Coding traumatic brain injury with the abbreviated injury scale following a standardised radiologic template will improve classification of trauma populations

Introduction: Injury coding with the Abbreviated Injury Scale (AIS) is an important element for benchmarking, trauma registries and research. Objective: To compare the severity of traumatic brain injury (TBI) coding derived from the AIS with or without the use of a standardised radiologic template. Methods: A retrospective two-centre cohort study including patients aged ≥ 18 years with isolated TBI admitted to an intensive care between 2011 and 2016 was conducted. TBI was re-coded to conform the AIS by coders, and CT-brain imaging was reassessed by a neuro-radiologist following a standardised radiologic template from which AIS codes were derived. Results: A total of 560 patients were included (median age 57, 37% female). The percentage of MAIS ≥ 4 and major trauma was higher when AIS coding for TBI was derived from a standardised radiologic template vs. coding without (n = 456 (81.4%) and n = 374 (66.8%), p < 0.001; n = 441 (78.8%) and n = 352 (62.9%), p < 0.001, respectively). There was an inter-centre difference in the proportion of MAIS ≥ 4 re-coded without a standardised radiologic template (n = 212 (68.2%) and n = 140 (56.2%), p = 0.004), and no difference when re-coded with the template (n = 251 (80.7%) and n = 190 (76.3%), p = 0.206). Conclusion: Coding TBI with AIS based on a standardised radiologic template results in fewer missed AIS head codes, more detailed AIS head codes, and more patients classified as ‘major trauma’. Key Points: Question Radiologic reports are an important source for injury coding with the abbreviated injury scale (AIS) and are often not sufficiently specific. Findings An AIS-based standardised radiologic template for reporting resulted in more detailed AIS head codes and more patients classified as major trauma. Clinical relevance Injury coding with the AIS based on a standardised radiologic template will improve exchanging medical information in the acute health care setting and classification of trauma populations.