Incidence and outcomes of major trauma patients with thoracic injuries and rib fractures in Aotearoa New Zealand

Introduction: Thoracic trauma represents a significant burden of disease in Aotearoa, New Zealand (AoNZ). To date, no study has examined the incidence or outcomes of patients suffering major thoracic trauma, or major trauma and rib fractures in AoNZ. Methods: A 6 year retrospective study of all major trauma (Injury Severity Score >12) patients in AoNZ was performed. The National Trauma Registry was searched to identify patients. The National Minimum Data Set was searched for all ICD-10 codes associated with surgical stabilisation of rib fractures (SSRF). Poisson regression was used to determine the change in incidence rate over the study period adjusted for age with the logarithm of population size as the offset variable. The incidence rate ratios (IRR) with 95% confidence intervals (CI) were reported. Results: 12,218 patients sustained major trauma. 7,059 (57.8%) of these patients sustained thoracic injuries. Of these patients, 5,585 (79.1%) sustained rib fractures, and 180 (3.2%) proceeded to SSRF. A flail segment was observed in 16% of patients with rib fractures. Transport was the mechanism of injury in 53% of patients. During the study the incidence (cases per 100,000 people per year) of major trauma increased from 39.5 to 49.3 (IRR 1.05, 95%CI 1.04 to 1.07, <0.001), the incidence of thoracic injuries from 21.3 to 28.7 (1.07, 95% CI 1.05 to 1.08, <0.001) and the incidence of rib fractures from 16.0 to 22.9 (1.08, 95% CI 1.06 to 1.09, <0.001). SSRF was performed in 3.2% of patients with rib fractures and increased from 0.2 to 0.8 cases per 100,000 people per year (1.27, 95% CI 1.15 to 1.41, <0.001) during the study. Conclusion: This study reports the incidence of major trauma patients with thoracic injury, major trauma patients with rib fractures and the incidence of SSRF in AoNZ. Transport related injuries are the predominant mechanism of injury. The incidence of SSRF was low across AoNZ. To improve the quality of care in AoNZ for major trauma patients with rib fractures, consideration should be made to create national guidelines and robust referral pathways to specialist centres that provide multidisciplinary care including performing SSRF.