Effect of the human papillomavirus vaccine on the risk of genital warts: a nationwide cohort study of Korean adolescent girls.

OBJECTIVES: The purpose of this study was to assess the effectiveness of human papillomavirus (HPV) vaccination administered to adolescent girls through Korea's National Immunization Program. METHODS: This retrospective cohort study included patients who were 12-13 years old, whether vaccinated or unvaccinated, between July 2016 and December 2017. The incidence of genital warts (GWs) was monitored through 2021. Time-stratified hazard ratios (HRs) were estimated, adjusting for birth year, socioeconomic status, and the level of urbanization of the region, and were presented with 95% confidence intervals (CIs). Data were sourced from the Immunization Registry Integration System, linked with the National Health Information Database. RESULTS: The study included 332,062 adolescent girls, with an average follow-up period of approximately 4.6 years. Except for the first year, the HRs for the vaccinated group were lower than those for the unvaccinated group. The HRs for specific cut-off years were as follows: year 2, 0.62 (95% CI, 0.31 to 1.13); year 3, 0.58 (95% CI, 0.35 to 0.96); and year 4 and beyond, 0.39 (95% CI, 0.28 to 0.52). CONCLUSIONS: Our findings indicate that HPV vaccination was associated with a reduction in the risk of GWs among adolescent girls. Notably, this reduction became significant as the incidence of GWs increased with age.

Factors affecting the survival of early COVID-19 patients in South Korea: An observational study based on the Korean National Health Insurance big data.

OBJECTIVES: This study aimed to identify the survival rate and explore factors affecting survival among early COVID-19 patients in South Korea. METHODS: Data reported by the Korea Disease Control and Prevention Agency (KDCA), up to 15 July, when COVID-19 was confirmed were used as research data in connection with the National Health Insurance Service's (NHIS) national health information database. The final analysis targets were 12,646 confirmed patients and 303 deaths. The survival rate of patients with COVID-19 was estimated through Kaplan-Meier survival analysis. Cox proportional hazard regression analysis was performed to search for factors affecting survival. RESULTS: When looking at the survival rate by age group for men and women, the 28-day survival rate for men aged >80 years was 77% and 73% at 42 days, while 83% and 81% for women. Men had a worse survival rate than women. For chronic diseases, the highest risk of mortality was observed in malignant neoplasms of the respiratory and urogenital systems, followed by diseases of the urinary system and diabetes. CONCLUSIONS: The number of COVID-19 deaths was highest the next day after initial diagnosis. The case fatality rate was high in males, older age, and chronic diseases.

Factors Affecting the Incidence of Hospitalized Pneumonia after Influenza Infection in Korea Using the National Health Insurance Research Database, 2014-2018: Focusing on the Effect of Antiviral Therapy in the 2017 Flu Season.

BACKGROUND: This study aimed to investigate the effect of antiviral therapy following influenza outpatient episodes on the incidence of hospitalized pneumonia episodes, one of secondary complications of influenza. METHODS: In the National Health Insurance Research Database, data from July 2013 to June 2018 were used. All of the claim data with diagnoses of influenza and pneumonia were converted to episodes of care after applying 100 days of window period. With the 100-day episodes of care, the characteristics of influenza outpatient episodes and antiviral therapy for influenza, the incidence of hospitalized pneumonia episodes following influenza, and the effect of antiviral therapy for influenza on hospitalized pneumonia episodes were investigated. RESULTS: The crude incidence rate of hospitalized pneumonia after influenza infection was 0.57% in both males and females. Factors affecting hospitalized pneumonia included age, income level except self-employed highest (only in females), municipality, medical institution type, precedent chronic diseases except hepatitis (only in females) and antiviral therapy. In the 2017 flu season, the relative risk was 0.38 (95% confidence interval [CI], 0.29-0.50) in males aged 0-9 and 0.43 (95% CI, 0.32-0.57) in females aged 0-9 without chronic diseases, and it was 0.51 (95% CI, 0.42-0.61) in males aged 0-9 and 0.42 (95% CI, 0.35-0.50) in females aged 0-9 with one or more chronic diseases in the aspect of the effect of antiviral therapy on pneumonia. It suggests that antiviral therapy may decrease the incidence of pneumonia after influenza infection. CONCLUSION: After outpatient episode incidence of influenza, antiviral treatment has been shown to reduce the incidence of hospitalized pneumonia, especially in infants and children, during pandemic season 2017. Antiviral therapy for influenza is recommended to minimize burden caused by influenza virus infection and to reduce pneumonia. In addition, medical costs of hospitalization may decrease by antiviral therapy, especially in infants and children.

