Prevalence, contributing factors, and interventions to reduce medication errors in outpatient and ambulatory settings: a systematic review

BACKGROUND: Medication errors are common events that compromise patient safety. Outpatient and ambulatory settings enhance access to healthcare which has been linked to favorable outcomes. While medication errors have been extensively researched in inpatient settings, there is dearth of literature from outpatient settings.

AIM: To synthesize the peer-reviewed literature on the prevalence, nature, contributory factors, and interventions to minimize medication errors in outpatient and ambulatory settings.

METHOD: A systematic review was conducted using Medline, Embase, CINAHL, and Google Scholar which were searched from 2011 to November 2021. Quality assessment was conducted using the quality assessment checklist for prevalence studies tool. Data related to contributory factors were synthesized according to Reason's accident causation model.

RESULTS: Twenty-four articles were included in the review. Medication errors were common in outpatient and ambulatory settings (23-92% of prescribed drugs). Prescribing errors were the most common type of errors reported (up to 91% of the prescribed drugs, high variations in the data), with dosing errors being most prevalent (up to 41% of the prescribed drugs). Latent conditions, largely due to inadequate knowledge, were common contributory factors followed by active failures. The seven studies that discussed interventions were of poor quality and none used a randomized design.

CONCLUSION: Medication errors (particularly prescribing errors and dosing errors) in outpatient settings are prevalent, although reported prevalence range is wide. Future research should be informed by behavioral theories and should use high quality designs. These interventions should encompass system-level strategies, multidisciplinary collaborations, effective integration of pharmacists, health information technology, and educational programs.