Trends in pneumonia and influenza-associated hospitalizations in South Korea, 2002-2005.

Pneumonia and influenza are leading causes of morbidity and mortality across the globe. Korea has established the national health-insurance system to cover the entire Korean population since 1989. The aim of this study was to describe the epidemiologic trends in pneumonia and influenza-associated hospitalizations and deaths using the Korean National Health Insurance databases and national vital statistics. During 2002-2005, 989,472 hospitalizations and 10,543 deaths due to pneumonia and influenza were recorded. Eighty-one percent of the hospitalizations were related to diagnoses with unspecified aetiology. The average annual rate of hospitalizations due to pneumonia and influenza was 5.2 per 1,000 people [95% confidence interval (CI) 5.2-5.3], and the hospitalization rate increased by 28% (from 4.5 to 5.8 per 1,000 people) during the four-year study period. In addition, deaths due to pneumonia and influenza increased by 48% (2,829 during 2003, 3,522 during 2004, and 4,192 during 2005). Overall, the national burden of hospitalizations and deaths due to pneumonia and influenza in Korea was high, and it increased for all age-groups during the study period. A comprehensive review of potential interventions by the government authorities should aim to reduce the burden of pneumonia and influenza.

Inequalities in medical care utilization by South Korean cancer patients according to income: a retrospective cohort study.

This study explores income inequalities in the utilization of medical care by cancer patients in South Korea, according to type of medical facilities and survival duration. The five-year retrospective cohort study used data drawn from the Korean Cancer Registry, the National Health Insurance database, and the death database of the Korean National Statistical Office. The sample consisted of 43,433 patients diagnosed with cancer in 1999. The authors found significant quantitative inequalities as a function of income in the patients' utilization of medical care. Cancer patients from the highest income class used inpatient and outpatient care more frequently than did patients from the lowest income class. Those with higher incomes tended to use more inpatient and outpatient services at major tertiary hospitals, which were known as providing better medical care than other types of hospitals and clinics. Moreover, horizontal inequality in cancer-care expenditures favoring those with higher incomes was observed during earlier periods of treatment. In conclusion, income substantially affects the utilization of inpatient and outpatient services, amount of medical expenditures, and type of medical facilities.

Modeling of Statistical Variation Effects on DRAM Sense Amplifier Offset Voltage.

With the downscaling in device sizes, process-induced parameter variation has emerged as one of the most serious problems. In particular, the parameter fluctuation of the dynamic random access memory (DRAM) sense amplifiers causes an offset voltage, leading to sensing failure. Previous studies indicate that the threshold voltage mismatch between the paired transistors of a sense amplifier is the most critical factor. In this study, virtual wafers were generated, including statistical VT variation. Then, we numerically investigate the prediction accuracy and reliability of the offset voltage of DRAM wafers using test point measurement for the first time. We expect that this study will be helpful in strengthening the in-line controllability of wafers to secure the DRAM sensing margin.

Body-mass index and mortality in Korean men and women.

BACKGROUND: Obesity is associated with diverse health risks, but the role of body weight as a risk factor for death remains controversial. METHODS: We examined the association between body weight and the risk of death in a 12-year prospective cohort study of 1,213,829 Koreans between the ages of 30 and 95 years. We examined 82,372 deaths from any cause and 48,731 deaths from specific diseases (including 29,123 from cancer, 16,426 from atherosclerotic cardiovascular disease, and 3362 from respiratory disease) in relation to the body-mass index (BMI) (the weight in kilograms divided by the square of the height in meters). RESULTS: In both sexes, the average baseline BMI was 23.2, and the rate of death from any cause had a J-shaped association with the BMI, regardless of cigarette-smoking history. The risk of death from any cause was lowest among patients with a BMI of 23.0 to 24.9. In all groups, the risk of death from respiratory causes was higher among subjects with a lower BMI, and the risk of death from atherosclerotic cardiovascular disease or cancer was higher among subjects with a higher BMI. The relative risk of death associated with BMI declined with increasing age. CONCLUSIONS: Underweight, overweight, and obese men and women had higher rates of death than men and women of normal weight. The association of BMI with death varied according to the cause of death and was modified by age, sex, and smoking history.