The Correlation of Comorbidities on the Mortality in Patients with COVID-19: an Observational Study Based on the Korean National Health Insurance Big Data.

BACKGROUND: Mortality of coronavirus disease 2019 (COVID-19) is a major concern for quarantine departments in all countries. This is because the mortality of infectious diseases determines the basic policy stance of measures to prevent infectious diseases. Early screening of high-risk groups and taking action are the basics of disease management. This study examined the correlation of comorbidities on the mortality of patients with COVID-19. METHODS: We constructed epidemiologic characteristics and medical history database based on the Korean National Health Insurance Service Big Data and linked COVID-19 registry data of Korea Centers for Disease Control & Prevention (KCDC) for this emergent observational cohort study. A total of 9,148 patients with confirmed COVID-19 were included. Mortalities by sex, age, district, income level and all range of comorbidities classified by International Classification of Diseases-10 based 298 categories were estimated. RESULTS: There were 3,556 male confirmed cases, 67 deaths, and crude death rate (CDR) of 1.88%. There were 5,592 females, 63 deaths, and CDR of 1.13%. The most confirmed cases were 1,352 patients between the ages of 20 to 24, followed by 25 to 29. As a result of multivariate logistic regression analysis that adjusted epidemiologic factors to view the risk of death, the odds ratio of death would be hemorrhagic conditions and other diseases of blood and blood-forming organs 3.88-fold (95% confidence interval [CI], 1.52-9.88), heart failure 3.17-fold (95% CI, 1.88-5.34), renal failure 3.07-fold (95% CI, 1.43-6.61), prostate malignant neoplasm 2.88-fold (95% CI, 1.01-8.22), acute myocardial infarction 2.38-fold (95% CI, 1.03-5.49), diabetes was 1.82-fold (95% CI, 1.25-2.67), and other ischemic heart disease 1.71-fold (95% CI, 1.09-2.66). CONCLUSION: We hope that this study could provide information on high risk groups for preemptive interventions. In the future, if a vaccine for COVID-19 is developed, it is expected that this study will be the basic data for recommending immunization by selecting those with chronic disease that had high risk of death, as recommended target diseases for vaccination.

Compliance of Antihypertensive Medication and Risk of Coronavirus Disease 2019: a Cohort Study Using Big Data from the Korean National Health Insurance Service.

BACKGROUND: There is a controversy whether it is safe to continue renin-angiotensin system blockers in patients with coronavirus disease 2019 (COVID-19). We analyzed big data to investigate whether angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blockers have any significant effect on the risk of COVID-19. Population-based cohort study was conducted based on the prescription data from nationwide health insurance records. METHODS: We investigated the 1,374,381 residents aged ≥ 40 years living in Daegu, the epicenter of the COVID-19 outbreak, between February and March 2020. Prescriptions of antihypertensive medication during the year before the outbreak were extracted from the National Health Insurance Service registry. Medications were categorized by types and stratified by the medication possession ratios (MPRs) of antihypertensive medications after controlling for the potential confounders. The risk of COVID-19 was estimated using a difference in difference analysis. RESULTS: Females, older individuals, low-income earners, and recently hospitalized patients had a higher risk of infection. Patients with higher MPRs of antihypertensive medications had a consistently lower risk of COVID-19 than those with lower MPRs of antihypertensive medications and non-users. Among patients who showed complete compliance, there was a significantly lower risk of COVID-19 for those prescribed angiotensin II receptor blockers (relative risk [RR], 0.751; 95% confidence interval [CI], 0.587-0.960) or calcium channel blockers (RR, 0.768; 95% CI, 0.601-0.980). CONCLUSION: Renin-angiotensin system blockers or other antihypertensive medications do not increase the risk of COVID-19. Patients should not stop antihypertensive medications, including renin-angiotensin system blockers, because of concerns of COVID-19.

