Preventing medication errors in community pharmacy: frequency and seriousness of medication errors

Background: Medication errors are a widespread problem which can, in the worst case, cause harm to patients. Errors can be corrected if documented and evaluated as a part of quality improvement. The Danish community pharmacies are committed to recording prescription corrections, dispensing errors and dispensing near misses. This study investigated the frequency and seriousness of these errors. Methods: 40 randomly selected Danish community pharmacies collected data for a defined period. The data included four types of written report of incidents, three of which already existed at the pharmacies: prescription correction, dispensing near misses and dispensing errors. Data for the fourth type of report, on adverse drug events, were collected through a web-based reporting system piloted for the project. Results: There were 976 cases of prescription corrections, 229 cases of near misses, 203 cases of dispensing errors and 198 cases of adverse drug events. The error rate was 23/10 000 prescriptions for prescription corrections, 1/10 000 for dispensing errors and 2/10 000 for near misses. The errors that reached the patients were pooled for separate analysis. Most of these errors, and the potentially most serious ones, occurred in the transcription stage of the dispensing process. Conclusion: Prescribing errors were the most frequent type of error reported. Errors that reached the patients were not frequent, but most of them were potentially harmful, and the absolute number of medication errors was high, as provision of medicine is a frequent event in primary care in Denmark. Patient safety could be further improved by optimising the opportunity to learn from the incidents described.