Gil-Won Kang

Validity of Self-reported Healthcare Utilization Data in the Community Health Survey in Korea

To evaluate the sensitivity and specificity of Community Health Survey (CHS), we analyzed data from 11,217 participants aged ≥ 19 yr, in 13 cities and counties in 2008. Three healthcare utilization indices (admission, outpatient visits, dental visits) as comparative variables and the insurance benefit claim data of the Health Insurance Review & Assessment Service as the gold-standard were used. The sensitivities of admission, outpatient visits, and dental visits in CHS were 54.8%, 52.1%, and 61.0%, respectively. The specificities were 96.4%, 85.6%, and 82.7%, respectively. This is the first study to evaluate the validity of nationwide health statistics resulting from questionnaire surveys and shows that CHS needs a lot of efforts to reflect the true health status, health behavior, and healthcare utilization of the population.

Public Awareness of Stroke and Its Predicting Factors in Korea: a National Public Telephone Survey, 2012 and 2014

The aim of this study was to investigate time trends in the public awareness of stroke and its predicting factors. The target population was 9,600 community-dwelling adults, aged 19–79 years, in 16 metropolitan cities and provinces in Korea. The survey samples in 2012 and 2014 were selected separately (entirely different sets of subjects) using a proportionate quota sampling method. Information concerning knowledge of stroke and demographics was collected by trained telephone interviewers using random digit dialing. After excluding subjects with a non-response or refusal to answer any question, the analyses included 8,191 subjects in 2012 and 8,127 subjects in 2014. Respondents’ awareness of stroke warning signs (numbness or weakness, difficulty speaking or understanding speech, dizziness, visual impairment, and severe headache) was highest for difficulty speaking or understanding speech (80.9% in 2012 and 86.4% in 2014). There were significant increases in the proportion of respondents understanding the appropriate action (i.e., calling an ambulance) at the time of stroke occurrence (59.6% to 67.1%), and in the proportion aware of the general need for prompt treatment (86.7% to 89.8%). In multivariable logistic regression analysis, older age, higher education level, higher household income, current non-smoking, exposure to stroke-related public relations materials, and experience of stroke education were significantly associated with both high knowledge of stroke warning signs and awareness of the need for prompt treatment. Between 2012 and 2014, the public’s awareness of stroke increased significantly. More specialized interventions, including public relations materials and education, should focus on subgroups who have lower stroke knowledge.

The General Public’s Awareness of Early Symptoms of and Emergency Responses to Acute Myocardial Infarction and Related Factors in South Korea: A National Public Telephone Survey

Background Prompt treatment affects prognosis and survival after acute myocardial infarction (AMI) onset. This study evaluated the awareness of early symptoms of AMI and knowledge of appropriate responses on symptom occurrence, along with related factors. Methods Participants’ knowledge of the early symptoms of and responses to AMI onset were investigated using a random digit dialing survey. We included 9600 residents of 16 metropolitan cities and provinces in Korea. Results The proportions of respondents who were aware of early symptoms of AMI ranged from 32.9% (arm or shoulder pain) to 79.1% (chest pain and discomfort). Of the respondents, 67.0% would call an ambulance if someone showed signs of AMI, 88.7% knew ≥1 symptom, 10.9% knew all five symptoms, and 3.1% had excellent knowledge (correct identification of all five AMI symptoms, not answering “Yes” to the trap question, and correctly identifying calling an ambulance as the appropriate response when someone is exhibiting AMI symptoms). The odds ratio (OR) for having excellent knowledge was significantly higher for those who graduated college or higher (OR 3.42; 95% confidence interval [CI], 1.09–10.76) than for those with less than a primary school education, as well as for subjects with AMI advertisement exposure (OR 1.49; 95% CI, 1.10–2.02) and with knowledge of AMI (OR 1.63; 95% CI, 1.16–2.27). The 60- to 79-year-old group had significantly lower OR for excellent knowledge than the 20- to 39-year-old group (OR 0.53; 95% CI, 0.28–0.99). Conclusions Awareness of AMI symptoms and the appropriate action to take after symptom onset in South Korea was poor. Therefore, educational and promotional strategies to increase the overall awareness in the general public, especially in the elderly and those with low education levels, are needed.

Relationships between Social Support & Social Network and Health Behavior

Objectives : This study aims to explore how social support and social network are related with health behavior. Methods : The target population was 12,449 people in Chungcheongbuk-do. The sample was accrued for the period of 3 months in 2008 by face to face interview of direct visiting from systemat...

