- A Study on the Seropositivity of HBsAg among Biennial Health Examinees: A Nation-wide Multicenter Survey.
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Dae Sung Kim, Young Sik Kim, Jae Yong Kim, Yoon Ok Ahn
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Korean J Prev Med. 2002;35(2):129-135.
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Abstract
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- OBJECTIVE
The primary objective of this study was to estimate the prevalence of HBsAg-positives in the late 1990's among Korean adults. In addition, we evaluated the association of age, a residential area, a vaccination rate, a family history of chronic liver diseases and a past history of acute liver disease with the seropositivity of HBsAg, and estimated the prevalence of chronic HBV infection by follow-up for 6 month or more. METHODS: A total of 10 areas, six metropolitan and four small cities, were selected. In each cities, one health screening center was selected for recruitment of study subjects. The study subjects were enrolled from a general health examination program that is provided by medical insurance companies. Questionnaires on various risk factors were administered to the study subjects. Sera was drawn and tested for HBsAg by radioimmunoassay. HBeAg and ALT were also tested for those of HBsAg positive. The HBsAg positives was retest for HBsAg 6 months later. RESULTS: Among the study subjects (n= 1816), the seroprevalence of HBsAg was 5.5% (95% CI= 4.5%-6.6%), 7.4% in men (95% CI= 5.8-9.4) and 3.6% in women (95% CI= 2.5-5.0). A past history of acute liver disease and a family history of chronic liver diseases was shown to be risk factors for HBsAg positivity. Among the 31 HBsAg-positives, negative seroconversion rate was estimated to be 3.2 %, Thus, prevalence of chronic HBV infection was estimated to be 5.3% (95% CI= 3.7-6.6). CONCLUSION: In this study, the HBsAg seroprevalence rate was lower than that of the other studies in 1980's, particularly in young adult and women. Considering the public health importance of liver cancer and chronic liver diseases, the further effort is needed to prevent and reduce the HBV infection.
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Summary
- Incidence and Risk Factors for Diabetes Mellitus in Korean Middle-aged Men: Seoul Cohort DM Follow-up Study.
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Dong Hyun Kim, Yoon Ok Ahn, Sung Woo Park, Moon Gi Choi, Dae Sung Kim, Moo Song Lee, Myung Hee Shin, Jong Myon Bae
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Korean J Prev Med. 1999;32(4):526-537.
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Abstract
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- OBJECTIVES
It is known that the prevalence of diabetes mellitus(DM) appears to be rapidly increasing in recent times in Korea, presumably due to a westernized diet and change of life style followed by rapid economic growth. Based on the Seoul male cohort which was constructed in 1993, this study was conducted to estimate the annual incidence rates of DM through 4 years' follow up and to determine which factors are associated with DM risk in Korean middle-aged men. METHODS: Among 14,533 men recruited at baseline, 559 were excluded because they reported a history of diabetes or were found to be diabetes at 1992 routine health examination. During 4 years follow-up, 237 incident DM cases were ascertained through chart reviews and telephone contacts for those who have ever visited hospitals or clinics under suspicion of DM during 1993-1996 and the biennial routine health examinations in 1994 and 1996. RESULTS: In this study the annual incidence of DM among the study population was estimated to be 0.5 per 100. This study showed that fasting glucose level at initial baseline examination was a powerful predictor of risk for diabetes several years later(fasting blood glucose of > or = 110 mg/dl compared with < or = 80 mg/dl, Hazard Ratio[HR]=15.6, 95% Confidence interval[CI]=9.1-26.6) after considering potential covariates such as age, family history, smoking and alcohol history, body mass index, physical activity, total energy intake, and total fiber intake. Adjusted hazard ratios of family history of diabetes was 1.95(95% CI=1.38-2.75); of obesity as measured by BMI(BMI > or = 25.3 compared with < or = 21.3) was 7.19(95% CI=3.75-13.8); of weight change during middle life(>10kg compared with 5) was 1.77(95% CI=1.16-2.69); of smoking(current vs none) was 1.93(95% CI=1.06-3.51); and fat intake(upper tertile compared with lower tertile) was 1.88(95% CI=1.01-3.49), while fiber intake was associated with the reduced risk(HR=0.36, 95% CI=0.19-0.67). CONCLUSION: The factors identified in this study indicate that the greatest reduction in risk of diabetes might be achieved through population-based efforts that promote fiber intake and reduce obesity, smoking, and fat intake.
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Summary
- A Cohort Study on Risk Factors for Chronic Liver Disease: Analytic Strategies Excluding Potentially Incident Subjects.
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Moo Song Lee, Dae Sung Kim, Dong Hyun Kim, Jong Myun Bae, Myung Hee Shin, Yoon Ok Ahn
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Korean J Prev Med. 1999;32(4):452-458.
