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Kenneth N Barker

Publications and source records attributed to Kenneth N Barker.

5 recordsLinked to original sources

Geometric probability distribution for modeling of error risk during prescription dispensing.

PURPOSE: The relationship between the number of prescriptions dispensed by individual pharmacy staff during a single workday and the probability of committing at least one dispensing error during that same workday period was evaluated using a geometric probability distribution. SUMMARY: A cross-sectional descriptive study involving 50 pharmacies located in six cities across the United States was conducted. A pharmacist trained to detect dispensing errors recorded the number of prescriptions filled by each pharmacy staff member and noted which prescription represented the staff member's first dispensing error (defined as any deviation from the prescriber's order) made during the observation period. The Kolmogorov-Smirnov tests for discrete distributions revealed that the observed cumulative distribution of dispensing errors could have come from a geometric probability distribution that assumed dispensing error rates of 2-3%. In terms of risk analysis, this study's findings suggest that there can be a quantifiable statistical relationship between a measure of workload and the risk of committing at least one dispensing error. The ability to model dispensing errors using a geometric probability distribution enables the safety and health care practitioner to directly assess dispensing error risk as a function of a pharmacy's accuracy rate and the number of prescriptions a pharmacy staff member should dispense during a work shift. CONCLUSION: A geometric probability distribution effectively modeled the relationship between the number of prescriptions filled and the occurrence of the first dispensing errors.

Drug Prescriptions↗

Medication errors observed in 36 health care facilities.

BACKGROUND: Medication errors are a national concern. OBJECTIVE: To identify the prevalence of medication errors (doses administered differently than ordered). DESIGN: A prospective cohort study. SETTING: Hospitals accredited by the Joint Commission on Accreditation of Healthcare Organizations, nonaccredited hospitals, and skilled nursing facilities in Georgia and Colorado. PARTICIPANTS: A stratified random sample of 36 institutions. Twenty-six declined, with random replacement. Medication doses given (or omitted) during at least 1 medication pass during a 1- to 4-day period by nurses on high medication-volume nursing units. The target sample was 50 day-shift doses per nursing unit or until all doses for that medication pass were administered. METHODS: Medication errors were witnessed by observation, and verified by a research pharmacist (E.A.F.). Clinical significance was judged by an expert panel of physicians. MAIN OUTCOME MEASURE: Medication errors reaching patients. RESULTS: In the 36 institutions, 19% of the doses (605/3216) were in error. The most frequent errors by category were wrong time (43%), omission (30%), wrong dose (17%), and unauthorized drug (4%). Seven percent of the errors were judged potential adverse drug events. There was no significant difference between error rates in the 3 settings (P =.82) or by size (P =.39). Error rates were higher in Colorado than in Georgia (P =.04) CONCLUSIONS: Medication errors were common (nearly 1 of every 5 doses in the typical hospital and skilled nursing facility). The percentage of errors rated potentially harmful was 7%, or more than 40 per day in a typical 300-patient facility. The problem of defective medication administration systems, although varied, is widespread.

Accreditation↗

Comparison of methods for detecting medication errors in 36 hospitals and skilled-nursing facilities.

The validity and cost-effectiveness of three methods for detecting medication errors were examined. A stratified random sample of 36 hospitals and skilled-nursing facilities in Colorado and Georgia was selected. Medication administration errors were detected by registered nurses (R.N.s), licensed practical nurses (L.P.N.s), and pharmacy technicians from these facilities using three methods: incident report review, chart review, and direct observation. Each dose evaluated was compared with the prescriber's order. Deviations were considered errors. Efficiency was measured by the time spent evaluating each dose. A pharmacist performed an independent determination of errors to assess the accuracy of each data collector. Clinical significance was judged by a panel of physicians. Observers detected 300 of 457 pharmacist-confirmed errors made on 2556 doses (11.7% error rate) compared with 17 errors detected by chart reviewers (0.7% error rate), and 1 error detected by incident report review (0.04% error rate). All errors detected involved the same 2556 doses. All chart reviewers and 7 of 10 observers achieved at least good comparability with the pharmacist's results. The mean cost of error detection per dose was $4.82 for direct observation and $0.63 for chart review. The technician was the least expensive observer at $2.87 per dose evaluated. R.N.s were the least expensive chart reviewers at $0.50 per dose. Of 457 errors, 35 (8%) were deemed potentially clinically significant; 71% of these were detected by direct observation. Direct observation was more efficient and accurate than reviewing charts and incident reports in detecting medication errors. Pharmacy technicians were more efficient and accurate than R.N.s and L.P.N.s in collecting data about medication errors.

Chi-Square Distribution↗

National observational study of prescription dispensing accuracy and safety in 50 pharmacies.

OBJECTIVES: To measure dispensing accuracy rates in 50 pharmacies located in 6 cities across the United States and describe the nature and frequency of the errors detected. DESIGN: Cross-sectional descriptive study. SETTINGS: Chain, independent, and health-system pharmacies (located in hospitals or managed care organizations). PARTICIPANTS: Pharmacy staff at randomly selected pharmacies in each city who accepted an invitation to participate. INTERVENTION: Observation by a pharmacist in each pharmacy for 1 day, with a goal of inspecting 100 prescriptions for dispensing errors (defined as any deviation from the prescriber's order). MAIN OUTCOME MEASURE: Dispensing errors on new and refill prescriptions. RESULTS: Data were collected between July 2000 and April 2001. The overall dispensing accuracy rate was 98.3% (77 errors among 4,481 prescriptions; range, 87.2%-100.0%; 95.0% confidence interval, +/- 0.4%). Accuracy rates did not differ significantly by pharmacy type or city. Of the 77 identified errors, 5 (6.5%) were judged to be clinically important. CONCLUSION: Dispensing errors are a problem on a national level, at a rate of about 4 errors per day in a pharmacy filling 250 prescriptions daily. An estimated 51.5 million errors occur during the filling of 3 billion prescriptions each year.

Drug Labeling↗