Cost-Utility Analysis of Screening Strategies for Diabetic Retinopathy in Korea

This study involved a cost-utility analysis of early diagnosis and treatment of diabetic retinopathy depending on the screening strategy used. The four screening strategies evaluated were no screening, opportunistic examination, systematic fundus photography, and systematic examination by an ophthalmologists. Each strategy was evaluated in 10,000 adults aged 40 yr with newly diagnosed diabetes mellitus (hypothetical cohort). The cost of each strategy was estimated in the perspective of both payer and health care system. The utility was estimated using quality-adjusted life years (QALY). Incremental Cost Effectiveness Ratio (ICER) for the different screening strategies was analyzed. After exclusion of the weakly dominating opportunistic strategy, the ICER of systematic photography was 57,716,867 and that of systematic examination by ophthalmologists was 419,989,046 from the perspective of the healthcare system. According to the results, the systematic strategy is preferable to the opportunistic strategy from the perspective of both a payer and a healthcare system. Although systematic examination by ophthalmologists may have higher utility than systematic photography, it is associated with higher cost. The systematic photography is the best strategy in terms of cost-utility. However systematic examination by ophthalmologists can also be a suitable policy alternative, if the incremental cost is socially acceptable.

Simulation on the Change of Practice Pattern after the Introduction of 7 Diagnosis-related Groups Prospective Payment System in a University Hospital

Seven diagnosis-related groups (DRGs) prospective payment system is going to expand to all hospitals including university hospi-tals this year. However there are few studies on the change of practice pattern under prospective payment system in the university hospital setting. So This study was intended to predict the practice pattern change after the introduction of 7 DRGs prospective payment system in a university hospital setting. To predict the change of practice pattern, this study used simulation technique. Five hundred and nineteen patients classified as 5 DRGs in a university hospital were selected for simulation. The change of practice pat-tern were predicted based on clinicians’ opinion. We also predicted payment change by service items. Major findings of this study are as follows. First, the total medical payment was reduced by 14.4%. The drug payment change (8.8%) took most of total payment reduction. The followings are the change of treatment material cost (3.2%), the change of laboratory tests cost (1.8%), the change of room charge (0.5%), and other payment change (0.1%), respectively. Second, most of the reduction in total medical payment re-sulted from the decreased amount of medical services themselves. The transfer of medical services to outpatient setting took up only 4.9% of the total payment reduction. The change of unit price or composition took up 5.5% of the total payment reduction. In this study we found that it is possible to reduce the inpatient services through practice pattern change in university hospital setting. However, it needs to be careful to adjust DRG payment after the reduction of provided services, because most of reduction was not due to service transfer but to service volume reduction. It is desirable to utilize the saving from practice pattern change as incentive to improve quality of care.Keywords: Diagnosis-related groups; Clinical practice pattern; Patient simulation

Incidence, Prevalence, Mortality and Causes of Death in Systemic Sclerosis in Korea: A Nationwide Population-Based Study.

DEAR EDITOR, While the epidemiology of systemic sclerosis (SSc) is known to vary by geographical region and race, studies at the national level, as well as reports from Asian countries, are scarce, and the majority of existing studies were limited to cases from small geographical areas. The risk of mortality in patients with SSc has been reported to be higher than in the general population. However, most previous studies were based on referral centres, where patients’ severity may be different from that of the general patient population. Therefore, a large-scale population-based study is needed to produce a reliable estimate. In this study, we investigated the incidence, prevalence, mortality and causes of death of patients with SSc in Korea from 2008 to 2013, using the Korean Rare Intractable Disease (RID) registry database linked with the Health Insurance Review and Assessment Services (HIRA) database, which covers the entire Korean population (50 million). To be registered in the RID registry as a patient with SSc, the diagnosis should be made by a physician based on uniform criteria predefined by the government, which are identical to the American College of Rheumatology (ACR) criteria. Also, the diagnosis is reviewed by another healthcare professional in the institution before its final submission to the government. Through this process, we believe the diagnosis is reliable. We defined an incident case as a newly diagnosed and registered patient in the RID registry in that year, with a 2-year washout period. Prevalent cases were defined as all patients with SSc registered in the HIRA-RID database in the corresponding year. Cause of death and vital status of patients with SSc were determined by linking the HIRA-RID database with Statistics Korea, which contains information on the causes of death of all deceased Koreans diagnosed by a physician according to

Diabetes mellitus as a risk factor for glaucoma outcome in Korea.