Age-Period-Cohort Analysis of Influenza in Koreans: the National Health Insurance Research Database, 2009-2018.

BACKGROUND: This study aimed to identify the incidence rate of episodes diagnosed with influenza and the effects of age-period-cohort (APC) in Koreans. METHODS: The 2009-2018 National Health Insurance Research Database was used for analysis. All time-related claims connected relatively short window period in 100 days. The case definition was defined by all codes diagnosed with J09, J10, and J11. Calculation of the incidence rate and APC analysis adjusted income levels by insurance type, metropolitan city was performed to identify the characteristics of episodes diagnosed with influenza. RESULTS: Incidence rate by age and cohort gradually increased since 2014. The incidence rate of males aged 0-4 years was 171.02 and that of females was 173.31 in 2015-2016 season. In males, 29.19 in 1963 cohort and 243.79 in 2013 cohort were confirmed as high incidence rates in 2017-2018 season. In the females, a high incidence was confirmed in 1953-1967 cohort and 1978-1987 cohort, and the incidence was 251.38 in 2013-2017 cohort. APC effects showed a high relative risk in the infants, the pandemic influenza season in 2010 (1/7/2009 to 30/6/2010) and the adults of 1978-1987 cohort. CONCLUSION: Since 2014, influenza outbreaks have been increasing every year. The start year of free vaccination decreased the incidence in infants and adults over 65 years of age but the incidence increased from the following year. Because influenza can be primarily prevented by vaccination, reinforcement of vaccination in infants may reduce the disease burden in their parents, and also the risk of infection caused by family transmission. A new vaccination strategy is needed to reduce the incidence and burden of diseases caused by influenza infection.

Family-based case-control study of exposure to household humidifier disinfectants and risk of idiopathic interstitial pneumonia.

BACKGROUND: In Korea, several household humidifier disinfectants (HDs) were clinically confirmed to cause HD-associated lung injury (HDLI). Polyhexamethylene guanidine (PHMG) phosphate is the main ingredient of the HDs found to be associated with lung disease. However, the association of HDs with other interstitial lung disease including idiopathic interstitial pneumonia (IIP) is not clear. We examined the relationship between HD exposure and IIP in a family-based study. METHODS: This case-control study included 244 IIP cases and 244 family controls who lived with the IIP patients. The IIP cases were divided into two groups, HDLI and other IIP, and were matched to family controls based on age and gender. Information on exposure to HDs was obtained from a structured questionnaire and field investigations. Conditional logistic regression was used to estimate odds ratio (ORs) and their corresponding 95% confidence interval (CI), investigating the association of HD-related exposure characteristics with IIP risk. RESULTS: The risks of IIP increased two-fold or more in the highest compared with the lowest quartile of several HD use characteristics, including average total use hours per day, cumulative sleep hours, use of HD during sleep, and cumulative exposure level. In analyses separated by HDLI and other IIP, the risks of HDLI were associated with airborne HD concentrations (adjusted OR = 3.01, 95% CI = 1.34-6.76; Q4 versus Q1) and cumulative exposure level (adjusted OR = 3.57, 95% CI = 1.59-8.01; Q4 versus Q1), but this relationship was not significant in the patients with other IIP. In comparison between HDLI and other IIP, the odds ratios of average total use hours, cumulative use hours, and cumulative sleeps hours was higher for other IIP. CONCLUSION: The use of household HDs is associated not only with HDLI but also with other IIP.

The coverage rates for influenza vaccination and related factors in Korean adults aged 50 and older with chronic disease: based on 2016 Community Health Survey data.

