Level One Trauma Center Proliferation May Worsen Patient Outcomes.

BACKGROUND: From 2013 to 2020, Arizona state trauma system expanded from seven to thirteen level 1 trauma centers (L1TCs). This study utilized the state trauma registry to analyze the effect of L1TC proliferation on patient outcomes.

METHODS: Adult patients age≥15 in the state trauma registry from 2007-2020 were queried for demographic, injury, and outcome variables. These variables were compared across the 2 time periods: 2007-2012 as pre-proliferation (PRE) and 2013-2020 as post-proliferation (POST). Multivariate logistic regression was performed to assess independent predictors of mortality. Subgroup analyses were done for Injury Severity Score (ISS)≥15, age≥65, and trauma mechanisms.

RESULTS: A total of 482,896 trauma patients were included in this study. 40% were female, 29% were geriatric patients, and 8.6% sustained penetrating trauma. The median ISS was 4. Inpatient mortality overall was 2.7%. POST consisted of more female, geriatric, and blunt trauma patients ( P < .001). Both periods had similar median ISS. POST had more interfacility transfers (14.5% vs 10.3%, P < .001). Inpatient, unadjusted mortality decreased by .5% in POST ( P < .001). After adjusting for age, gender, ISS, and trauma mechanism, being in POST was predictive of death (OR: 1.4, CI:1.3-1.5, P < .001). This was consistent across all subgroups except for geriatric subgroup, which there was no significant correlation.

DISCUSSION: Despite advances in trauma care and almost doubling of L1TCs, POST had minimal reduction of unadjusted mortality and was an independent predictor of death. Results suggest increasing number of L1TCs alone may not improve mortality. Alternative approaches should be sought with future regional trauma system design and implementation.