OBJECTIVES: Medication errors are widely recognized as significant contributors to patient harm and sources of preventable healthcare expenditure. This framework proposes a methodology for estimating the epidemiology and economic burden of medication errors within the US acute care setting.

METHODS: A literature analysis was conducted to review (1) definitions and classifications of medication errors (2) rates of medications errors (3) costs of medication errors. Relevant literature was used to develop a framework to estimate costs associated with medication errors. A sub-section of the framework was tested to assess the costs associated with adverse drug events due to IV preparation and administration errors from a healthcare system perspective.

RESULTS: We identified a number of discrete error types that could be classified under five broad categories: (1) Prescription (2) Translation/Verification (3) Preparation (4) Administration (5) Monitoring. Each error type has a probability of occurrence and of patient harm. Additionally, each instance of patient harm is associated with a financial cost weighted based on the severity of harm. The aggregated costs approximate the economic burden of acute care medication errors from a healthcare system perspective. Our base-case analysis considered a 400-bed hospital (85% average daily census), compounding an average of 1 IV infusion per patient per day, to assess costs resulting from patient harm. This decision tree analysis estimated a total of 1015 preparation and/or administration errors resulting in an annual cost of $4.7 million. The limitations of this analysis result from heterogeneity within the published literature including varied risk rates and costs, definitions of outcomes, non-generalizable patient populations or settings, and varied time horizons.

CONCLUSIONS: Medication errors are a clinical and economic burden to the US healthcare system. This framework may serve as a tool to estimate costs of medication errors, and help healthcare systems prioritize system-level medication safety programs.