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Mortality Benefit of Transfer to Level I versus Level II Trauma Centers for Head‐Injured Patients
Author(s) -
McConnell K. John,
Newgard Craig D.,
Mullins Richard J.,
Arthur Melanie,
Hedges Jerris R.
Publication year - 2005
Publication title -
health services research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.706
H-Index - 121
eISSN - 1475-6773
pISSN - 0017-9124
DOI - 10.1111/j.1475-6773.2005.0u367.x
Subject(s) - trauma center , medicine , injury severity score , confidence interval , abbreviated injury scale , poison control , injury prevention , head trauma , head injury , retrospective cohort study , emergency medicine , emergency department , surgery , psychiatry
Objective. To determine whether head‐injured patients transferred to level I trauma centers have reduced mortality relative to transfers to level II trauma centers. Data Source/Study Setting. Retrospective cohort study of 542 patients with head injury who initially presented to 1 of 31 rural trauma centers in Oregon and Washington, and were transferred from the emergency department to 1 of 15 level I or level II trauma centers, between 1991 and 1994. Study Design. A bivariate probit, instrumental variables model was used to estimate the effect of transfer to level I versus level II trauma centers on 30‐day postdischarge mortality. Independent variables included age, gender, Injury Severity Scale (ISS), other indicators of injury severity, and a dichotomous variable indicating transfer to a level I trauma center. The differential distance between the nearest level I and level II trauma centers was used as an instrument. Principal Findings. Patients transferred to level I trauma centers differ in unmeasured ways from patients transferred to level II trauma centers, biasing estimates based on standard statistical methods. Transfer to a level I trauma center reduced absolute mortality risk by 10.1% (95% confidence interval 0.3%, 22.2%) compared with transfer to level II trauma centers. Conclusions. Patients with severe head injuries transferred from rural trauma centers to level I centers are likely to have improved survival relative to transfer to level II centers.