Validity and reliability of observational methods for studying medication administration errors

The validity and reliability of observational methods for studying medicati on administration errors (MAEs) were studied. Between January and June 1998, two pharmacists observed consecutive drug ad ministration rounds by nurses on two wards in a U.K. hospital and recorded all MAEs identified. The observers intervened in cases of potentially harmf ul errors. MAE records were audited to determine the percentage of omitted doses for which a corresponding reason was documented for the observation p eriods and for nonobservation periods. Error rates for each drug administra tion round were analyzed according to whether they were for the nurse's fir st, second, third (and so on) observed round. Error rates were calculated b efore and after the first intervention with nurses for whom an intervention was made. Observer reliability was calculated by comparing the rates of er rors identified by the two observers. There was no difference between the observation and nonobservation periods in the percentage of omitted doses for which a reason was documented, and t here was no change in the error rate with repeated observations. There was no difference in error rates before and after the first intervention for ea ch nurse. There was also no difference in error detection between the two o bservers and no change with increasing duration of observation. Observation of nurses during drug administration at a U.K. hospital did not significantly affect the MAE rate; nor did tactful interventions by the ob servers. Observer reliability was high. Concerns about the validity and rel iability of observational methods for identifying MAEs may be unfounded.