Accuracy of SNOMED-CT Chief Presenting Complaint Codes: an audit of 1,000 cases

AIM: The Systematised Nomenclature of Medicine - Clinical Terms (SNOMED-CT) coding system has been introduced to emergency departments in New Zealand, starting with the patient's chief presenting complaint (CPC). However, it is not known how accurate CPC coding at triage is, or whether coding accuracy varies by patient characteristics. The aim of this study was to determine the accuracy of CPC coding. METHOD: We compared the real-time triage recorded CPC with the presenting complaints recorded in medical notes by the treating clinician. Agreement was determined by exact CPC matches and the kappa statistic. RESULTS: From 1,000 consecutive presentations 852 were eligible (89 CPCs). Real-time CPC agreed with clinical notes in 514/852 (60.3%) cases. When real-time free text comments were included, agreement was 732/852 (85.9%). There were no differences by age, sex or ethnicity. Agreement for the common CPCs: 'trauma' (21%); 'abdominal pain' (11%), 'chest pain' 87 (10%) and 'shortness of breath' (8%) was substantial, k=0.66 (95% CI: 0.61, 0.70). Use of non-specific CPC such as 'referral for investigation' (5%) and 'general weakness/fatigue/unwell' (2%) was uncommon but associated with poor agreement. CONCLUSION: The accuracy of real-time coding for CPC using SNOMED-CT was reasonable, except for non-specific CPCs, which should be avoided where possible.