Systematic Review and Quality Assessment of Health Economic Evaluation Studies (2007-2019) Conducted in South Korea

Abstract

Background: South Korea formally adopted economic evaluation in December 2006 to aid drug reimbursement decision-making. While this policy change is applied only to pharmaceuticals, it has also sparked interest in economic evaluations for non-pharmaceutical interventions and programmes.

Objective: This study aimed to provide a snapshot of the current practice for published health economic evaluation studies and critically assess the quality of these studies.

Methods: An electronic search was performed on multiple databases (EMBASE, PubMed, NHS Economic Evaluation Database, Scopus, Korean Medical database, Korean studies Information Service System, and Research Information Sharing Service) to identify health economic evaluation studies published between January 2007 and December 2019. The inclusion criteria were peer-reviewed, original health economic evaluations (cost-utility, cost-effectiveness, cost-minimisation, and cost-benefit analyses) published in English or Korean. Two reviewers selected studies for inclusion and extracted data from the included studies. Key characteristics of these studies were descriptively summarised, and study quality was assessed using the Quality of Health Economic Studies (QHES) instrument on a 100-point scale.

Results: A total of 162 studies were included in this review (63 for drugs, 51 for non-pharmaceutical treatments/health technologies, and 48 for health programmes). These numbers confirm a significant increase in the number of publications since the policy introduction. However, the quality of these studies remained relatively low, with a mean QHES score of 57.9 (± 16.0). Study quality also varied substantially, with the QHES scores ranging from 15 to 87. The scores were notably lower in studies with non-pharmaceutical interventions and programmes, cost-effectiveness analyses or cost-benefit analyses, retrospective study-based or simple modelling-based analyses, and those locally published. In addition, a considerable proportion of these studies did not state or specify essential components of economic evaluation, such as perspectives (30.2%), time horizons (29.6%), discount rates (34.6%), and sensitivity analyses (24.7%). While the use of local data either fully or partially was relatively higher for unit costs (94.4%) and resource utilisation (90.1%), it was lower for utility weights (47.1%), treatment effects (63.0%), and baseline risks (70.4%). Transferability or generalisability issues were infrequently discussed when relying on foreign sources. In addition, the included studies were often not well structured, making it difficult to assess their quality.

Conclusion: These findings suggest that there is still much room for improving the quality of health economic evaluation studies conducted in South Korea. Policymakers should critically evaluate available cost-effectiveness evidence, especially for non-pharmaceutical interventions and programmes, when using it for decision-making in South Korea.