Out-of-Pocket(OOP) Expenditure for Prescription Drugs among South Korean Outpatients under the National Health Insurance System: Focus on Chronic Diseases Including Diabetes

Abstract

Abstract Introduction: There is substantial concern about the increasing number of obese children and adolescents, resulting in continuing risks for chronic conditions such as diabetes. This study was aimed at estimating the annual expense of out-of-pocket prescription drugs (OOP-PD) attributable to chronic diseases in adult outpatients in South Korea.

Method: Korea Health Panel Survey (KHPS) data from 2008–2009 were used. Chronic diseases such as diabetes, hypertension, asthma and osteoarthritis were included in analyzing OOP-PD expenses. The annual OOPPD expenses were defined as total amount paid per person during one year in 2008, for prescription drugs not listed in the national formulary and the legal copayment portion (30%) for formulary-listed prescription drugs in outpatient settings. Relationship of chronic diseases to OOP-PD expenses was analyzed using a generalized linear model with a log link function.

Result: A total of 12,082 subjects were analyzed. Subjects having three or more chronic diseases showed OOP-PD values that were 5-times higher than those without any chronic diseases. Diabetes was the chronic disease contributing the most to OOP-PD expenses. The cost ratio (CR) in diabetic subjects without concurrent chronic diseases (i.e., hypertension, osteoarthritis, and asthma) was 6.1 as compared to those without chronic diseases, followed by subjects with asthma (CR = 4.7), hypertension (CR = 4.0), two or more concurrent chronic diseases but no diabetes (CR = 4.2), and osteoarthritis (CR = 2.0).

Conclusion: High OOP-PD values serve as a proxy for the total healthcare expenditure in patients with chronic disease, especially diabetes. These costs might encourage accelerated prevention programs among populations at higher risks in South Korea public health point of view, as in many countries encountering budget constraints in recent years.