Ki-Hong Chun

Cardiovascular Risk Factors for Incident Hypertension in the Prehypertensive Population

OBJECTIVES The aim of this study was to investigate the effect of changes in cardiovascular disease (CVD) risk factors on progression from prehypertension (PreHTN) to hypertension (HTN) using an 8-yr prospective Korean Cancer Prevention Study (KCPS) by the National Health Insurance Corporation (NHIC) in Korea. METHODS A total of 16,229 subjects, aged 30 to 54, with new onset preHTN at baseline (1994-1996) in a biennial national medical exam were selected and followed up till 2004 at 2-yr intervals. All subjects underwent a biennial health examination including biochemical measurements and behavior. The log-rank test was performed to assess the relationship between changes in CVD risk factors and progression to HTN. The Cox proportional hazard model was used to identify factors influencing progression to HTN. RESULTS With regards the progression rate in men, ex-smokers (42.9%), abstainers (37.5%), and regular exercisers (37.6%) showed a slower progression rate than continuous smokers (49.5%) and continuous drinkers (50.9%). In women, those who participated in regular exercise (22.6%) had a lower rate of progression than continuous non-exercisers (36.1%). According to the results of the Cox proportional hazard model, improvements in smoking (hazard ratio [HR], 0.756), drinking (HR, 0.669), regular exercise (HR, 0.653), body mass index (HR, 0.715), and total cholesterol (HR, 0.788) played a protective role in progression to HTN in men, while in women, participating in regular exercise (HR, 0.534) was beneficial. CONCLUSION Improvements in CVD-related behaviors diminished the progression rate of HTN. This study suggests that individuals with PreHTN should be targeted for specific health behavioral intervention to prevent the progression of HTN.

Determinants of health care expenditures and the contribution of associated factors: 16 cities and provinces in Korea, 2003-2010.

Objectives The purpose of this study was to classify determinants of cost increases into two categories, negotiable factors and non-negotiable factors, in order to identify the determinants of health care expenditure increases and to clarify the contribution of associated factors selected based on a literature review. Methods The data in this analysis was from the statistical yearbooks of National Health Insurance Service, the Economic Index from Statistics Korea and regional statistical yearbooks. The unit of analysis was the annual growth rate of variables of 16 cities and provinces from 2003 to 2010. First, multiple regression was used to identify the determinants of health care expenditures. We then used hierarchical multiple regression to calculate the contribution of associated factors. The changes of coefficients (R2) of predictors, which were entered into this analysis step by step based on the empirical evidence of the investigator could explain the contribution of predictors to increased medical cost. Results Health spending was mainly associated with the proportion of the elderly population, but the Medicare Economic Index (MEI) showed an inverse association. The contribution of predictors was as follows: the proportion of elderly in the population (22.4%), gross domestic product (GDP) per capita (4.5%), MEI (-12%), and other predictors (less than 1%). Conclusions As Baby Boomers enter retirement, an increasing proportion of the population aged 65 and over and the GDP will continue to increase, thus accelerating the inflation of health care expenditures and precipitating a crisis in the health insurance system. Policy makers should consider providing comprehensive health services by an accountable care organization to achieve cost savings while ensuring high-quality care.

Cost-effectiveness of drug-eluting vs. bare-metal stents in patients with coronary artery disease from the Korean National Health Insurance Database.

Purpose The aim of this study was to evaluate the cost-effectiveness of the use of drug-eluting stents (DESs), as compared with bare-metal stents (BMSs) in Korea. Materials and Methods A retrospective cohort study was conducted between January 2000 and December 2007. Subjects were stent-treated for the first time between 2004 and 2005, with four years of follow-up (2004-2007) (n=43674). The incremental cost-effectiveness ratio (ICER) was used to calculate the costs of DESs compared with BMSs among patients with coronary artery disease (CAD). Cost-effectiveness was assessed with effectiveness defined as a reduction in major adverse cardiac events after six months and after one, two, three, and four years. Results The total costs of a DESs were 674108 Korean won (KRW) higher than that of a BMSs at the end of the follow-up; 13635 thousand KRW per patient treated with DESs and 12960 thousand KRW per patient treated with BMSs. The ICER was 256315 per KRW/death avoided and 293090 per KRW/re-stenting avoided among the CAD patients at the end of the follow-up. Conclusion The ICER for the high-risk patients was lower than that for the low-risk patients. The use of DESs is clinically more useful than the use of BMSs for CAD and myocardial infarction patients, especially for those considered to be high-risk patients in Korea.