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Abstract
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- OBJECTIVES
The authors conducted the study to evaluate bias when potentially diseased subjects were included in cohort members while analyzing risk factors of chronic liver diseases. METHODS: Total of 14,529 subjects were followed up for the incidence of liver diseases from January 1993 to June 1997. We have used databases of insurance company with medical records, cancer registry, and death certificate data to identify 102 incident cases. The cohort members were classified into potentially diseased group(n=2,217) when they were HBsAg positive, serum GPT levels higher than 40 units, or had or has liver diseases in baseline surveys. Cox' model were used for potentially diseased group, other members, and total subjects, respectively. RESULTS: The risk factors profiles were similar for total and potentially diseased subjects: HBsAg positivity, history of acute liver disease, and recent quittance of smoking or drinking increased the risk, while intake of pork and coffee decreased it. For the potentially diseased, obesity showed marginally significant protective effect. Analysis of subjects excluding the potentially diseased showed distinct profiles: obesity increased the risk, while quitting smoking or drinking had no association. For these intake of raw liver or processed fish or soybean paste stew increased risk; HBsAg positivity, higher levels of liver enzymes and history of acute liver diseases increased the risk. CONCLUSIONS: The results suggested the potential bias in risk ratio estimates when potentially diseased subjects were included in cohort study on chronic liver diseases, especially for lifestyles possibly modified after disease onset. The analytic strategy excluding potentially diseased subjects was considered appropriate for identifying risk factors for chronic liver diseases.
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Summary
- A Distribution of Waist-hip Ratio Associated with the Blood Pressure in Middle-aged Men.
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Jong Myon Bae, Dae Sung Kim, Jaiyong Kim, Yoon Ok Ahn
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Korean J Prev Med. 1999;32(3):395-399.
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Abstract
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- BACKGROUND
Excess abdominal fat, expressed as an increased ratio of waist to hip circumferences (WHR), is independently associated with higher levels of blood pressure. Although a WHR greater than 1.0 in men has been shown to predict complications from obesity, the WHR has not been evaluated in all ethnic groups. METHODS: In order to ascertain the association between WHR and classification of blood pressure and to investigate the critical value of WHR as a predictive factor of hypertension in Korean middle-aged men, we compared the mean of WHRs according to the classification of blood pressure in Seoul Cohort participants. RESULTS: Through a survey of direct measurement of waist and hip girth, 452 subjects were recruited from the cohort. The mean of WHR was 0.88 and its standard deviation was 0.04. The mean of WHRs was higher in the systolic blood pressure group (above 140 mmHg), diastolic blood pressure group (above 90 mmHg), and hypertension group than in the systolic blood pressure group (below 140 mmHg), diastolic blood pressure group (below 90 mmHg), and normotensive group, respectively. And WHR of above 0.89 was associated with hypertension (z-value =6.66). CONCLUSIONS: It is necessary for Korean males with WHR greater than 0.89 to recommend the primary prevention and early detection of hypertension.
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Summary
- A Cohort Study of Physical Activity and All Cause Mortality in Middle-aged Men in Seoul.
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Dae Sung Kim, Hye Won Koo, Dong Hyon Kim, Jong Myon Bae, Myung Hee Shin, Moo Song Lee, Chung Min Lee, Yoon Ok Ahn
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Korean J Prev Med. 1998;31(4):604-615.
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- Although previous studies revealed the association of physical activity with mortality rate, it is unclear whether there is a linear trend between physical activity and mortality rate. In this study, the association of physical activity with the risk of all-cause mortality was analysed using Cox's proportional hazard model for a cohort of 14,204 healthy Korean men aged 40-59 years followed up for 4 years(Jan. 1993 - Dec. 1996). Physical activity and other life style were surveyed by a postal questionnaire in December 1992. Total of 14,204 subjects were grouped into quartiles by physical activity. Using death certificate data, 123 deaths were identified. The second most active quartile had a lowest mortality rate with relative risk of 0.44(95% C.I.: 0.23-0.84) compared with most sedentary quartile, showing a J-shape pattern of physical activity-mortality curve. By examining the difference in proportion of cause of the death between most active quartile and the other quartiles, there was no significant difference of proportional mortality from cardiovascular deaths, cerebrovascular deaths or deaths from trauma. The covariates were stratified into two group between which the trend of RR was compared to test the effect modification. There was no remarkable effect modification by alcohol intake, smoking, body mass index, calorie consumption, percent fat consumption. In conclusion, moderate activity was found to have more protective effect on all-cause mortality than vigorous activity and that the J-shape pattern of physical activity-mortality curve was not due to the difference of mortality pattern or effect modification by alcohol intake, smoking, body mass index, calorie consumption and percent fat consumption.
