The volume-outcome relationship in severely injured patients remains under debate and this has consequences for the designation of trauma centers.
The aim of this study was to evaluate the relationship between hospital or surgeon volume and health outcomes in severely injured patients.
Six electronic databases were searched from 1980 up to January 30, 2018, to identify studies that describe the relationship between hospital or surgeon volume and health outcomes in severely injured patients (preferably Injury Severity Score above 15). Selection of relevant studies, data extraction, and critical appraisal of the methodological quality were performed by two independent reviewers. Pooled adjusted and unadjusted estimates of the effect of volume on in-hospital mortality, only in study populations with Injury Severity Score greater than 15, were calculated with a random-effects meta-analysis. A mixed effects linear regression model was used to assess hospital volume as continuous parameter.
Eighteen observational cohort studies were included. The majority (13 [72%] of 18) reported an association between higher hospital or surgeon volume and lower mortality rate. Overall, the quality of the included studies was reasonable, with insufficient adjustment as one of the most common limitations. Eight studies were included in the meta-analysis with a total of 222,418 patients. High hospital volume (>240 admitted severely injured patients per year) was associated with a lower risk of mortality (adjusted odds ratio, 0.85; 95% confidence interval, 0.76–0.94). Four studies were included in the regression model, providing a beta of −0.17 per 10 patients (95% CI, −0.27 to −0.07). There was no clear association between surgeon volume and mortality rates based on three available studies.
Our systematic overview of the literature reveals a modest association between high-volume centers and lower mortality in severely injured patients, suggesting that designation of high-volume centers might improve outcomes among severely injured patients.
Systematic review and meta-analysis, level III. Systematic review registration number: PROSPERO registration ID CRD42017056729
From the Department of Public Health (C.A.S., E.J.A.W., E.V., H.F.L.), Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Neurology (E.V.), Erasmus University Medical Center, Rotterdam, The Netherlands.; School of Health and Related Research (F.E.L.), Sheffield University, Salford Royal NHS Foundation Trust, Salford, United Kingdom; Trauma Audit and Research Network (F.E.L.), University of Manchester, Salford, Manchester, United Kingdom; Department of Emergency Medicine (S.C.E.S.), Erasmus University Medical Center, Rotterdam, The Netherlands; and Trauma Research Unit, Department of Surgery (D.D.H.), Erasmus MC University Medical Center, Rotterdam, The Netherlands.
Submitted: March 28, 2018, Revised: April 25, 2018, Accepted: July 11, 2018, Published online: August 7, 2018.
Address for reprints: Charlie Aletta Sewalt, Department of Public Health, Erasmus University Medical Center, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands; email: firstname.lastname@example.org.
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