Data Sources
This study utilized two data sources from the government system. The prevalence rates of eating disorders were calculated using data from Health Insurance Review & Assessment Service (HIRA). The database provided records of patient numbers, specifying outpatient, inpatient, and hospitalization days by gender. The economic burden of eating disorders was derived from the data of National Health Insurance Services (NHIS), which is the single insurer of South Korea (Seong et al., 2017). The NHIS provides medical costs based on the medical utilization records from the National Health Information Database (NHID). Data from both HIRA and NHIS were taken from January 1, 2010 to December 31, 2015. Population statistics were adopted from the Korean Statistical Information Service (KOSIS). Average currency rates per year were adopted from the Bank of Korea (http://ecos.bok.or.kr) to convert the Korean Won to US dollars (USD). The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
Case Definition
Eating disorders (F50) are defined using the International Classification of Diseases, Tenth Revision (ICD-10). For estimation of the economic burden, eating disorders were as: anorexia nervosa (F50.0); bulimia nervosa (F50.2); and other eating disorders (F50.1 – F50.9). Other eating disorders included atypical anorexia nervosa (F50.1); atypical bulimia nervosa (F50.3); overeating associated with other psychological disturbances (F50.4); vomiting associated with other psychological disturbances (F50.5); other eating disorders (F50.8); and unspecified eating disorder (F50.9).
Prevalence Rates of Easting Disorderder
The prevalence rates of eating disorders from 2010 to 2015 were estimated using figures of the number of cases from Health Insurance Review & Assessment Service. The number of cases was divided by the total population and then multiplied by 100,000.
Estimation Of The Economic Burden Of Eating Disorders
The present study estimated the economic burden of eating disorders (anorexia nervosa, bulimia nervosa, other eating disorders) using a prevalence-based approach from NHIS data.
Direct costs were estimated by taking the sum of medical costs, transportation costs of hospital visits, and caregiver costs. Medical costs included non-covered care costs, insured and non-insured costs, and drug costs. To estimate hospital transportation costs, round-trip transportation costs were taken from the Korean Health Panel. Also, caregiver costs were calculated using data from the Korea Patient Helper Society.
Indirect cost-2 was estimated to explain productivity loss caused by the absence from work for hospital admissions or outpatient visits. Indirect costs-2 was included in the total costs. For sensitivity purpose, indirect cost-1 was estimated. Indirect costs-1 was calculated by taking lost productivity into account. Productivity lost was defined as the loss of ones’ time due to medical care. To estimate the productivity lost we used time spent travelling to hospital and waiting for treatment and multiplied the average time spent by the average daily wage. For example, when a patient took the day off due to hospitalization, it was considered as the loss of one day’s income. In case of an outpatient visit, it was considered as the loss of one-third of daily income. Patients aged less than 20 years were excluded. Indirect costs-1 was not included in the total costs. Total economic cost was taken as the sum of direct and indirect costs.
All analyses were performed using SAS (ver. 9.4; SAS institute, Cary, NC, USA).
Ethics Statement
Ethical review was obtained by a University review board (IRB No. KHSIRB-19-354 (EA)). Informed consent was exempted due to the public nature of the data sources of NHIS.