The accuracy of coding for sports-related concussion in New Zealand: An observational study

The aim of this study was to assess the accuracy of the Accident Compensation Corporation codes in a cohort of patients with sports-related concussion. Of particular interest were the codes registered by physiotherapists who may suspect sports-related concussion but are not permitted to diagnose it. Coding accuracy was assessed through review of Accident Compensation Corporation data, clinical notes, and referral letters for a cohort of patients seen in a New Zealand-based sports concussion clinic. Of 296 patients with a clinical diagnosis of sports-related concussion, 51.7% had a concussion-related code. General practitioners coded for concussion in 67.3% of cases for whom they submitted the Accident Compensation Corporation code, District Health Board health professionals (hospitalists) in 47.6%, and physiotherapists in 8.7%. A non-concussion-related code was used by physiotherapists in 87.5% of cases despite them suspecting sports-related concussion as per the study criteria. Use of the Accident Compensation Corporation codes to determine incidence and cost may substantially underestimate the true burden of sports-related concussion. There appears to be an opportunity to improve the accuracy of this coding. Engaging with physiotherapists and improving the process through which health providers are able to update codes are potential strategies.