Body mass index and serum aminotransferase levels in Korean men and women.

BACKGROUND AND AIMS: Obesity has been postulated as contributing to the risk of nonalcoholic steatohepatitis. With the surging obesity epidemic, an ensuing epidemic of nonalcoholic steatohepatitis and its sequelae is of concern. The objectives of this clinical research study were to examine the association between body mass index (BMI) and serum aminotransferase levels. METHOD: A study was carried out on 1,166,847 Koreans (731,560 men and 435,287 women), 30 to 95 years of age, who received health insurance from the National Health Insurance Corp and had a biennial medical evaluation from 1992 to 1995. RESULTS: Across the range of BMI values (<18.5 to >or=32 kg/m) in men, alanine aminotransferase (ALT) was estimated to increase by 18.8 U/L and aspartate aminotransferase (AST) increased by 7.1 U/L. In women, ALT increased by 9.9 U/L, whereas AST increased by 4.5 U/L. In men, interactions between BMI and alcohol consumption were significant (P<0.001) for ALT and AST, but the degree of effect modification was quantitatively minor. However, ALT and AST levels were somewhat higher in heavy alcohol drinkers than in nondrinkers. For women, the relationship of aminotransferase levels with BMI did not vary by alcohol consumption. The relationship of BMI with aminotransferase weakened with increasing age. CONCLUSIONS: In Korea, ALT and AST are strongly associated with BMI and increased progressively from the lowest to the highest strata of BMI. The association of BMI with aminotransferase levels was modified by age and sex.

Caregiver burden among caregivers of Koreans with dementia.

BACKGROUND: Most studies on caregiver burden have been conducted in Western countries, while few studies on the correlates of caregiver burden have been performed in Korea. OBJECTIVE: To suggest better policies for the care of dementia patients by using a nationwide database to identify factors that affect caregiver burden in Korea. METHODS: The database of the Korean National Health Insurance (KNHI) and National Medical Aid (NMA) programs, which covers all Koreans, was used. A sample of 609 dementia patients and their caregivers was selected from a total of 85,281 dementia patients in 2004 and interviewed to evaluate the total cost of care and caregiver burden. Stepwise multiple linear regression analysis was then performed to identify significant independent predictors of caregiver burden. RESULTS: Among caregiver-related factors, caregiver burden was higher in those who were female, had a history of home care during the previous year, and had less education. Among patient-related factors, poor ADL/IADL function was significant. The most interesting result was that subjective sense of socioeconomic status (good/fair/poor) was a stronger predictor of caregiver outcome than actual economic costs. CONCLUSION: The results of this study suggest that interventions to assist patients with dementia should focus on female caregivers, especially those considered likely to be suffering from an economic burden. Interventions should also aim to improve the ADL and IADL capacities of patients.

Pancreatic cancer and factors associated with the insulin resistance syndrome in the Korean cancer prevention study.

There is increasing evidence that type 2 diabetes mellitus and glucose intolerance are a cause, not just a consequence, of pancreatic cancer. We examined whether other factors that characterize the insulin resistance syndrome are also risk factors for pancreatic cancer in a prospective cohort study of 631,172 men and women (ages 45+ years) who received health insurance from the Korean Medical Insurance Corporation. The biennial medical evaluations from 1992 to 1995 provided the baseline information for this study. Relative risks (RR) were estimated using proportional hazards models adjusted for age, sex, smoking, and fasting serum glucose (after excluding the first 2 years of follow-up). There were 2,194 incident cases of pancreatic cancer diagnosed in the cohort over a median follow-up of 12 years. There was no evidence that pancreatic cancer risk was associated with total cholesterol, systolic blood pressure, WBC count, or body mass index. Abnormal levels of aspartate aminotransferase and alanine aminotransferase were both associated with a moderately increased risk of developing the disease (40+ versus <20; RR, 1.33; 95% CI, 1.14-1.55; P(trend) = 0.05 and RR, 1.34; 95% CI, 1.16-1.56; P(trend) = 0.02, respectively). Excluding 6 years of follow-up reduced this RR (95% CI) for aspartate aminotransferase to 1.22 (1.01-1.49), but even after excluding 10 years follow-up the RR (95% CI) for alanine aminotransferase was unchanged [1.36 (1.01-1.83)]. Although fasting serum glucose has been found previously to be associated with pancreatic cancer risk in this cohort, most other factors that characterize insulin resistance syndrome were not associated with pancreatic cancer risk. The association with elevated liver enzyme levels is a novel finding that warrants further investigation.

