Tillmann BW, Nathens AB, Guttman MP, et al. - As high rates of undertriage and overtriage complicate the identification of patients who require transfer from non–trauma centers to trauma centers (secondary triage), researchers here investigated differences in secondary triage accuracy across non–trauma centers and sought for factors linked with highly accurate secondary triage. In this population-based study, they assessed 118,973 injured patients who presented at 182 non–trauma centers in a large regional trauma system and categorized them as undertriaged, overtriaged, or appropriately triaged based on transfer status and presence of a severe injury (Injury Severity Score > 15, death within 24 hours, or critical injury as defined by the American College of Surgeons). Observations revealed significant variation in triage accuracy across non–trauma centers, after adjusting for hospital resources. No transfer to a trauma center (undertriaged) was made in the majority (76.9%) of severely injured patients, while there were 9.6% of nonseverely injured patients who were transferred to a trauma center (overtriaged). The mixed-effect models suggest that at the average hospital, severely injured patients vs nonseverely injured patients had 3.76 times higher likelihood of being transferred. Findings suggest the role of other potentially modifiable factors in transfer decisions.