Evaluation of the process for reducing medication errors in the outpatient pharmacy, Chaiyaphum Hospital

Abstract

            Medication dispensing error is a critical problem affecting patient safety. The objective of this study was to evaluate the outcome of an error reduction process in the Outpatient Pharmacy dispensing unit at Chaiyaphum Hospital. This was a retrospective before-after study comparing the error rates between the pre-implementation period (July–August 2024) and the post-implementation period (September–October 2024). Research instruments included a data recording form and the HOSxP program. The sample consisted of prescriptions served during official working hours over a total of 80 days. The error reduction process comprised five components: emphasizing dispensing standards, job rotation, improving LASA (Look-Alike, Sound-Alike) drug labeling, preparing prepack medication, and improving drug labeling. Data were analyzed using descriptive statistics, the Mann-Whitney U test, Fisher's exact test, Cohen's d, and Poisson regression.

            The results showed that the error rate significantly decreased from 8.35 pm 5.72 to 4.83 pm 2.57 per 1,000 prescriptions (p < 0.001), representing a 42.2% reduction. The Cohen’s d value of 0.783 indicated a large effect size. All types of errors significantly decreased. Poisson regression analysis found an adjusted IRR (Incidence Rate Ratio) of 0.563 (95% CI: 0.430, 0.736). The process was most effective on days with low to moderate workloads (p = 0.006), while the number of staff was not correlated with the error rate.                       

            The multidimensional error reduction process significantly reduced medication dispensing errors both statistically and clinically. The results of this study can be used as an operational guideline for other hospitals with similar contexts.