Disparities in antihypertensive medication adherence in persons with disabilities and without disabilities: results of a Korean population-based study.

OBJECTIVE: To determine disparities in antihypertensive medication adherence between persons with disabilities and those without disabilities in South Korea. DESIGN: The study compared antihypertensive medication adherence between persons with disabilities and those without disabilities using medical claims data of the National Health Insurance (NHI). SETTING: We obtained data from claims submitted to the NHI, which covers almost the entire Korean population. Persons who were prescribed antihypertensive medication during the calendar year 2004 were identified. PARTICIPANTS: The study comprised data from persons with disabilities (n=85,098) and persons without disabilities (n=2,368,636). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A cumulative medication adherence (CMA) greater than or equal to 80% was defined as an appropriate medication adherence. Multiple logistic regression was used to identify differences in antihypertensive medication adherence between persons with disabilities and without disabilities. Estimates were adjusted for demographic characteristics (sex, age), type of medical insurance, insurance contribution a month as a proxy for household income, residential area, and clinical characteristics (medication duration, comorbid conditions). RESULTS: People with disabilities had lower CMAs than those without (median CMA, 83.6% vs 85.7%; appropriate medication adherence, 54.5% vs 57.5%). Results of the multiple logistic regression adjusting other factors indicated that people with disabilities had decreased probabilities of appropriate adherence. CONCLUSIONS: Medication adherence is reduced by various types of disability and impairment such as those involving mobility and communication. Much effort should be made to investigate how and why these disparities take place and develop health policies to remove these disparities if they exist.

The National Health Insurance system as one type of new typology: the case of South Korea and Taiwan.

A typology is the useful way of understanding the key frameworks of health care system. With many different criteria of health care system, several typologies have been introduced and applied to each country's health care system. Among those, National Health Service (NHS), Social Health Insurance (SHI), and Private Health Insurance (PHI) are three most well-known types of health care system in the 3-model typology. Differentiated from the existing 3-model typology of health care system, South Korea and Taiwan implemented new concept of National Health Insurance (NHI) system. Since none of previous typologies can be applied to these countries' NHI to explain its unique features in a proper manner, a new typology needs to be introduced. Therefore, this paper introduces a new typology with two crucial variables that are 'state administration for health care financing' and 'main body for health care provision'. With these two variables, the world's national health care systems can be divided into four types of model: NHS, SHI, NHI, and PHI (Liberal model). This research outlines the rationale of developing new typology and introduces main features and frameworks of the NHI that South Korea and Taiwan implemented in the 1990 s.

Analyzing the Historical Development and Transition of the Korean Health Care System.

OBJECTIVES: Many economically advanced countries have attempted to minimize public expenditures and pursue privatization based on the principles of neo-liberalism. However, Korea has moved contrary to this global trend. This study examines why and how the Korean health care system was formed, developed, and transformed into an integrated, single-insurer, National Health Insurance (NHI) system. METHODS: We describe the transition in the Korean health care system using an analytical framework that incorporates such critical variables as government economic development strategies and the relationships among social forces, state autonomy, and state power. This study focuses on how the relationships among social forces can change as a nation's economic development or governing strategy changes in response to changes in international circumstances such as globalization. RESULTS: The corporatist Social Health Insurance (SHI) system (multiple insurers) introduced in 1977 was transformed into the single-insurer NHI in July 2000. These changes were influenced externally by globalization and internally by political democratization, keeping Korea's private-dominant health care provision system unchanged over several decades. CONCLUSION: Major changes such as integration reform occurred, when high levels of state autonomy were ensured. The state's power (its policy capability), based on health care infrastructures, acts to limit the direction of any change in the health care system because it is very difficult to build the infrastructure for a health care system in a short timeframe.

The effect of aging on mastication and swallowing parameters according to the hardness change of solid food.

