Association of the prealbumin–albumin nutritional index with short-term mortality in hospitalized patients with traumatic brain injury

Methods This single-center retrospective cohort study included 2,221 patients with TBI admitted between March 29, 2018, and September 23, 2024. PANI was calculated as serum prealbumin (mg/L) multiplied by albumin (g/L) and was divided by 1,000 for analysis. The first available laboratory measurements after admission were used. The primary and secondary outcomes were all-cause in-hospital mortality and 7-day in-hospital mortality, respectively. Associations were assessed using Cox proportional hazards models. Discrimination was evaluated using receiver operating characteristic curves and pairwise comparisons of areas under the curve (AUCs). Results Among 2,221 patients, 78 (3.5%) died during hospitalization and 47 (2.1%) died in hospital within 7 days of admission. In the primary adjusted model (Model 3), each 1-unit increase in PANI/1,000 was associated with lower hazards of in-hospital mortality (HR, 0.613; 95% CI, 0.560–0.671) and 7-day in-hospital mortality (HR, 0.640; 95% CI, 0.574–0.714). Corresponding HRs in the supplementary extended baseline model (Model 4) were 0.653 (95% CI, 0.593–0.720) and 0.690 (95% CI, 0.616–0.773), respectively. In the complete-case sensitivity analysis additionally incorporating body mass index and systolic blood pressure, the corresponding HRs were 0.562 (95% CI, 0.466–0.678) and 0.677 (95% CI, 0.528–0.870). PANI alone yielded AUCs of 0.856 (95% CI, 0.810–0.902) and 0.837 (95% CI, 0.774–0.901), respectively. Conclusion Lower PANI was associated with higher in-hospital and 7-day in-hospital mortality in patients with TBI. However, the single-center design, potential selection bias, residual confounding, and absence of key neurological and imaging severity variables preclude conclusions regarding its clinical utility. The potential clinical value of PANI can only be evaluated after validation in multicenter prospective studies incorporating complete neurological and imaging assessments.