OBJECTIVES: This study aims to identify the coverage rates for influenza vaccination and related factors depending on chronic disease in Korean adults aged 50 and older. METHODS: The 2016 Korea Community Health Survey was used for analysis. Chi-square test was performed to investigate the coverage rates for influenza vaccination depending on chronic disease, and a multiple logistic regression analysis was used to identify the factors associated with influenza vaccination, by chronic disease. RESULTS: In men with ≥1 chronic disease, 39.8% of 50-64 years of age, and 86.8% of elderly (over 65 years of age) received influenza vaccination. In women with ≥1 chronic disease, 58.7% of 50-64 years of age, and 89.9% of elderly (over 65 years of age) received influenza vaccination (p<0.001). The chronic diseases associated with influenza vaccination were hypertension (odds ratio [OR], 1.27; 95% confidence interval [CI], 1.19 to 1.37), diabetes (OR, 1.41; 95% CI, 1.28 to 1.55) in men aged 50-64, hypertension (OR, 1.34; 95% CI, 1.20 to 1.49), diabetes (OR, 1.17; 95% CI, 1.02 to 1.33), chronic cardiovascular disease (OR, 1.31; 95% CI, 1.07 to 1.60) in elderly (over 65 years of age). In women aged 50-64, hypertension (OR, 1.39; 95% CI, 1.30 to 1.49), diabetes (OR, 1.51; 95% CI, 1.35 to 1.68), chronic cardiovascular disease (OR, 1.31; 95% CI, 1.05 to 1.64), and hypertension (OR, 1.55; 95% CI, 1.40 to 1.71), diabetes (OR, 1.27; 95% CI, 1.12 to 1.43) in elderly (over 65 years of age). CONCLUSIONS: Populations in aged 50-64 are recommendation subject for vaccination or classified as high-risk group in case with chronic disease. Though subject over 60 years old is age close to the elderly, the coverage rates for vaccination was low. It is necessary to devise strategies to raise the coverage rates for vaccination.

Older adults' perception of chronic illness management in South Korea.

OBJECTIVES: Despite the recent emphasis on a patient-centered chronic care model, few studies have investigated its use in older adults in South Korea. We explored how older Korean adults perceive and cope with their chronic illness. METHODS: We conducted focus group interviews in Seoul, Korea in January 2010. Focus groups were formed by disease type (hypertension and type 2 diabetes) and gender using purposive sampling. Inclusion criteria were patients aged 60 and over who had been diagnosed with diabetes or hypertension and received care at a community health center for at least six months prior to participation. Interview data were analyzed through descriptive content analysis. RESULTS: Among personal factors, most participants felt overwhelmed when they received their diagnosis. However, with time and control of their acute symptoms using medication, their worry diminished and participants tended to denying being identified as a patient or sick person. Among socio-familial factors, participants reported experiencing stigma with their chronic illness and feeling it was a symbol of weakness. Instead of modifying their lifestyles, which might interfere with their social relationships, they resorted to only following their medicine regime prescribed by their doctor. Participants also reported feeling that their doctor only prescribed medications and acted in an authoritative and threatening manner to induce and reinforce participants' compliance with treatment. CONCLUSIONS: For successful patient-centered management of chronic illnesses, supportive environments that include family, friends, and healthcare providers should be established. OBJECTIVES: Despite the recent emphasis on a patient-centered chronic care model, few studies have investigated its use in older adults in South Korea. We explored how older Korean adults perceive and cope with their chronic illness. METHODS: We conducted focus group interviews in Seoul, Korea in January 2010. Focus groups were formed by disease type (hypertension and type 2 diabetes) and gender using purposive sampling. Inclusion criteria were patients aged 60 and over who had been diagnosed with diabetes or hypertension and received care at a community health center for at least six months prior to participation. Interview data were analyzed through descriptive content analysis. RESULTS: Among personal factors, most participants felt overwhelmed when they received their diagnosis. However, with time and control of their acute symptoms using medication, their worry diminished and participants tended to denying being identified as a patient or sick person. Among socio-familial factors, participants reported experiencing stigma with their chronic illness and feeling it was a symbol of weakness. Instead of modifying their lifestyles, which might interfere with their social relationships, they resorted to only following their medicine regime prescribed by their doctor. Participants also reported feeling that their doctor only prescribed medications and acted in an authoritative and threatening manner to induce and reinforce participants' compliance with treatment. CONCLUSIONS: For successful patient-centered management of chronic illnesses, supportive environments that include family, friends, and healthcare providers should be established.