As part of the aging process, multiple oral physiologic changes occur and these changes may cause individuals to reduce food intake or switch the types of food texture. Thus, the need to develop food products for the elderly has increased. To evaluate the suitability of the food products for the elderly, the evaluation method should be verified and it is important to identify the parameters of mastication and swallowing. Therefore, the purpose of this study was to compare the differences of mastication and swallowing parameters between the young adults and the elderly depending on the varying hardness of rice food product. Subjects included 20 young adults and 40 elderly and bolus transit times of video-fluoroscopic swallowing study (VFSS) were used. Four types of rice products with different hardness were provided including cooked rice, soft-boiled rice, rice gruel and thin rice gruel. In the elderly group, the chewing number, oral processing time, post-faucial aggregation time, valleculae aggregation time (VAT), first subsequence duration and total duration were significantly different according to the changes in food hardness. Of the bolus transit times, the VAT and the second subsequence duration (S-S2) were significantly different between the two groups. These results suggest that VAT and S-S2, key VFSS parameters, as well as the chewing number and total duration are useful tools for evaluating the effect of aging on mastication and swallowing of solid foods. PRACTICAL APPLICATIONS: In Korea, the aging population is rapidly increasing. According to recent surveys, a large number of elderly Koreans have reported chewing difficulties and many of them are in the state of under-nutrition. As aging progresses, multiple physiologic changes occur in mastication and swallowing functions. These changes may cause individuals to reduce their food intake or switch to soft food products. Therefore, the development of texture-modified food products for the elderly is needed and they should be developed based on the understandings of the physiology of mastication and swallowing according to different rheological properties of food products consumed in Korea, which are quite different from those of the western countries. In this study, we compared the differences of mastication and swallowing parameters between the young adults and the elderly depending on the varying hardness of rice food product.

Suicide risk in relation to social class: a national register-based study of adult suicides in Korea, 1999-2001.

BACKGROUND: Few controlled studies have examined social class as a risk factor for suicide in Korea. AIM: The objective of the present study was to investigate the effects of social class on suicide risk in Korea. METHODS: A case-control design was constructed from cause-of-death statistics for the period 1999 to 2001, in Korea, as published by the Korean National Statistical Office. The cases were defined as people aged between 20 and 64 who died by suicide, while the controls were defined as those who died of natural causes in the same age groups. RESULTS AND CONCLUSIONS: The proportions and odds ratios for suicide were higher in young people than in elderly people, and higher for divorced subjects than for cohabitants. They were also higher for residents of rural areas, as opposed to residents of Seoul and other metropolitan areas, and for people in social classes III and IV, than they were for those in social class I. To control the variables that influence risk of suicide, such as age, marital status and area of residence, we used multiple logistic regression. Compared with class I, risk of suicide was higher in social classes III and IV, in both sexes. The principal conclusion of this study is that, regardless of sex, lower social class constitutes a high risk for suicide in Korea, even after controlling for variables such as age, marital status and area of residence. We conclude that a well-controlled and balanced social welfare system could reduce suicide risk, especially among people in lower social class.

Nurse-Perceived Patient Adverse Events depend on Nursing Workload.

OBJECTIVES: The purpose of this study was to investigate the correlation between nursing workload and nurse-perceived patient adverse events. METHODS: A total of 1,816 nurses working in general inpatient units of 23 tertiary general hospitals in South Korea were surveyed, and collected data were analyzed through multilevel logistic regression analysis. RESULTS: Among variables related to nursing workload, the non-nursing task experience had an influence on all four types of patient adverse events. Nurses with non-nursing tasks experienced patient adverse events-falls [odds ratio (OR) = 1.31], nosocomial infections (OR = 1.23), pressure sores (OR = 1.16), and medication errors (OR = 1.23)-more often than occasionally. In addition, when the bed to nurse ratio was higher, nurses experienced cases of pressure sores more often (OR = 1.35). By contrast, nurses who said the nursing workforce is sufficient were less likely than others to experience cases of pressure sores (OR = 0.78). Hospitals with a relatively high proportion of nurses who perceived the nursing workforce to be sufficient showed a low rate of medication error (OR = 0.28). CONCLUSION: The study suggested that the high level of nursing workload in South Korea increases the possibility of patient adverse events.

