Resource use for older people hospitalised due to injury in a Canadian integrated trauma system: a retrospective multicenter cohort study.

Background: Injuries represent one of the leading causes of preventable morbidity and mortality. For countries with ageing populations, admissions of injured older patients are increasing exponentially. Yet, we know little about hospital resource use for injured older patients. Our primary objective was to evaluate inter-hospital variation in the risk-adjusted resource use for injured older patients. Secondary objectives were to identify the determinants of resource use and evaluate its association with clinical outcomes. Methods: We conducted a multicenter retrospective cohort study of injured older patients (>= 65 years) admitted to any trauma centres in the province of Quebec (2013-2016, N=33,184). Resource use was estimated using activity-based costing and modelled with multilevel linear models. We conducted separate subgroup analyses for patients with trauma and fragility fractures. Results: Risk-adjusted resource use varied significantly across trauma centres, more for older patients with fragility fractures (intra-class correlation coefficients [ICC]=0.093, 95% CI [0.079, 0.102]) than with trauma (ICC=0.047, 95% CI=0.035-0.051). Risk-adjusted resource use increased with age, and the number of comorbidities, and varied with discharge destination (P <0.001). Higher hospital resource use was associated with higher incidence of complications for trauma (Pearson correlation coefficient [r]=0.5, 95% CI=0.3-0.7) and fragility fractures (r =0.5, 95% CI=0.3-0.7) and with higher mortality for fragility fractures (r =0.4, 95% CI=0.2-0.6). Conclusions: We observed significant inter-hospital variations in resource use for injured older patients. Hospitals with higher resource use did not have better clinical outcomes. Hospital resource use may not always positively impact patient care and outcomes. Future studies should evaluate mechanisms, by which hospital resource use impacts care.