Diabetes epidemics in Korea: reappraise nationwide survey of diabetes "diabetes in Korea 2007".

There are many studies on the prevalence, clinical characteristics, and economic burden of diabetes across the past four decades in Korea. Nonetheless, there is a dearth of nationwide study regarding diabetes encompassing all age group. Eight years ago, the Committee on the Epidemiology of Diabetes Mellitus of Korean Diabetes Association collaborated with Health Insurance Review & Assessment Service to evaluate the status of diabetes care and characteristics in diabetic patients in Korea. In 2007, the collaborative task force team published a comprehensive survey titled "Diabetes in Korea 2007." In this review, we reappraise the diabetic epidemics from the joint report and suggest further studies that are needed to be investigated in the future.

Burden of ischemic stroke in Korea: analysis of disability-adjusted life years lost.

BACKGROUND AND PURPOSE: Disability-adjusted life years (DALY), incorporating both disability and mortality, has been widely employed to measure regional and global burdens of stroke. Thus far, the DALY lost to stroke in a population has been estimated using only the crude population-level data; no previous study has incorporated refined data from stroke registries. The aim of this study was to integrate the stroke registry data and the population-level incidence data to project the nationwide DALY lost to ischemic stroke. METHODS: from the data of two large ischemic stroke registries, we derived an average daly lost due to ischemic stroke for each of the following age groups: <45, 45-54, 55-64, 65-74, 75-84, and ≥85 years. The nationwide ischemic stroke incidence for each age group was extracted from a cardiovascular and cerebrovascular surveillance study that analyzed the 2004 Korean Health Insurance database. RESULTS: The average DALY lost due to ischemic stroke for the age groups <45, 45-54, 55-64, 65-74, 75-84, and ≥85 years was 5.07, 4.63, 4.35, 3.88, 2.88, and 1.73, respectively. By multiplying the incidence and the average DALY lost, the nationwide DALY lost was determined to be 9,952 for those <45 years, 24,608 for 45-54 years, 50,682 for 55-64 years, 88,875 for 65-74 years, 52,089 for 75-84 years, and 8,192 for ≥85 years, respectively. The projected nationwide DALY lost due to 64,688 ischemic strokes in 2004 was 234,399 (121,482 for men and 113,244 for women), and the DALY lost per 100,000 person-years was 483 (500 for men and 469 for women). CONCLUSIONS: Incidence data from a population study and DALY values derived from stroke registries can be integrated to provide a more refined projection of the nationwide burden of ischemic stroke. In Korea, more than 230,000 years of healthy life are being lost annually due to ischemic stroke, and hence prompt action is imperative.

Continuity of care for elderly patients with diabetes mellitus, hypertension, asthma, and chronic obstructive pulmonary disease in Korea.

We sought to assess continuity of care for elderly patients in Korea and to examine any association between continuity of care and health outcomes (hospitalization, emergency department visits, health care costs). This was a retrospective cohort study using the Korea National Health Insurance Claims Database. Elderly people, 65-84 yr of age, who were first diagnosed with diabetes mellitus (n=268,220), hypertension (n=858,927), asthma (n=129,550), or chronic obstructive pulmonary disease (COPD, n=131,512) in 2002 were followed up for four years, until 2006. The mean of the Continuity of Care Index was 0.735 for hypertension, 0.709 for diabetes mellitus, 0.700 for COPD, and 0.663 for asthma. As continuity of care increased, in all four diseases, the risks of hospitalization and emergency department visits decreased, as did health care costs. In the Korean health care system, elderly patients with greater continuity of care with health care providers had lower risks of hospital and emergency department use and lower health care costs. In conclusion, policy makers need to develop and try actively the program to improve the continuity of care in elderly patients with chronic diseases.

