Dispensing error rates in pharmacy: A systematic review and meta-analysis

Dispensing errors can cause preventable patient harm such as adverse drug events, hospitalisation, or death. The aim of this study was to systematically review the literature and quantify the global prevalence of dispensing errors across pharmacy settings. Electronic databases including EMBASE, MEDLINE, and CINAHL were searched between January 2010 and September 2023. Studies published in English, from all pharmacy settings, with data that could be used to calculate the prevalence of dispensing errors were included. Studies were excluded if they did not report true dispensing errors. Data including study characteristics and dispensing error characteristics were extracted. The quality of the studies was assessed using 10 criteria. Random-effects meta-analysis was employed to estimate pooled prevalences and heterogeneity was quantified using the I2 statistic. Subgroup analyses were performed according to sample size, study design, setting, error identification method, location, and study quality. PROSPERO: CRD42020197860. Of the 4216 articles, 62 studies were included. Hospital was the most common pharmacy setting (n = 44, 71.0%) and 15 studies were based in the community. The type of denominator used to report dispensing errors varied between studies, such as dispensed items (n = 45, 72.6%), doses (n = 7, 11.3%), or patients (n = 5, 8.1%). The prevalence of dispensing errors ranged from 0 to 33.3% (n = 62 studies with 64 prevalence estimates). The pooled prevalence for dispensing errors across all studies was 1.6% (95% CI 1.2%–2.1%, I2 = 100%). A majority of studies were of moderate methodological quality (n = 36, 58.1%) and interrater reliability was applied in eight studies. The worldwide prevalence of dispensing errors was 1.6% across community, hospital and other pharmacy settings. This varied depending on the type of denominator used, study design and how the error was identified. This review highlights the need for consistent definitions and standardised classifications of dispensing errors worldwide to reduce heterogeneity.