Medication errors in United States hospitals

This study evaluated hospital demographics, staffing, pharmacy variables, h ealth care outcomes measures (severity of illness-adjusted mortality rates, drug costs, total cost of care, and length of stay) and medication errors. A database was constructed from the 1992 American Hospital Association's A bridged Guide to the Health Care Field, the 1992 National Clinical Pharmacy Services database, and 1992 mortality data from the Health Care Financing Administration. Simple statistical tests and a severity of illness-adjusted multiple regression analysis were employed. The study population consisted of 1116 hospitals that reported information on medication errors and 913 h ospitals that reported information on medication errors that adversely affe cted patient care outcomes. We evaluated factors associated with the 430,58 6 medication errors and 17,338 medication errors that adversely affected pa tient care outcomes. Medication errors occurred in 5.07% of the patients ad mitted each year to these hospitals. Each hospital experienced a medication error every 22.7 hours (every 19.73 admissions). Medication errors that ad versely affected patient care outcomes occurred in 0.25% of all patients ad mitted to these hospitals/year. Each hospital experienced a medication erro r that adversely affected patient care outcomes every 19.23 days (or every 401 admissions). The following factors were associated with increased medic ation errors/occupied bed/year: lack of pharmacy teaching affiliation (slop e = 0.8875, p=0.0416), centralized pharmacists (slope = 1.0942, p=0.0001), number of registered nurses/occupied bed (slope = 1.624, p=0.032), number o f registered pharmacists/occupied bed (slope = 25.0573, p=0.0001), hospital mortality rate (slope = 2.8017, p=0.0192), and total cost of care/occupied bed/year (slope = 0.01432, p=0.0091). Factors associated with decreased me dication errors were location in the Mid-Atlantic census region (slope = -1 .5182, p=0.03), affiliation with a pharmacy teaching program (slope = -1.02 52, p=0.0349), decentralized pharmacists (slope = -0.9843, p=0.0037), and n umber of medical residents/occupied bed (slope = -1.478, p=0.0014). There w as a 45% decrease in medication errors (1.81-fold decrease) in hospitals th at had decentralized pharmacists, compared with hospitals that had centrali zed pharmacists. in addition, there was a 94% decrease in medication errors that adversely affected patient care outcomes (16.88-fold decrease) in hos pitals that had decentralized pharmacists compared with hospitals that had only centralized pharmacists. Based on previous field studies and our findi ngs in 1116 hospitals, it appears that one of the most effective ways to pr event or reduce medication errors is to decentralize pharmacists to patient care areas. The results of this study should help hospitals reduce the num ber of medication errors that occur each year.