The accuracy of International Classification of Diseases coding for dental problems not associated with trauma in a hospital emergency department

Objectives Emergency department (ED) visits for nontraumatic dental conditions (NTDCs) may be a sign of unmet need for dental care. The objective of this study was to determine the accuracy of the International Classification of Diseases codes (ICD-10-CA) for ED visits for NTDC. Methods ED visits in 2008-2099 at one hospital in Toronto were identified if the discharge diagnosis in the administrative database system was an ICD-10-CA code for a NTDC (K00-K14). A random sample of 100 visits was selected, and the medical records for these visits were reviewed by a dentist. The description of the clinical signs and symptoms were evaluated, and a diagnosis was assigned. This diagnosis was compared with the diagnosis assigned by the physician and the code assigned to the visit. Results The 100 ED visits reviewed were associated with 16 different ICD-10-CA codes for NTDC. Only 2 percent of these visits were clearly caused by trauma. The code K0887 (toothache) was the most frequent diagnostic code (31 percent). We found 43.3 percent disagreement on the discharge diagnosis reported by the physician, and 58.0 percent disagreement on the code in the administrative database assigned by the abstractor, compared with what it was suggested by the dentist reviewing the chart. Conclusion There are substantial discrepancies between the ICD-10-CA diagnosis assigned in administrative databases and the diagnosis assigned by a dentist reviewing the chart retrospectively. However, ICD-10-CA codes can be used to accurately identify ED visits for NTDC.