Reducing dispensing errors in Swedish pharmacies: the impact of a barrier in the computer system

Since 2004, a web-based reporting system enables monitoring of dispensing errors in all Swedish pharmacies. The adoption of this system was followed by an overall increase in reports, mainly explained by the dispensing of medicines of improper strength. In 2006 an intervention was implemented, aimed at reducing these errors. The objective of this study was to assess the impact of the intervention on the number of errors.

Monthly data on the reported number of dispensing errors from July 2004 until December 2007 were used. These were analysed in total and subdivided by type and cause of error. A time-series design was applied, and linear segmented regression analysis used to analyse whether changes in slope or level occurred; shifts in intercept or slope where p<0.01 were considered as statistically significant.

The intervention coincided with a distinct decrease in error reports and a statistically significant change in slope that switched from a slight increase, 0.09, to a decrease, -0.26 (p = 0.0035). Medicines dispensed with wrong strength also displayed a significant change in slope, from 0.08 to -0.27 (p<0.0001), as well as dispensing errors caused by registration failure, that is, failure of the registration of a prescription in pharmacy computers, which changed from 0.05 to -0.29 (p<0.0001).

The intervention was associated with a decrease in the number of reports on drugs dispensed with the wrong strength, but also had a decreasing effect on errors caused by registration failure and on the dispensing errors in total as well.