for, such as socioeconomic status (SES). We aimed to evaluate whether SES influences trauma center performance evaluations in an inclusive trauma system with universal access to health care.
  
  
  METHODS
  The study was based on data collected between 1999 and 2006 in a Canadian trauma system. Patient SES was quantified using an ecologic index of social and material deprivation. Performance evaluations were based on mortality adjusted using the Trauma Risk Adjustment Model. Agreement between performance results with and without additional adjustment for SES was evaluated with correlation coefficients.
  
  
  RESULTS
  The study sample comprised a total of 71,784 patients from 48 trauma centers, including 3,828 deaths within 30 days (4.5%) and 5,549 deaths within 6 months (7.7%). The proportion of patients in the highest quintile of social and material deprivation varied from 3% to 43% and from 11% to 90% across hospitals, respectively. The correlation between performance results with or without adjustment for SES was almost perfect (r = 0.997; 95% CI 0.995-0.998) and the same hospital outliers were identified.
  
  
  CONCLUSIONS
  We observed an important variation in SES across trauma centers but no change in risk-adjusted mortality estimates when SES was added to adjustment models. Results suggest that after adjustment for injury severity, age, comorbidity, and transfer status, disparities in SES across trauma center source populations do not influence trauma center performance evaluations in a system offering universal health coverage.
authors.affiliation: Unité de traumatologie-urgence-soins intensifs, Centre de Recherche du CHA (Hôpital de l'Enfant-Jésus), Université Laval, Quebec City, Quebec, Canada.
authors.forename: Lynne
authors.initials: L
authors.lastname: Moore
authors.forename: Alexis F
authors.initials: AF
authors.lastname: Turgeon
authors.forename: Marie-Josée
authors.initials: MJ
authors.lastname: Sirois
authors.forename: Valérie
authors.initials: V
authors.lastname: Murat
authors.forename: André
authors.initials: A
authors.lastname: Lavoie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011792:Quebec / Q000453:epidemiology; D012042:Registries; D012923:Social Class; D014193:Trauma Centers / Q000592:standards / Q000706:statistics & numerical data*; D014947:Wounds and Injuries / Q000401:mortality*