Effect of prehospital cervical spine immobilization on mortality and neurological outcome in trauma patients: an observational cohort study with propensity score matching based on the trauma registry of the German trauma society (TraumaRegister DGU®).

BACKGROUND: Prehospital cervical spine immobilization is standard trauma care intended to prevent secondary spinal cord injury, yet evidence for its effectiveness is limited, and adverse effects are increasingly recognized. Large registry-based comparisons accounting for injury severity are scarce. This study investigated the association between prehospital cervical spine immobilization and hospital mortality and neurological outcome in trauma patients. METHODS: Retrospective, multicenter, observational cohort analysis of the TraumaRegister DGU® (2020-2022). Patients aged ≥ 1 year who were primarily admitted in Germany, Austria, or Switzerland and had documented cervical spine immobilization, pupil status, and prehospital Glasgow Coma Scale (GCS) were included. A propensity score from logistic regression on injury severity, mechanism, and prehospital parameters was used for exact 1:1 matching, repeated in the subgroup with cervical spine injury (AIS ≥ 2). PRIMARY OUTCOME: hospital mortality; secondary outcome: Glasgow Outcome Scale (GOS) at discharge from the acute trauma admission. RESULTS: Out of 31,055 patients, the prevalence of cervical spine injury (AIS ≥ 3) was 3.5%, only 65.9% received cervical spine immobilization. Immobilized patients had higher injury severity and were more likely to have high-energy trauma or be treated by an emergency physician. In the matched cohort (n = 16,922), no clinically meaningful difference was observed in hospital mortality (12.0% with immobilization vs. 13.6% without; p = 0.001) or in crude neurological outcome at discharge as measured by the Glasgow Outcome Scale (GOS). In the subgroup with confirmed cervical spine injury (AIS ≥2; n = 1,362), mortality (17.9% non-immobilized vs. 18.2% immobilized, p = 0.888) and neurological recovery did not differ significantly between groups (vegetative state: 1.8% non-immobilized vs. 2.7% immobilized, good recovery 46.2% non-immobilized vs. 43.4% immobilized, p = 0.626). GCS change between scene and hospital arrival - a confounded, non-specific measure-showed marginally more improvement in immobilized patients (15.7% vs. 12.8%; p < 0.001). CONCLUSIONS: In this registry-based analysis, prehospital cervical spine immobilization-recorded as a binary variable-was not associated with a measurable difference in hospital mortality or in crude neurological outcome at discharge (GOS), even in patients with confirmed cervical spine injury. These findings do not support routine, undifferentiated immobilization.