Cost implications of adverse drug event-related emergency department visits – a multicenter study in South Korea

ABSTRACT

Background

Adverse drug reactions (ADRs) increase health-care resource utilization, including that for emergency department (ED) visits. However, cost analyses of ADRs resulting in ED visits are scarce. Therefore, we aimed to estimate the direct medical costs before and after ADR occurrence and analyzed the cost-driving factors.

Methods

The ADR cases were identified by a retrospective review of medical records of patients who visited the ED of three tertiary hospitals in South Korea from July to December 2014. The direct medical cost was estimated by the difference in costs six months before and after the ED visit. A generalized linear model was used to identify the ADR-associated cost-driving factors.

Results

The mean cost per ADR increased by 26.1% (±SD = 4.3) during the six-month follow-up compared with that during the six months before the ED visit (p < 0.05). Preventable ADRs accounted for approximately 19.9% of the cost increase among all ADR cases. The regression analysis revealed that ‘ADR-related hospitalization’ was a significant (p < 0.05) factor leading to an increase in the direct medical costs.

Conclusion

Drug-related ED visits increase the burden on health insurance systems and patients’ out-of-pocket costs, mostly due to the hospitalization costs.

KEYWORDS:

• Adverse drug event
• direct medical cost
• emergency department
• pharmacoepidemiology

Article highlights box

• Tertiary emergency department (ED) visits due to adverse drug events (ADEs) increased the direct medical costs by 26.1% during a six-month follow-up compared to the costs incurred six months before the visit.

• After ED visits for ADEs, the inpatient costs increased by 28.0% and outpatient costs by 7.0%. ADE-related hospitalization was the greatest cost-driving factor for direct medical costs after ADEs.

• ‘ADR-related hospitalization’ was the statistically significant factor of cost increase by ADR in our regression analysis.

• Co-payment by a patient and non-insurance costs increased by 56.0% and 41.3%, respectively, whereas the health insurance benefits increased by 16.7%. Drug-related ED visits increased the burden on patients’ out-of-pocket costs compared to the health insurance system costs.

• 16.6% of the ADR cases were preventable according to Schumock’s criteria. Preventing these ADRs would allow cost savings of up to 19.9% of all ADR-induced costs in our study population.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Data availability

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.

Authors contributions

SH Kim and EK Lee designed the study protocols and supervised the whole study. JY Lee, MG Kang, HK Park and Jae-woo Jung helped the data collection. HK Park took an active role in reviewing paper and interpretation of data. MS Lee conducted cost analysis and drafted the manuscript. All authors approve this version of manuscript and agree to be accountable for all aspects of the work.

Additional information

Funding

This study was supported by a research grant from the Korea Institute of Drug Safety & Risk Management (2016-2017).