Quantitative exploration of medication errors among older people: a systematic review

Background: Medication errors (MEs) in older people are of importance due to global aging patterns. Following on from aging-related changes in pharmacokinetics, pharmacodynamics, and the potential presence of multiple comorbidities treated with polypharmacy, older people are highly vulnerable to the effects and consequences of MEs.

Objective: The primary outcome of this study was to systematically review studies on the incidence and categories of MEs in older people. Secondary outcomes included economic and clinical consequences of MEs in older people, risk factors for MEs in older people, and medications involved.

Methods: A comprehensive, electronic search was conducted using PubMed, EBSCOhost, OvidMedline and Proquest central databases for studies evaluating MEs in older people published in peer-reviewed journals before November 2017. A secondary manual search was also conducted by checking the bibliographies of included studies to identify other relevant studies. There was no limitation imposed on the language, time of publication, or the setting in which the study was carried out. The quality of identified studies was assessed based on 17 criteria adopted from Alsulami et al. and Metsälä et al. The results were categorized using the phases of medication use when the error was detected or occurred.

Results: Eighteen studies met the inclusion criteria with a total of 467,193 participants from 11 countries. Identified MEs were administration errors [number of times ME subcategory was reported (n = 7); error frequency rate 1.2–59.0%], prescribing errors (n = 7; 1.6–49.7%), transcribing errors (n = 5; 15.0–70.2%), reconciliation errors (n = 4; 5.0–53.6%), and dispensing errors (n = 2; 2.0–14.0%). People with polypharmacy had the highest tendency of MEs. Three studies reported severe clinical consequences from MEs ranging from 2.9% to 13.0%. The main category of medications involved in MEs were cardiovascular medications (n = 15); nervous system medications (n = 11); and medications for the alimentary tract and metabolism (n = 8).

Conclusions: Administration and prescribing errors were the most frequently reported MEs in older people. Medication classes that were most commonly reported in the context of MEs in older people were cardiovascular medications and nervous system medications. We identified polypharmacy as a risk factor for MEs, which was found to correlate with the number of MEs in many stages of medication use. A lack of studies from Asia, Latin America, and Africa highlights the need for future research in these regions.