Impact of comorbidities in severely injured patients with blunt chest injury: a population-based retrospective cohort study

Introduction Blunt chest injuries result in up to 10% of major trauma admissions. Comorbidities can complicate recovery and increase the mortality rate in this patient cohort. A better understanding of the association between comorbidities and patient outcomes will facilitate enhanced models of care for particularly vulnerable groups of patients, such as older adults. Aims i) compare the characteristics of severely injured patients with blunt chest injury with and without comorbidities and ii) examine the relationship between comorbidities and key patient outcomes: prolonged length of stay, re-admission within 28 days, and mortality within 30 days in a cohort of patients with blunt chest injury admitted after severe trauma. Methods A retrospective cohort study using linked data from the NSW Trauma Registry and NSW mortality and hospitalisation records between 1st of January 2012 and 31st of December 2019. Results After adjusting for potential confounding factors, patients with severe injuries, chest injuries, and comorbidities were found to have a 34% increased likelihood of having a prolonged length of stay (OR=1.34, 95%I=1.17-1.53) compared to patients with no comorbidities. There was no difference in 30-day mortality for patients with a severe chest injury who did or did not have comorbidities (OR=1.05, 95%CI=0.80-1.39). No significant association was found between comorbidities and re-admission within 28 days. Conclusion Severely injured patients with blunt chest injury and comorbidities are at risk of prolonged length of stay.