Drug-Related Problems in Outpatient Prescriptions Across Different Levels of Care in Vietnam: A Multicentre Cross-Sectional Study in a Resource-Constrained Health System

Background: Drug-related problems (DRPs) are a common and largely preventable cause of medication-related harm in outpatient care. The risk is amplified in resource-constrained health systems, where high prescribing workload and limited clinical pharmacy capacity may compromise prescribing quality and medication use. Evidence on the burden and determinants of DRPs across different levels of care remains limited in many low- and middle-income countries, including Vietnam. Objectives: To estimate the prevalence and types of DRPs in outpatient health insurance prescriptions and to identify factors associated with DRP occurrence across facilities at different levels of care in Vietnam. Methods: A multicentre cross-sectional study was conducted using 969 adult outpatient health insurance prescriptions issued between 2023 and 2024 at one provincial general hospital and two district-level health centres. Prescriptions were systematically sampled and retrospectively assessed for DRPs using the national framework issued by the Vietnamese Ministry of Health, which is aligned with Pharmaceutical Care Network Europe concepts. DRPs were categorised into drug selection-related problems and dose- or administration-related problems. Multivariable logistic regression analysis was performed to examine patient-, prescription-, and facility-level factors associated with the presence of at least one DRP. Results: DRPs were identified in 612 prescriptions (63.2%). Dose- and administration-related problems predominated, with inappropriate timing of administration being the most frequent issue (52.5%). Prescriptions containing five or more medicines were significantly more likely to include DRPs than those with fewer medicines (adjusted odds ratio [aOR] 3.41; 95% confidence interval [CI] 2.46-4.72). Digestive system disease diagnoses were strongly associated with DRPs compared with cardiovascular diseases (aOR 11.96; 95% CI 5.27-27.14). Substantial facility-level variation was observed, with one district-level site showing markedly higher odds of DRPs than the provincial hospital (aOR 8.24; 95% CI 4.97-13.64). Conclusions: DRPs were highly prevalent in outpatient prescriptions and were largely driven by preventable dosing and administration issues. The pronounced variation across levels of care highlights inequities in outpatient medication safety and underscores the need for targeted, practice-oriented medication safety strategies and strengthened clinical pharmacy services, particularly in lower-resource district-level settings.