The effect of trauma center care on pediatric injury mortality in California, 1999 to 2011

Abstract

Background: Trauma centers (TCs) have been shown to decrease mortality in adults, but this has not been demonstrated at a population level in all children. We hypothesized that seriously injured children would have increased survival in a TC versus nontrauma center (nTC), but there would be no increased benefit from pediatric-designated versus adult TC care.

Methods: This was a retrospective study of the unmasked California Office of Statewide Health and Planning Department patient discharge database (1999-2011). DRG International Classification of Diseases-9th Rev. (ICD-9) diagnostic codes indicating trauma were identified for children (0-18 years), and injury severity was calculated from ICD-9 codes using validated algorithms. To adjust for hospital case mix, we selected patients with ICD-9 codes that were capable of causing death and which appeared at both TCs and nTCs. Instrumental variable (IV) analysis using differential distance between the child's residence to a TC and to the nearest hospital was applied to further adjust for unobservable differences in TC and nTC populations. Instrumental variable regression models analyzed the association between mortality and TC versus nTC care as well as for pediatric versus adult TC designations, adjusting for demographic and clinical variables.

Results: Unadjusted mortality for the entire population of children with nontrivial trauma (n = 445,236) was 1.2%. In the final study population (n = 77,874), mortality was 5.3%, 3.8% in nTCs and 6.1% in TCs. IV regression analysis demonstrated a 0.79 percentage point (95% confidence interval, -0.80 to -0.30; p = 0.044) decrease in mortality for children cared for in TC versus nTC. No decrease in mortality was demonstrated for children cared for in pediatric versus adult TCs.

Conclusion: Our IV TC outcome models use improved injury severity and case mix adjustment to demonstrate decreased mortality for seriously injured California children treated in TCs. These results can be used to take evidence-based steps to decrease disparities in pediatric access to, and subsequent outcomes for, trauma care.

Level of evidence: Therapeutic/care management, level III.

Figure 1. Derivation of patient study sample from the California Office of Statewide Health Planning and Development Patient Discharge Database (1999–2011)

*=Excludes children with sole codes indicating minor injuries, perinatal or pregnancy associated conditions, burn injuries. **=Children cared for in level III and IV TCs were eliminated when matching TC and ntC diagnoses ***=Categories are not mutually exclusive