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Summary
- Reliability and Validity of the Korean Version of ISAAC Questionnaire.
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Seong Woo Choi, Yeong Su Ju, Dae Sung Kim, Jae Yong Kim, Ho Jang Kwon, Dae Hee Kang, Sang Il Lee, Soo Hun Cho
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Korean J Prev Med. 1998;31(3):361-371.
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- Recent increases of asthma and allergies in childhood made the need for a standardized approach to international and regional comparisons of their prevalence and severity. To address these issues, "International Study of Asthma and Allergies in Childhood (ISAAC)" is currently underway. In Korea, "Nationwide Study of Asthma and Allergies in Korean Children" began in 1995 according to ISAAC protocol. ISAAC written and video questionnaires were used in this survey, but their reliability and validity were not evaluated properly yet. In this study, our aim was to evaluate the reliability and validity of two kinds of questionnaires and their usefulness in international and regional comparisons. The test and retest of two questionnaires were completed by male(n=110) and female(n=111) middle school students with two and three weeks interval each. Kappa(or weighted kappa) were calculated from each questions and validity coefficients were estimated from those statistics. In Korean version of written questionnaire, the questions for allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and food allergy proved to have high kappa values(or weighted kappa values) and validity coefficients and they can be used in further studies without any correction. But some questions about asthma(especially nocturnal cough, wheezing in exercise, and severe asthma) and drug allergy need to be revised for better understanding to study subjects. Video questionnaire has the same degree of reliability and validity when compared to written questionnaire and this is the unexpected result. Accordingly, it also need to be revised to overcome the racial and cultural differences of the study subjects. In conclusion, the Korean version of written and video questionnaires may be considered to be useful methods in international and regional comparisons of asthma and allergic diseases in childhood after correction of some questions.
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Summary
- Reliability and validity study of a life style questionnaire for elderly people.
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Byiung Joo Park, Dae Sung Kim, Hye Won Koo, Jong Myon Bae
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Korean J Prev Med. 1998;31(1):49-58.
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- The study was done to determine the reliability and validity of a life style questionnaire for the elderly. The questionnaires were sent to 16,524 elderly people who were beneficiaries of Korean Medical Insurance Corporation in Pusan. Among the completed 9,139 questionnaires, 200 were randomly sampled and retested. Finally, 110 duplicates were collected. Weighted kappa-value and Pearson correlation coefficients were estimated to measure the reliability. Validity coefficient was estimated by using reliability coefficient. In self-self responses, reliability coefficients of the most of items were over 0.6 except some physical activity related item. Relatively high reliability was observed in smoking, alcohol related items and anthropometric items. In self-proxy responses, most of the physical activity related items were found to be less reliable than self-self responses. Smoking and alcohol related items were consistently reliable. Male showed higher validity in food related item than female. On the other hand, some of the physical activity related items and smoking and alcohol related items were less valid in male than female. With regard to bias of proxy respondents, offsprings tended to underestimate the frequency of 'house cleaning' and 'kitchen work' and overestimate the height of them. In conclusion, the life style questionnaire was found to be reliable in the most of items. But, some items related with physical activity were found to be somewhat less reliable. Sexual difference on the validity was identified in some items. With regard to bias of proxy respondents, offsprings tended to have bias in part of items of housework and anthropometry.
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Summary
- Development of Questionnaire for Evaluating Health Effect Associated with Air Pollution.
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Yeong Su Ju, Dae Sung Kim, Jong Won Kang, Joo Heon Seong, Dae Hee Kang, Soo Hun Cho, Do Myung Paek
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Korean J Prev Med. 1997;30(4):852-869.
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- This study was conducted to develope and evaluate the reliability and the validity of a questionnaire in order to determine the applicability as a screening tool for estimating environmental exposure and health effects related to air pollution. The questionnaire was developed with adopting some items of others such as ISAAC or ATS-DLD. And then we performed test-retest to 89 middle school students and their mothers at interval of three months. Cohen's Kappa values, weighted Kappa values, Spearman's correlation coefficients, and Pearson's correlation coefficients for each item were computed as reliability coefficients. The validity coefficients and validity coefficient bounds were also obtained by simply using these reliability coefficients. As results, Kappa ranged broadly from 0.10 to 0.61 of the items 'diet', 0.52~0.79 of the environmental tobacco smoke, 0.39~0.44 of the functional categories of surrounding environment, and 0.54~0.63 of the using transportation systems; these items were regarded as confounding factors. For items related to health outcomes, Kappa ranged from -0.02 to 0.37 in the respiratory system of past medical history, and from 0.11 to 0.55 in the current health status. But Kappa of the others were over 0.60. In conclusion, if some items can be corrected or modified, the questionnaire developed in this study can be used as a tool for evaluating environmental exposure and health effects associated with air pollution.
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Summary
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