Adverse drug reactions in patients admitted to hospital identified by discharge ICD-10 codes and by spontaneous reports

Aims We studied the international classification of disease (ICD) hospital discharge codes to find unreported adverse drug reactions (ADRs), and asked doctors about their attitudes to reporting some of these cases. Methods We examined the ICD codes assigned on discharge to identify ADRs and compared these with spontaneous reports made to the Committee on Safety of Medicines (CSM). Doctors involved were sent brief resumes of cases and asked if they would report them. Results 49 of 21 365 patient episodes were coded on discharge as ADRs, of which 33 were 'reportable'. Fourteen spontaneous reports were received by the CSM during the same period. The two groups did not overlap. 25 of 60 doctors responded to our questionnaire, and would have reported only 8 of 75 cases outlined. Conclusions The ICD coding allowed us to identify important ADRs which most doctors would not report spontaneously.