Equity in utilization of cancer inpatient services by income classes.

Equity in health care services has been prioritized on the Korean government's policy agenda since the government-driven national health insurance achieved universal coverage in 1989 along with the final inclusion of the self-employed as beneficiaries. The purpose of this study is to identify disparities in the utilization of health care services, especially cancer inpatient services among different income groups in Jeju Island of South Korea. We analyzed the national health insurance data about qualification of beneficiaries and utilization of health care services consumed by Jeju Island's residents for 1 year of period (from January to December 2000) and acquired their utilization features of cancer inpatient services. The independent variable was 10 different income levels according to the national health insurance fee imposed on each household in 2000. The dependent variable was the volume of cancer inpatient services utilized, that was measured by admission days and costs for treatment. The utilization of cancer inpatient services in the 10 different income groups was analyzed in three geographical categories of medical institutions: (1) within Jeju Island; (2) outside Jeju Island; (3) South Korea in total. We calculated the concentration-indices of cancer inpatient services utilization in admission days and cost as a pair amongst these three geographical categories each. Both of the concentration-indices were negative for the category of 'within Jeju Island', positive for that of 'outside Jeju Island', and positive for that of 'South Korea in total'. These results suggest the relatively poor experience considerable inequality in the utilization of cancer inpatient services in Jeju Island, because lower income groups have higher incidence rates in most cancers and inevitably have more needs in health services.

Unmet healthcare needs depending on employment status.

OBJECTIVES: The purpose of study is to find relevance between unmet healthcare needs and employment status and if factors have relevance to unmet healthcare needs due to "economic burden" and "no time to spare". METHODS: The study conducted a survey of 9163 respondents who said they needed a medical treatment or checkup were asked why the need for care was unmet. RESULTS: 22.9% of the respondents said they did not receive a medical treatment or checkup they needed at least once. The rate of unmet healthcare needs caused by "economic burden" was higher among temporary workers (ORs=2.13), day workers (ORs=1.92). However, the rate of unmet needs due to "no time to spare" was lower for temporary workers (ORs=.58) than for regular workers, studies (ORs=.33), housework (ORs=.26), early retirement (ORs=.19) and disease or injury (ORs=.07). CONCLUSION: Non-regular waged workers were more likely to have an unmet need for healthcare due to "economic burden" than regular waged workers. On the other hand, regular waged workers were less likely to receive necessary healthcare services due to "no time to spare" than non-regular waged workers and economically inactive people.

Nurse-perceived patient adverse events and nursing practice environment.

OBJECTIVES: To evaluate the occurrence of patient adverse events in Korean hospitals as perceived by nurses and examine the correlation between patient adverse events with the nurse practice environment at nurse and hospital level. METHODS: In total, 3096 nurses working in 60 general inpatient hospital units were included. A two-level logistic regression analysis was performed. RESULTS: At the hospital level, patient adverse events included patient falls (60.5%), nosocomial infections (51.7%), pressure sores (42.6%) and medication errors (33.3%). Among the hospital-level explanatory variables associated with the nursing practice environment, 'physician- nurse relationship' correlated with medication errors while 'education for improving quality of care' affected patient falls. CONCLUSIONS: The doctor-nurse relationship and access to education that can improve the quality of care at the hospital level may help decrease the occurrence of patient adverse events.

Influence of the nursing practice environment on job satisfaction and turnover intention.

OBJECTIVES: To examine whether the nursing practice environment at the hospital-level affects the job satisfaction and turnover intention of hospital nurses. METHODS: Among the 11 731 nurses who participated in the Korea Health and Medical Workers' Union's educational program, 5654 responded to our survey. Data from 3096 nurses working in 185 general inpatient wards at 60 hospitals were analyzed using multilevel logistic regression modeling. RESULTS: Having a standardized nursing process (odds ratio [OR], 4.21; p<0.001), adequate nurse staffing (OR, 4.21; p<0.01), and good doctor-nurse relationship (OR, 4.15; p<0.01), which are hospital-level variables based on the Korean General Inpatients Unit Nursing Work Index (KGU-NWI), were significantly related to nurses' job satisfaction. However, no hospital-level variable from the KGU-NWI was significantly related to nurses' turnover intention. CONCLUSIONS: Favorable nursing practice environments are associated with job satisfaction among nurses. In particular, having a standardized nursing process, adequate nurse staffing, and good doctor-nurse relationship were found to positively influence nurses' job satisfaction. However, the nursing practice environment was not related to nurses' turnover intention.

