Objective Dosing errors can cause significant harm in paediatric healthcare settings. Our objective was to investigate the effects of paediatric dose range checking (DRC) clinical decision support (CDS) software on overdosing-related outcomes.

Methods A before-after study and a semistructured survey of prescribers was conducted across inpatient wards (excluding intensive care) in a regional children’s hospital. DRC CDS software linked to a paediatric drug formulary was integrated into an existing electronic prescribing system. The main outcome measures were; the proportion of prescriptions with overdosing errors; overdosing-related clinical incidents; severity of clinical incidents; and acceptability of the intervention.

Results The prescription overdosing error rate did not change significantly following the introduction of DRC CDS software: in the preintervention period 12/847 (1.4%) prescriptions resulted in prescription errors and in the postintervention period there were 9/684 (1.3%) prescription overdosing errors (n=21, Pearson χ² value=0.028, p=0.868). However, there was a significant trend towards a reduction in the severity of harm associated with reported overdosing incidents (n=60, Mann-Whitney U value=301.0, p=0.012). Prescribers reported that the intervention was beneficial and they were also able to identify factors that may have contributed to the persistence of overdosing errors.

Conclusion DRC CDS software did not reduce the incidence of prescription overdosing errors in a paediatric hospital setting but the level of harm associated with the overdosing errors may have been reduced. Use of the software seemed to be safe and it was perceived to be beneficial by prescribers.