Context The premise underlying regionalization of trauma care is that larger
volumes of trauma patients cared for in fewer institutions will lead to improved
outcomes. However, whether a relationship exists between institutional volume
and trauma outcomes remains unknown.
Objective To evaluate the association between trauma center volume and outcomes
of trauma patients.
Design Retrospective cohort study.
Setting Thirty-one academic level I or level II trauma centers across the United
States participating in the University Healthsystem Consortium Trauma Benchmarking
Patients Consecutive patients with penetrating abdominal injury (PAI; n = 478)
discharged between November 1, 1997, and July 31, 1998, or with multisystem
blunt trauma (minimum of head injury and lower-extremity long-bone fractures;
n = 541) discharged between June 1 and December 31, 1998.
Main Outcome Measures Inpatient mortality and hospital length of stay (LOS), comparing high-volume
(>650 trauma admissions/y) and low-volume (≤650 admissions/y) centers.
Results After multivariate adjustment for patient characteristics and injury
severity, the relative odds of death was 0.02 (95% confidence interval [CI],
0.002-0.25) for patients with PAI admitted with shock to high-volume centers
compared with low-volume centers. No benefit was evident in patients without
shock (P = .50). The adjusted odds of death in patients
with multisystem blunt trauma who presented with coma to a high-volume center
was 0.49 (95% CI, 0.26-0.93) vs low-volume centers. No benefit was observed
in patients without coma (P = .05). Additionally,
a shorter LOS was observed in patients with PAI and New Injury Severity Scores
of 16 or higher (difference in adjusted mean LOS, 1.6 days [95% CI, −1.5
to 4.7 days]) and in all patients with multisystem blunt trauma admitted to
higher-volume centers (difference in adjusted mean LOS, 3.3 days [95% CI,
Conclusions Our results indicate that a strong association exists between trauma
center volume and outcomes, with significant improvements in mortality and
LOS when volume exceeds 650 cases per year. These benefits are only evident
in patients at high risk for adverse outcomes.