What is the impact of introducing inpatient electronic prescribing on prescribing errors? A naturalistic stepped wedge study in an English teaching hospital

Most studies evaluating the impact of electronic prescribing on prescribing safety have used comparatively weak study designs such as uncontrolled before-and-after studies. This study aimed to apply a more robust naturalistic stepped wedge study design to compare the prevalence and types of prescribing errors for electronic prescribing and paper prescribing. Data were collected weekly during a phased electronic prescribing implementation across 20 wards in a large English hospital. We identified 511 (7.8%) erroneous orders in 6523 paper medication orders, and 312 (6.0%) in 5237 electronic prescribing orders. Logistic regression suggested no statistically significant effect of electronic prescribing use or of study week; patient and ward had significant effects. Errors involving incorrect doses and illegible or incomplete orders were less common with electronic prescribing; those involving duplication, omission, incorrect drug and incorrect formulation were more common. Actions are needed to mitigate these error types; future studies should give more consideration to the effects of patient and ward.