Development and Validation of a Hospital Indicator of Activity-Based Costs for Injury Admissions

Objectives: To develop a hospital indicator of resource use for injury admissions. Methods: We focused on resource use for acute injury care and therefore adopted a hospital perspective. We included patients ≥16 years old with an Injury Severity Score >9 admitted to any of the 57 trauma centers of an inclusive Canadian trauma system from 2014 to 2018. We extracted data from the trauma registry and hospital financial reports and estimated resource use with activity-based costing. We developed risk-adjustment models by trauma center designation level (I/II and III/IV) for the whole sample, traumatic brain injuries, thoraco-abdominal injuries, orthopedic injuries, and patients ≥65 years old. Candidate variables were selected using bootstrap resampling. We performed benchmarking by comparing the adjusted mean cost in each center, obtained using shrinkage estimates, to the provincial mean. Results: We included 38 713 patients. The models explained between 12% and 36% (optimism-corrected r²) of the variation in resource use. In the whole sample and in all subgroups, we identified centers with higher- or lower-than-expected resource use across level I/II and III/IV centers. Conclusions: We propose an algorithm to produce the indicator using data routinely collected in trauma registries to prompt targeted exploration of potential areas for improvement in resource use for injury admissions. The r² of our models suggest that between 64% and 88% of the variation in resource use for injury care is dictated by factors other than patient baseline risk.