Editor, R ecently, we experienced a challenging surgical complication we wish to share with the readers. A 49year-old gentleman underwent a Baerveldt BG 103-250 glaucoma implant (Abbott Laboratories Inc., Abbott Park, IL, USA) for uncontrolled primary open-angle glaucoma on his right eye. On postoperative day one, he presented with a flat anterior chamber, low intraocular pressure (IOP) and choroidal folds. After a few days of conservative measures and no improvement, we decided to intervene. The surgical technique involved the exposure of the tube by opening the original conjunctival flap and removal of the scleral patch graft to ascertain that the original 7-0 vicryl suture made to ligate the tube during the primary implantation of the implant was tight and in place. After placing an additional suture to ligate the tube, we noticed a leak around the tube insertion on the sclera. The scleral site was dried with a sterile cotton tip applicator. A 30gauge needle was used to apply a few drops of n-butyl-2-cyanoacrylate tissue adhesive to the tube insertion site, and the anterior chamber was filled with viscoelastic substance (Fig. 1). The tube was covered with a patch graft from cadaver sclera secured with four 10-0 nylon sutures. A few weeks after the surgery, the anterior chamber was deep and the IOP controlled with no medication. The choroidal folds had vanished and the vision improved. Cyanoacrylates are synthetic adhesives with very high tensile strength that rapidly polymerize in the presence of water or blood forming long, strong chains that bond surfaces together.They have been used in ophthalmology to treat corneal perforations, in posterior retinal breaks associated with retinal detachments, for attaching conjunctival autografts after pterygium excision and for closure of filtering bleb leaks in patients with glaucoma (Weiss et al. 1983; Zalta & Wieder 1991; Hartnett & Hirose 1998; Uy et al. 2005). As an alternative to cyanoacrylate, fibrin-based adhesives have been previously used in similar situations. Valimaki (2006) reported the use of fibrin glue to prevent a leak of aqueous around the tube in the immediate postoperative period after glaucoma drainage implant. The glue was used intraoperatively over the scleral flap in eyes with leakage around the tube insertion. They report good IOP control and no complication. As compared to biological adhesives, cyanoacrylate is less expensive and could be used as a safe alternative in places where economic issues are a concern.

Cost-Benefit Analysis of Malaria Chemoprophylaxis and Early Diagnosis for Korean Soldiers in Malaria Risk Regions

Background Chemoprophylaxis has been used to prevent malaria among soldiers and secondary transmission, as it effectively facilitates a decline in disease occurrence and secondary prevention. However, poor compliance and decreased risk of exposure to malaria necessitate that control strategies be reestablished. Methods To predict the incidence of malaria according to a control strategy, we proposed a mathematical model for its transmission using epidemiological data from 2010 to 2012. The benefit component included in the analyses was the averted cost with each control strategy, and the cost components were the cost of implementing chemoprophylaxis and early diagnosis. Results The chemoprophylaxis regimen with hydroxychloroquine sulfate and primaquine was Intervention 1, the regimen with primaquine only was Intervention 2, and diagnosis with a rapid diagnostic test (RDT) kit within 5 days of fever was Intervention 3. The simulation indicated that the combined control program with chemoprophylaxis and early diagnosis would be the most effective strategy, whereas sole early diagnosis would be the least effective strategy. However, the cost-benefit ratio of chemoprophylaxis was less than Intervention 1, irrespective of the varying range of chemoprophylaxis compliance, and that of early diagnosis was more than Intervention 1, regardless of the varying early diagnosis rate and demand for the RDT kit. Although chemoprophylaxis would be more effective at reducing the incidence of malaria than early diagnosis, it is less economical due to the higher cost. Conclusion Our results support the introduction of early diagnosis with a RDT kit to control malaria in the Republic of Korea Army.

ESTIMATION OF THE CUMULATIVE EXPOSURE FREQUENCY AND CUMULATIVE EFFECTIVE DOSE OF DIAGNOSTIC MEDICAL RADIATION IN THE KOREAN POPULATION FROM 2002 TO 2010

Along with increase in the frequency and exposure dose from the diagnostic medical radiation procedures, the publics interest in radiation exposure has also been growing. In this study, in order to estimate the Cumulative Exposure Frequency and the cumulative effective dose of diagnostic medical radiation in the Korean population, we included 680 diagnostic medical radiation procedure codes of the Health Insurance Review & Assessment Services health insurance medical expenses data and adopted the effective dose data from the 2008 report of the United Nations Scientific Committee on the Effects of Atomic Radiation. We combined the data of one million individuals in the national sample cohort database (2002-10) of the National Health Insurance Service. The results revealed that 93.2% (917 972) of the subjects were exposed to diagnostic medical radiation at least once in the past nine years, and the Cumulative Exposure Frequency was 17 286.4 per 1000 individuals with a cumulative effective dose of 5.7 (±17.8) mSv per person. Additionally, 93.1% (854 480) of the subjects had a cumulative effective dose less than 20 mSv, and 0.7% (6139) had a dose that exceeded 100 mSv (extreme), showing that the dosage level was mostly low. However, the number of individuals whose exposure exceeded 100 mSv/y increased 28-fold, from 18 in 2002 to 500 in 2010. In addition, the size of increase also grew each year, suggesting that cancer occurrence due to diagnostic medical radiation may have also increased. In order determine the causal relationship between cancer occurrence and diagnostic medical radiation and setup a guideline for exposure, it is necessary to monitor individual cumulative exposure doses nation-wide and follow up on heavily exposed individuals for an extended period of time.