Model-based cost-effectiveness analysis of interventions aimed at preventing medication error at hospital admission...

Medication errors can lead to preventable adverse drug events (pADEs) that have significant cost and health implications. Errors often occur at care interfaces, and various interventions have been devised to reduce medication errors at the point of admission to hospital. The aim of this study is to assess the incremental costs and effects [measured as quality adjusted life years (QALYs)] of a range of such interventions for which evidence of effectiveness exists.

A previously published medication errors model was adapted to describe the pathway of errors occurring at admission through to the occurrence of pADEs. The baseline model was populated using literature-based values, and then calibrated to observed outputs. Evidence of effects was derived from a systematic review of interventions aimed at preventing medication error at hospital admission.

All five interventions, for which evidence of effectiveness was identified, are estimated to be extremely cost-effective when compared with the baseline scenario. Pharmacist-led reconciliation intervention has the highest expected net benefits, and a probability of being cost-effective of over 60% by a QALY value of pound10 000.

The medication errors model provides reasonably strong evidence that some form of intervention to improve medicines reconciliation is a cost-effective use of NHS resources. The variation in the reported effectiveness of the few identified studies of medication error interventions illustrates the need for extreme attention to detail in the development of interventions, but also in their evaluation and may justify the primary evaluation of more than one specification of included interventions.