Effect of the elderly and increasing injury severity on acute hospital resource utilization in a cohort of inner city trauma patients.

OBJECTIVE This study aimed to determine the relative effect of elderly patients and increasing injury severity on acute hospital costs and inpatient length of stay. METHODS A prospective study of all trauma team activations at a single inner city trauma centre was conducted over a 1-year period. Costs were imputed using Australian Refined Diagnosis-Related Groups. Costs and inpatient length of stays were compared between elderly (age ≥65 years) and non-elderly patients. Relative effects of increasing injury severity score (ISS) and age categories were modelled using generalized linear regression. RESULTS Over the study period, 1096 consecutive patients were studied. Falls were the most common mechanism and contributed the highest proportion of aggregate costs. There was a moderately high correlation between cost and ISS (Spearman's rank correlation coefficient 0.65, P < 0.001). Median costs for elderly patients were around three times higher than that for non-elderly patients and median length of stay was over twice that of non-elderly patients (7 days versus 3 days, P < 0.001). After adjusting for injury severity, the predicted costs of elderly trauma patients were around 30% higher compared with non-elderly patients. An increasing effect of injury severity on cost was observed across minor and major trauma. CONCLUSION Both injury severity and elderly patients have a significant impact on acute hospital costs across the spectrum of major and minor trauma.