Sex Difference of Type 2 Diabetes Affected by Abdominal Obesity versus Overall Obesity

Purpose This research compares the predictive value of the abdominal obesity indicator, waist circumference (WC), and the overall obesity indicator, body mass index (BMI), among men and women with regard to type 2 diabetes. Materials and Methods This study used data collected from 4,400 households selected by a stratified multistage probability sampling method during the 2001 Korea National Health and Nutrition Examination Survey (KNHANES). The final study sample included 4,684 subjects over 30 years of age who had completed the health examination required for the analysis of the health interview and health behavior surveys. Results Both men and women showed significant differences in fasting blood glucose (FBG) or HbA1c levels based on abdominal obesity irrespective of BMI. However, the presence of overall obesity among men with abdominal obesity was not significantly correlated with FBG or HbA1c levels, while the presence of overall obesity among women with abdominal obesity was significantly different in regard to FBG or HbA1c levels. Conclusion Both WC and BMI emerged as a measures of risk factors for type 2 diabetes among women while only WC emerged as a risk factor for diabetes among men.

Moderating effects of interactions between dietary intake and socioeconomic status on the prevalence of metabolic syndrome

PURPOSE The purpose of this study is to examine how nutrients can affect the relationship between the development of metabolic syndrome (MS) and socioeconomic factors. METHODS This study was based on data obtained from the 2005 Korea National Health and Nutrition Examination Survey was conducted as a health survey of nationally representative samples of non-institutionalized Korean. The final sample was composed of 3146 people over 40 years of age. RESULTS The relationship between the prevalence of MS and socioeconomic factors was associated with the consumption of nutrients. The slope of the graphs increased sequentially from the 1st quintile to 5th quintile of nutrient consumption. However, the directions of the 4th and 5th quintile were reversed from that of the 1st, 2nd, and 3rd quintile in reference to the horizontal axis. That is, the 1st, 2nd, and 3rd quintiles indicate that higher household income was associated with lower prevalence of MS. However, the plots for the 4th and 5th quintile indicate that higher the household income was associated with higher the prevalence of MS. This tendency was shown in all the models that yielded statistically significant confirmation of moderating effects. CONCLUSIONS The association between the prevalence of MS and different socioeconomic status varies according to the level of nutrient consumption.

Does Abdominal Obesity Accelerate the Effect of Hypertriglyceridemia on Impaired Fasting Glucose

Purpose This study sought to determine whether abdominal obesity is a risk factor for impaired fasting glucose (IFG) and hypertriglyceridemia and to verify whether moderate effect of abdominal obesity on the relationship between IFG and hypertriglyceridemia in Korea. Materials and Methods Data from the Korean National Health and Nutrition Examination Survey was used for the analysis. The study population included 5,938 subjects aged 20 year old drawn from non-diabetic participants in a health examination survey. The subjects were classified according to the presence of abdominal obesity based on waist circumference, IFG based on their fasting blood glucose level, and hypertriglyceridemia on their fasting triglyceride. Results The multivariate-adjusted odds ratios for the occurrence of hypertriglyceridemia were 2.91 in the abdominal obesity group as compared with the nonobesity group and 1.31 in subjects with IFG compared with the normoglycemia controls. Abdominal obesity was found to be positively moderated in the interaction between waist circumference and fasting blood sugar. Conclusion The moderate effect between abdominal obesity and IFG contributes to the development of hypertriglyceridemia in Korea.

Factors Contributing to Increases in Prescription Drug Expenditures Borne by National Health Insurance in South Korea.

