Antecedents of Severe and Nonsevere Medication Errors


Dr. Yun-Kyung Chang, School of Nursing, University of North Carolina at Chapel Hill, P.O. Box 27599–7460, Chapel Hill, NC 27599.E-mail:


Purpose: To investigate if differences in antecedents of severe and nonsevere medication errors exist.

Design: A longitudinal study of 6 months of data from 279 nursing units in 146 randomly selected hospitals in the United States (US).

Methods: Antecedents of severe and nonsevere medication errors included work environment factors (work dynamics and RN hours), team factors (communication with physicians and nurses' expertise), person factors (nurses' education and experience), patient factors (age, health status, and previous hospitalization), and medication-related support services. Generalized estimating equations with a negative binomial distribution were used with nursing units as the unit of analysis.

Findings: None of the antecedents allowed predicting both types of medication errors. Nurses' expertise had a negative and medication-related support services had a positive association with nonsevere medication errors. Nurses' educational level had a significant nonlinear relationship with severe medication errors only: As the percentage of unit BSN-prepared nurses increased, severe medication errors decreased until the percentage of BSN-prepared nurses reached 54%. In contrast, RN experience had a statistically significant relationship with nonsevere medication errors only and nursing units with more experienced nurses reported more nonsevere medication errors.

Conclusions: Severe and nonsevere medication errors might have different antecedents.

Clinical Relevance: Error prevention and management strategies should be targeted to specific types of medication errors for best results.