Long-term trend in the incidence of acute myocardial infarction in Korea: 1997-2007.

BACKGROUND AND OBJECTIVES: Information about disease incidence is indispensable for the active prevention and control of acute myocardial infarction (AMI). The purpose of this study was to provide basic information for the establishment of policy related to AMI by examining the long-term trends in incidence of AMI. SUBJECTS AND METHODS: This study identified the trend in disease incidence during between 1997 and 2007 using the Korean National Health Insurance Database that includes AMI {the 10th International Classification of Disease (ICD-10) code: I21, I22, I23, I250, I251} as a primary or secondary disease. RESULTS: The attack and incidence rates for AMI in 2007 were 118.4 and 91.8 per 100,000 persons, respectively, and the rates more than doubled for the 11 years. Both rates were higher among males than females and increased more in the older age groups. Incidence cases accounted for most of the total attack cases every year; however, in recent years the proportion of relapse cases was on the rise. The case fatality rate was highest (14.5%) in 2000, and declined rapidly to 9.8% in 2007. The case fatality rate was higher among females than males and the older age groups; in particular, female patients >/=65 years of age had the highest fatality rate. CONCLUSION: This study showed that AMI has been on the rise in Korea for 11 years. Therefore, the establishment of policy for intensive control of the incidence of AMI is necessary by building a continuous monitoring and surveillance system.

Development and validation of the Excess Mortality Ratio-adjusted Injury Severity Score Using the International Classification of Diseases 10th Edition.

OBJECTIVES: This study aimed to develop and validate a new method for measuring injury severity, the excess mortality ratio-adjusted Injury Severity Score (EMR-ISS), using the International Classification of Diseases 10th Edition (ICD-10). METHODS: An injury severity grade similar to the Abbreviated Injury Scale (AIS) was converted from the ICD-10 codes on the basis of quintiles of the EMR for each ICD-10 code. Like the New Injury Severity Score (NISS), the EMR-ISS was calculated from three maximum severity grades using data from the Korean National Injury Database. The EMR-ISS was then validated using the Hosmer-Lemeshow goodness-of-fit chi-square (HL chi-square, with lower values preferable), the area under the receiver operating characteristic curve (AUC-ROC), and the Pearson correlation coefficient to compare it with the International Classification of Diseases 9th Edition-based Injury Severity Score (ICISS). Nationwide hospital discharge abstract data (DAD) from stratified-sample general hospitals (n = 150) in 2004 were used for an external validation. RESULTS: The total number of study subjects was 29,282,531, with five subgroups of particular interest identified for further study: traumatic brain injury (TBI, n = 3,768,670), traumatic chest injury (TCI,n = 1,169,828), poisoning (n = 251,565), burns (n = 869,020), and DAD (n = 26,374). The HL chi-square was lower for EMR-ISS than for ICISS in all groups: 42,410.8 versus 55,721.9 in total injury, 7,139.6 versus 20,653.9 in TBI, 6,603.3 versus 4,531.8 in TCI, 2,741.2 versus 9,112.0 in poisoning, 764.4 versus 4,532.1 in burns, and 28.1 versus 49.4 in DAD. The AUC-ROC for death was greater for EMR-ISS than for ICISS: 0.920 versus 0.728 in total injury, 0.907 versus 0.898 in TBI, 0.675 versus 0.799 in TCI, 0.857 versus 0.900 in poisoning, 0.735 versus 0.682 in burns, and 0.850 versus 0.876 in DAD. The Pearson correlation coefficient between the two scores was )0.68 in total injury, )0.76 in TBI, )0.86 in TCI, )0.69 in poisoning,)0.58 in burns, and )0.75 in DAD. CONCLUSIONS: The EMR-ISS showed better calibration and discrimination power for prediction of death than the ICISS in most injury groups. The EMR-ISS appears to be a feasible tool for passive injury surveillance of large data sets, such as insurance data sets or community injury registries containing diagnosis codes. Additional further studies for external validation on prospectively collected data sets should be considered.

[An evaluation of sampling design for estimating an epidemiologic volume of diabetes and for assessing present status of its control in Korea].