Purpose Rapid growth of prescription drug expenditures is a problem in South Korea. The objective of this study was to assess the contributions of four variables (therapeutic choice, drug-mix, original use, and price changes) to increases in drug expenditures paid by the National Health Insurance (NHI) in Korea. Materials and Methods A retrospective cohort study was conducted between January 1, 2008 and June 30, 2012 utilizing data from the NHI Claims Database of the Health Insurance Review and Assessment Service. The number of target drug types for final analysis was 13959. To analyze the growth rates of drug expenditures, this study used Fisher ideal index and the Laspeyres and Paasche indexes. Results With the exception of 2012, therapeutic choice contributed to about 40–60% of the increase in drug expenditures every year, while drug-mix contributed to another 30–40%. Conclusion The rapid growth in prescription drug expenditure was found to be largely due to drug-mix and therapeutic choice over time. Original use had little impact on drug spending.

The Trend of the Specialization of Hospitals in 2003 to 2005 in Metropolitan Cities

This study examined the changes in the service mix of Korean hospitals in 6 metropolitan cities between 2003 and 2005, and assessed whether the sample hospitals exhibit consistent trend or chance variation in multiple years. Three measures of hospital service mix, focusing on the specialization of services, were applied: information theory index, internal Herfindahl index, and number of distinct diagnosis-related groups (DRGs) treated. National Health Insurance claims were used to calculate the indexes. Specialization indexes were calculated in each year, and then examined to identify the pattern over time. Kappa analysis was applied to assess the agreements of specialization score between two years after hospitals were categorized into 4 groups with quartiles. Kappa score showed that the service mix of hospitals were changed during the study years. Specialization scores were increased given the market structure for three years. Hospitals which showed higher or lower specialization scores than the average of the scores consistently classified into the same group. Specialization indexes showed relatively consistent pattern over 3 years, and such consistencies were evident for hospitals regardless of the specialization status. Policy makers can identify the degree of specialization with the indexes, and it could provide a picture of how hospital services were mixed and changed over time.

A National Chronic Disease Management Model and Evaluation of Validity of Primary Care Physician(PCP) Model in Korea

This study suggests a model for continuing and comprehensive management of hypertension or Type 2 diabetes mellitus (T2DM) in Korea. Moreover, this paper computed the contribution cost of hypertension or T2DM management using the healthcare medical cost, which could have occurred from stroke, myocardial infarction (MI), and end-stage renal disease (ESRD) that were successfully prevented from the effective hypertension or T2DM management. Additionally, these costs were compared with the cost of implementing the hypertension or T2DM management model suggested in this study. This study used the medical fee summary of the health insurance claims submitted to National Health Insurance Corporation by medical facilities for services provided during the period from January 1st 1999 to December 31st 2006. The prevalence rate with treatment referred to cases in which patients submitted their medical claims at least once during the period, along with an accordant diagnosis. The incidence rate with treatment referred to cases in which patients who never submitted claims for the accordant disease during the five years from 1999 to 2003 submitted claims for the accordant disease in 2004 and 2005. The relative risk of the occurrence of stroke, MI and ESRD was 11.0, 13.6, and 30.3, respectively. The attributable risk of hypertension or T2DM for stroke was 0.730, and that for MI and ESRD were 0.773 and 0.888, respectively. Based on these, the contribution cost of hypertension or T2DM is estimated to be 986.3 billion Korean Won(KRW) for stroke patients, 330.5 billion KRW for MI patients, and 561.7 billion KRW for ESRD patients as in 2005. Hence, the total contribution cost of hypertension or T2DM to stroke, MI, and ESRD is 1.878 trillion KRW. The estimate for operational costs included an annual expenditure of 50,000 KRW per each recipient and an annual subsidy of 0.22 million KRW per person for the 1.6 million low.income individuals with hypertension or T2DM to cover their out.of.pocket medical expenses. Under this assumption, it took approximately 0.6 trillion KRW to manage 5 million high.risk patients in the low. and mid.income range, coverings up to 50% of costs. In conclusion, considering the potential benefits of preventing stroke, MI, and ESRD, the costs seems to be reasonable.