Abstract: | The aim of this study was to determine when medication administration errors (MAEs) are most likely to occur. MAEs were identified by observing nurses preparing and administering medication on a care of the elderly ward during two eight-day periods. The exposure of individual patients to MAEs was also determined. A total of 119 MAEs was identified during the observation of 2,170 opportunities for error, representing an error rate of 5.5 per cent (95 per cent confidence interval, 4.5 per cent to 6.4 per cent). The omission of drugs that were not available on the ward was the predominant type of error. Of the 56 study patients, 35 experienced at least one MAE during the study period. Errors occurred at an average rate of at least 0.3 errors per patient day. The MAE rate was significantly higher on weekdays (6.4 per cent) than during weekends (4.0 per cent) and higher during pharmacy opening hours (7.8 per cent) than when the pharmacy was closed (4.6 per cent). Patients were at greatest risk of MAEs in the first 48 hours of admission and in the first 48 hours after prescribing. A multidisciplinary approach is required to design safer systems. |