OBJECTIVES: An appropriate sampling strategy for estimating an epidemiologic volume of diabetes has been evaluated through a simulation. METHODS: We analyzed about 250 million medical insurance claims data submitted to the Health Insurance Review & Assessment Service with diabetes as principal or subsequent diagnoses, more than or equal to once per year, in 2003. The database was re-constructed to a 'patient-hospital profile' that had 3,676,164 cases, and then to a 'patient profile' that consisted of 2,412,082 observations. The patient profile data was then used to test the validity of a proposed sampling frame and methods of sampling to develop diabetic-related epidemiologic indices. RESULTS: Simulation study showed that a use of a stratified two-stage cluster sampling design with a total sample size of 4,000 will provide an estimate of 57.04% (95% prediction range, 49.83 - 64.24%) for a treatment prescription rate of diabetes. The proposed sampling design consists, at first, stratifying the area of the nation into "metropolitan/city/county" and the types of hospital into "tertiary/secondary/primary/clinic" with a proportion of 5:10:10:75. Hospitals were then randomly selected within the strata as a primary sampling unit, followed by a random selection of patients within the hospitals as a secondly sampling unit. The difference between the estimate and the parameter value was projected to be less than 0.3%. CONCLUSIONS: The sampling scheme proposed will be applied to a subsequent nationwide field survey not only for estimating the epidemiologic volume of diabetes but also for assessing the present status of nationwide diabetes control.

Development of the Korean primary care assessment tool--measuring user experience: tests of data quality and measurement performance.

OBJECTIVE: To develop a tool for assessing the performance of primary care services in South Korea from the patient's perspective and to test the validity of the tool under the conceptual framework of the recently developed definition of primary care in Korea. DESIGN: Item development for questionnaire and a cross-sectional survey for tool validation at 16 primary care clinics. All family physicians included in this study were required to have practiced at their current clinic for at least 2 years. PARTICIPANTS: A nine expert panel was assembled for tool development and patients (or guardians) who had visited their primary care clinic on six or more occasions over a period of more than 6 months participated in the survey. MAIN OUTCOME MEASURES: Scores corresponding to each domain of primary care. RESULTS: A total of 722 effective data sets were used for the analysis. Five items were eliminated from the preliminary 30-item tool after expert discussions at two seminars. Another four items were eliminated by principle component analysis. For each of the four domains (comprehensiveness, coordination function, personalized care, and family/community orientation), tests of scaling assumptions were well satisfied by all Likert-scaled measures. On the other hand, 'first contact' turned out to be a composite domain with five independent single-item scales. CONCLUSION: The Korean primary care assessment tool (version 1) consists of four multi-item scales and one composite scale. Widespread application of this tool will provide an empirical basis for the measurement, monitoring and continuous improvement of primary care in South Korea.

Association between socioeconomic status and burn injury severity.

BACKGROUND: It has been previously established that the incidence of burn is higher in lower socioeconomic (SES) groups. What is not clear, however, is whether or not the severity of burn is also higher in lower SES groups. The purpose of this study is to establish a relationship between household-level socioeconomic status (SES) and severity-based incidence of burn. METHODS: A burn injury database was generated from the National Injury Database (2001-2003) with a 1-year follow-up period containing information about the date and time of burn injury, the International Classification of Disease 10th Edition-based (ICD-10) diagnostic codes, gender, age, residence, and type of insurance. In addition, we calculated the severity of each burn using the Excess Mortality Ratio-adjusted Injury Severity Score (EMR-ISS), which is similar to the New Injury Severity Score. Socioeconomic status was measured on the basis of quintiles of premiums for National Health Insurance, which was decided on a household-level either by monthly salary (Employee Insurance, EI) or by owned property (Self-Employed Insurance, SEI). Medical Aid (MA) population was regarded as a reference. After calculation of 5 year-gender specific standardized incidence rates (SIRs) of burn by SES groups, the association of SES and severity of burn was evaluated using a multivariate logistic regression model and the Cox-proportional hazard regression analysis. RESULTS: A total of 870,411 burn cases were examined. The standardized incident rates (SIRs) of mild(1

[The socioeconomic cost of injuries in South Korea].

