Poor Identification of Emergency Department Acute Recreational Drug Toxicity Presentations Using Routine Hospital Coding Systems: the Experience in Denmark, Switzerland and the UK

BACKGROUND: Understanding emergency department and healthcare utilisation related to acute recreational drug toxicity (ARDT) generally relies on nationally collated data based on ICD-10 coding. Previous UK studies have shown this poorly captures the true ARDT burden. The aim of this study was to investigate whether this is also the case elsewhere in Europe. METHODS: The Euro-DEN Plus database was interrogated for all presentations 1st July to 31st December 2015 to the EDs in (i) St Thomas’ Hospital, London, UK; (ii) Universitätsspital Basel, Basel, Switzerland; and (iii) Zealand University Hospital, Roskilde, Denmark. Comparison of the drug(s) involved in the presentation with the ICD-10 codes applied to those presentations was undertaken to determine the proportion of cases where the primary/subsequent ICD-10 code(s) were ARDT related. RESULTS: There were 619 presentations over the 6-month period. Two hundred thirteen (34.4%) of those presentations were coded; 89.7% had a primary/subsequent ARDT-related ICD-10 code. One hundred percent of presentations to Roskilde had a primary ARDT ICD-10 code compared to 9.6% and 18.9% in Basel and London respectively. Overall, only 8.5% of the coded presentations had codes that captured all of the drugs that were involved in that presentation. CONCLUSIONS: While the majority of primary and secondary codes applied related to ARDT, often they did not identify the actual drug(s) involved. This was due to both inconsistencies in the ICD‐10 codes applied and lack of ICD‐10 codes for the drugs/NPS. Further work and education is needed to improve consistency of use of current ICD‐10 and future potential ICD‐11 coding systems.