Beyond acute care: A time-to-event analysis of injury-related readmissions after a transport-related injury

INTRODUCTION: Injury-related readmissions related to an index injury admission impose significant burden on patients, families, and health systems. Understanding predictors of short-, medium-, and long-term injury-related readmissions can inform strategies to mitigate risk and guide early interventions. This study examines injury-related readmission patterns and predictors among transport-injured patients in Queensland, Australia. METHODS: A population-based, epidemiological data-linkage study was conducted using hospital administrative records for transport-related injury admissions between 2011 and 2021. Index admissions were identified, and subsequent injury-related readmissions were classified using time- and diagnosis-based logic. Outcomes included three time frames for readmissions: within 31-days, 90-days, and 1-year post-discharge. Parametric survival analysis with a Gompertz distribution assessed predictors of injury-related readmission, and dominance analysis quantified the relative importance of these predictors. Predictors spanned six domains: sociodemographic factors, healthcare funder, hospital characteristics, injury-specific attributes, injury mechanism, and geographic factors. RESULTS: Among 89,611 patients with transport-related injury admissions, 7.2% were readmitted for injury-related conditions within 31 days, 10.5% within 90 days, and 17.2% within one year. Mean time-to-readmission was 11, 25, and 92 days for the respective timeframes. Motor vehicle crashes were the most common transport-related injury mechanism, but had the lowest injury-related readmission rates compared to bicycle, motorcycle, and pedestrian injuries. Dominance analysis indicated that injury characteristics, particularly nature of injury, were the strongest predictors of injury-related readmission, with nature, body region and injury mechanism collectively explaining 67.5% to 83.2% of variation across timeframes. CONCLUSION: Injury-related readmissions after transport-related injury occur most frequently within the first month post-discharge but persist up to one year. Injury characteristics dominate predictive influence, suggesting that interventions targeting these factors may reduce both short- and long-term injury-related readmission risk. These findings highlight opportunities for tailored discharge planning and early intervention strategies to alleviate patient and system burden.