Analysis of the cost-effectiveness of antiviral therapies in chronic hepatitis B patients in Korea / 대한간학회지

BACKGROUND/AIMS: The purpose of this study was to evaluate the cost-effectiveness of 1 year and up to 5 years of antiviral treatment for chronic hepatitis B (CHB). METHODS: Two ten-health-state Markov models were developed for CHB patients. The proportion of patients remaining alive in each health state, and healthcare costs and quality-adjusted life years (QALYs) were determined during annual cycles of these Markov models. The total healthcare costs, life years, and QALYs over the 40-year time horizon of the model were calculated. The perspectives of the cost-effectiveness analysis were the Korean healthcare system and the healthcare needs of the CHB patient. RESULTS: Short-course therapy with alpha-interferon or 1-year treatment with pegylated interferon alpha-2a, lamivudine (LMV), or adefovir (ADV) had limited impact on disease progression. In contrast, either LMV-ADV or ADV-LMV as rescue medication administered for 5 years resulted in a more sustained decrease in the rate of disease progression. The cost-effectiveness threshold in Korea was estimated to be approximately 25,000,000 South Korean won. LMV administered for 1 year is cost-effective in comparison with no treatment for both HBeAg-positive and HBeAg-negative CHB patients, but longer duration antiviral therapies administered for up to 5 years in CHB patients were found to be highly cost-effective by international standards. CONCLUSIONS: Antiviral treatment of CHB with LMV or ADV for up to 5 years using the alternative antiviral agent as rescue medication appears to be a cost-effective strategy for both HBeAg-positive and HBeAg-negative CHB patients in Korea. Economic evaluation of antiviral therapies should be studied further and updated, particularly for newer agents.

A Cohort Study on the Association between Psychotropics and Hip Fracture in Korean Elderly Women

To test the hypothesis that the intake of psychotropics may increase the risk of hip fracture, a cohort study was conducted upon elderly Korean women. The Korean Elderly Pharmacoepidemiology Cohort was constructed from members of the Korea Medical Insurance Corporation over 65 yr of age who were living in Busan Metropolitan City in 1993. Study participants (n=6,043) were female respondents to a self-administered question survey. Information on the intake of psychotropics was obtained from the drug prescription database, which contained all psychotropic prescriptions during any hospital admission over the two-year period between January 1, 1993 and December 31, 1994. The cohort follow-up has been conducted with information on hip fracture being collected from the Korea Medical Insurance Corporation medical treatment claims database over the four year period between January 1, 1993 and December 31, 1996. Three hundred and three subjects had received 745 psychotropics prescriptions and 56 cases of hip fracture were found. After adjusting for age, body mass index, and drinking history, it was found that the intake of psychotropics significantly increased the risk of hip fracture (adjusted odds ratio, 4.24; 95% confidence interval, 1.89-9.52). This study suggests that the intake of psychotropics might be an important risk factor for hip fracture in elderly Korean women.

H2 Receptor Antagonists and Gastric Cancer in the Elderly: A Nested Case-Control Study / 예방의학회지

OBJECTIVE: To test if the intake of H2 receptor antagonists (H2-RAs) increases the risk of gastric cancer in the elderly. METHODS: The source population for this study was drawn from the responders to a questionnaire survey administered to the Korea Elderly Pharmacoepidemiological Cohort (KEPEC), who were beneficiaries of the Korean Medical Insurance Corporation, were at least 65 years old, and residing in Busan in 1993. The information on H2-RAs exposure was obtained from a drug prescription database compiled between Jan. 1993 and Dec. 1994. The cases consisted of 76 gastric cancer patients, as confirmed from the KMIC claims data, the National Cancer Registry and the Busan Cancer Registry. The follow-up period was from Jan. 1993 to Dec. 1998. Cancer free controls were randomly selected by 1:4 individual matching, which took in to consideration the year of birth and gender. Information on confounders was collected by a mail questionnaire survey. The odds ratios, and their 95% confidence intervals, were calculated using a conditional logistic regression model. RESULTS: After adjusting for a history of gastric ulcer symptoms, medication history, and body mass index, the adjusted OR (aOR) was 4.6 (95% CI=1.72-12.49). The odds ratio of long term use (more than 7 days) was 2.3 (95% CI=1.07-4.82). The odds ratio of short term use was 4.6 (95% CI=1.26-16.50). The odds ratio of parenteral use was 4.4 (95% CI=1.16-17.05) and combination use between the oral and parenteral routes (aOR, 16.8; 95% CI=1.21-233.24) had the high risk of gastric cancer. The aOR of cimetidine was 1.7 (95% CI=1.04-2.95). The aOR of ranitidine was 2.0 (95% CI=1.21-3.40). The aOR of famotidine was 1.7 (95% CI=0.98-2.80). CONCLUSION: The intake of H2-RAs might increase the risk of gastric cancer through achlorhydria in the elderly.

