Comorbidities and outcomes in trauma admissions of all severities: a retrospective study

This study examines the relative prevalence of pre-existing comorbidities and their relationship with key in-hospital complications across all injury severities of a trauma patient cohort in New Zealand.

A retrospective review of data from the Te Manawa Taki (TMT) trauma registry linked to the National Minimum Dataset in New Zealand was conducted. The linked data include patients of all injury severities over 10 years, from 1 January 2014 to 31 December 2023, and pre-existing comorbidities and complications associated with admission events across facilities. Comorbidities and complications were defined using the Australia and New Zealand Trauma Registry classification.

Between 2014 and 2023, 13% of trauma admissions in the TMT Region involved patients with pre-existing comorbidities, with a mean Charlson Comorbidity Index (CCI) of 4.7 (SD=2.4). Incidence rate ratios (IRRs) show that patients of non-Māori ethnicities (1.4), females (1.8) and those aged 65 and over (4.8) are more likely (p<0.001) to have a comorbidity. Diabetes is the most common pre-existing comorbidity, followed by chronic pulmonary diseases and cerebrovascular diseases. Findings demonstrate that individuals aged 65 and over with comorbidities face a 2.2 times higher risk of in-hospital complications (p<0.001). Regression analysis indicates that having multiple comorbidities, reflected by higher CCI scores, increases the likelihood of complications in trauma patients (F[428]=0.22, p<0.001).

From a clinical and systems perspective, these findings suggest that early incorporation of comorbidity assessment in trauma pathways is essential and should be applied across the full spectrum of injury severities.