Rianne J. Zaal

The influence that electronic prescribing has on medication errors and preventable adverse drug events : an interrupted time-series study

OBJECTIVE This study evaluated the effect of a Computerized Physician Order Entry system with basic Clinical Decision Support (CPOE/CDSS) on the incidence of medication errors (MEs) and preventable adverse drug events (pADEs). DESIGN Interrupted time-series design. MEASUREMENTS The primary outcome measurements comprised the percentage of medication orders with one or more MEs and the percentage of patients with one or more pADEs. RESULTS Pre-implementation, the mean percentage of medication orders containing at least one ME was 55%, whereas this became 17% post-implementation. The introduction of CPOE/CDSS has led to a significant immediate absolute reduction of 40.3% (95% CI: -45.13%; -35.48%) in medication orders with one or more errors. Pre-implementation, the mean percentage of admitted patients experiencing at least one pADE was 15.5%, as opposed to 7.3% post-implementation. However, this decrease could not be attributed to the introduction of CPOE/CDSS: taking into consideration the interrupted time-series design, the immediate change was not significant (-0.42%, 95% CI: -15.52%; 14.68%) because of the observed underlying negative trend during the pre-CPOE period of -4.04% [95% CI: -7.70%; -0.38%] per month. CONCLUSIONS This study has shown that CPOE/CDSS reduces the incidence of medication errors. However, a direct effect on actual patient harm (pADEs) was not demonstrated.

Comparison of potential risk factors for medication errors with and without patient harm

To compare determinants for medication errors leading to patient harm with determinants for medication errors without patient harm.