The incidence of stroke by socioeconomic status, age, sex, and stroke subtype: a nationwide study in Korea.

OBJECTIVES: To date, studies have not comprehensively demonstrated the relationship between stroke incidence and socioeconomic status. This study investigated stroke incidence by household income level in conjunction with age, sex, and stroke subtype in Korea. METHODS: Contributions by the head of household were used as the basis for income levels. Household income levels for 21 766 036 people were classified into 6 groups. The stroke incidences were calculated by household income level, both overall within income categories and further by age group, sex, and stroke subtype. To present the inequalities among the six ranked groups in a single value, the slope index of inequality and relative index of inequality were calculated. RESULTS: In 2005, 57 690 people were first-time stroke patients. The incidences of total stroke for males and females increased as the income level decreased. The incidences of stroke increased as the income level decreased in those 74 years old and under, whereas there was no difference by income levels in those 75 and over. Intracerebral hemorrhage for the males represented the highest inequality among stroke subtypes. Incidences of subarachnoid hemorrhage did not differ by income levels. CONCLUSIONS: The incidence of stroke increases as the income level decreases, but it differs according to sex, age, and stroke subtype. The difference in the relative incidence is large for male intracerebral hemorrhage, whereas the difference in the absolute incidence is large for male ischemic stroke.

Application of revised nursing work index to hospital nurses of South Korea.

PURPOSE: Based on the Revised Nursing Work Index (NWI-R), this research aimed to develop a Korean Hospital General Inpatient Unit-Nursing Work Index (KGU-NWI). This study also aimed to compare the common points and differences between the subfactors of the KGU-NWI and the subfactors from previous studies. METHODS: Based on opinions from 3,151 nurses in Korean hospital general inpatient unit, this research used 57 items of NWI-R and the principal axis factor analysis for deriving subfactors. We evaluated the convergent validity through factor analysis and the content validity of KGU-NWI in terms of the association between nurses' job outcome and the subfactors derived. RESULTS: Six subfactors and 26 items for KGU-NWI were derived from NWI-R. Among them, 'physician-nurse relationship', 'adequate nurse staffing' and 'organizational support and management of hospital' were the same with results from previous studies. In addition, two subfactors, 'participation of decision-making processes' and 'education for improving quality of care', which were similar with results from previous Korean studies, were newly added by using Korean hospital cases. In contrast to previous Korean studies, a unique subfactor this study found was 'nursing processes'. This research confirmed that the six subfactors were highly correlated with job satisfaction, intention to leave, and quality of health care, which represented a nurse's job outcome. CONCLUSION: KGU-NWI including six subfactors and 26 items is an applicable instrument to investigate nurse work environment in Korean hospital general inpatient unit.

Determinants of public satisfaction with the National Health Insurance in South Korea.

To explore the determinants of public satisfaction with the National Health Insurance, this study re-analyzed the 2004 public satisfaction survey with the Korean National Health Insurance (KNHI) conducted by Korean National Health Insurance Corporation (KNHIC). One thousand samples were selected with probability proportional to population size (by region/sex/age). The data collected by home-visit interview were transformed into the final data set by matching them to the insured's benefit database and the qualification database. The results showed that metropolitan residence, insured type, relationship between respondent and householder, subjective health status, benefit-cost ratio, and attitudes toward KNHI were direct determinants of satisfaction with KNHI. In addition, various demographic and socioeconomic variables and the health status of the respondent's family indirectly influenced satisfaction with KNHI. Among these variables, the attitude toward KNHI was the most vital factor to determine public satisfaction. The study results show that equity in monthly contributions and an enhanced quantity and quality of medical services are required to improve public satisfaction with KNHI. Furthermore, it is important to improve the public perception of social values and solidarity for increased public satisfaction with KNHI.