OBJECTIVES: This study was conducted to estimate the socioeconomic cost of injuries in South Korea. METHODS: We matched claims data from national health insurance, automobile insurance and industrial accident compensation insurance (IACI), and mortality data obtained from the national statistical office from 2001 to 2003 by patients' unique identifier. Socioeconomic cost included both direct cost and indirect cost: the direct cost was injury-related medical expenditure and the indirect cost included loss of productivity due to healthcare utilization and premature death. RESULTS: The socioeconomic cost of injuries in Korea was approximately 1.9% of the GDP from 2001 to 2003. That is, 12.1 trillion KRW (Korean Won) in 2001, 12.3 trillion KRW in 2002, and 13.7 trillion KRW in 2003. In 2003, direct medical costs were 24.6% (3.4 trillion KRW), the costs for loss of productivity by healthcare utilization were 13.0% (1.8 trillion KRW), and the costs for loss of productivity by premature death were 62.4% (8.6 trillion KRW). CONCLUSIONS: In this study, the socioeconomic cost of injuries in Korea between 2001 and 2003 was estimated by using not only health insurance claims data, but also automobile insurance, IACI claims and mortality data. We conclude that social efforts are required to reduce the socioeconomic cost of injuries in Korea, which represented approximately 1.9% of the GDP for the time period specified.

Nurse staffing and patient mortality in intensive care units.

BACKGROUND: Research evidence suggests that nurse staffing influences patient outcomes. OBJECTIVES: To examine the relationship between nurse staffing and patient mortality in Korean intensive care units (ICUs). METHODS: Using survey and administrative databases, this study included 27,372 ICU patients discharged from 42 tertiary and 194 secondary hospitals. Ownership (public vs. private), location (metropolitan city vs. province), size, specialization of ICUs (specialized vs. mixed), physician staffing and nurse staffing, and years of nurse experience were included as hospital and ICU characteristics. Nurse staffing was measured as the ratio of average daily census to the total number of full-time equivalent registered nurses in ICUs. Age, gender, 26 categories of primary diagnoses, 16 groups of comorbid conditions, and source of payment were used for risk adjustment. Mortality was defined as deaths that occurred in the hospital or on the date of hospital discharge. Using SAS GLIMMIX procedures, multivariate logistic regression analysis was employed separately for tertiary and secondary hospitals. RESULTS: In tertiary hospitals, a greater likelihood of dying was found among patients who were admitted to a mixed ICU (odds ratio [OR] = 1.61, 95% confidence interval [CI] = 1.14-2.26) and where there was no board-certified physician present for 4 or more hours per day (OR = 1.56, 95% CI = 1.20-2.01). In secondary hospitals, every additional patient per RN was associated with a 9% increase in the odds of dying (OR = 1.09, 95% CI = 1.04-1.14). Nurse experience had no significant relationship with mortality. DISCUSSION: Nurse and physician staffing and specialization of ICUs impacted patient mortality. Associations differed in tertiary and secondary hospitals. Further investigation of the impact of organizational environments in ICUs is needed.

The weather watch/warning system for stroke and asthma in South Korea.

Weather watch/warning systems have been established for human health outcomes. Our study aims to develop and demonstrate a weather watch/warning system for asthma and stroke within the whole of South Korea, using a stratified regression approach. We converted claim-based health insurance data covering almost all medical claims for the only health insurance system in Korea for asthma and stroke from 1996-2003 into personalized disease episode data, and combined them with meteorological data. We utilized a step-wise regression method using factors extracted from the meteorological data to develop stratified models for six (stroke) and nine (asthma) regional and day-of-week strata. Validation studies showed that the actual number of hospitalizations in 2003 increased according to the three-leveled predictions (levels I, II, and III) from the model based on the 1996-2002 data. This system is accessible via the internet (http://industry.kma.go.kr/APP/sub_APP15_H01.htm) at the Korean Meteorological Administration website.