Drug Utilization Review of Antiulcerative Agents in Korean Elderly Inpatients / 예방의학회지

OBJECTIVES: To review the drug prescription pattern of antiulcerative agents for elderly inpatients. METHODS: The study population comprised inpatients of community hospitals who were members of the Korean Elderly Pharmacoepidemiologic Cohort (KEPEC), aged 65 years or over, beneficiaries of the Korea Medical Insurance Corporation (KMIC) and residing in Busan city in 1993. The drug prescription information was collected from the claims data of hospitals where the cohort members received medical care between January 1993 and December 1994. The information included personal identification, age, gender, diagnosis, drug dosage, date of hospital admission and name of medical institutions where the study subjects received drug prescriptions. The data analysis produced outcomes in terms of distribution of antiulcerative agents by class and by medical institution and trend of relative prescription. Analysis was also performed in terms of combined prescriptions of antiulceratives and drugs that could induce risk from drug interaction with antiulceratives. RESULTS: The number of patients prescribed antiulcerative agents was 1,059 (64.9%) male and 1,724 (65.5%) female among the total inpatients. An antacid and composite agent was the most frequently prescribed antiulcerative agent (70.8%), followed by H2 antagonist (16.0%). Among the potential drugs that could induce risk from drug interaction with the antiulcerative agents, diazepam was the most frequently prescribed. The proportion of diazepam co-prescription was 22.5% of the total cimetidine prescriptions and 14.5% of the total omeprazole prescriptions. CONCLUSIONS: Antiulcerative drugs were frequently prescribed in the elderly inpatients. The adverse drug reaction could possibly be due to drug interaction. The study results could be used as fundamental data for further drug utilization review of antiulcerative agents.

Comparison of Efficiency between Individual Randomization and Cluster Randomization in the Field Trial / 예방의학회지

OBJECTIVES: In large-scale field trials, randomization by cluster is frequently used because of the administrative convenience, a desire to reduce the effect of treatment contamination, and the need to avoid ethical issues that might otherwise arise. Cluster randomization trials are experiments in which intact social unit, e.g., families, schools, cities, rather than independent individuals are randomly allocated to intervention groups. The positive correlation among responses of subjects from the same cluster is in matter in cluster randomization. This thesis is to compare the results of three randomization methods by standard error of estimator of treatment effect. METHODS: We simulated cholesterol data varing the size of the cluster and the level of the correlation in clusters and analyzed the effect of cholesterol-lowering agent. RESULTS: In intra-cluster randomization the standard error of the estimator of treatment effect is smallest relative to that in inter-cluster randomization and that in individual randomization. CONCLUSIONS: Intra-cluster randomization is the most efficient in its standard error of estimator of treatment effect but other factor should be considered when selecting a specific randomization method.

Nested Case-control Study on the Association between Alcohol and the Risk of Proximal Hip Fracture in the Elderly People in Korea / 한국역학회지

OBJECTIVE: To assess the association between alcohol drinking and hip fracture in the elderly people in Korea. BACKGROUND: Hip fracture is known as one of the major health problems because of its high incidence and serious consequences in the elderly people. The association between alcohol consumption and hip fractures has not been directly evaluated yet in Korea. So we conducted a nested case-control study to investigate the relationship between alcohol consumption and hip fracture in the Korean elderly people. DESIGN: Nested case-control study from the Korea Elderly Pharmacoepidemiology Cohort (KEPEC), in Pusan, Korea. METHODS: Seventy incident cases have been selected since 1993, and 280 controls have been matched with the cases by age and gender among the KEPEC. Average alcohol intake was calculated by multiplying frequency and amount of drinking and unit capacity of each alcohol type. Odds ratios of alcohol intake on the hip fracture and their confidence intervals were computed by using multiple logistic regression with Windows version SAS 6.12. RESULTS: The elderly people's drinking rate is lower than the young people in Korea. In univariate analysis, crude odds ratio was 0.26 in male and adjusted odds ratio after contolling for age, smoking status, medication history, physical activity and body mass index was 0.36 in male. So current drinking reduces the risk of hip fracture. Adjusted odds ratio after controlling for age, smoking status, medication history, physical activity and body mass index odds ratio was 0.24 in female with moderate drinking. CONCLUSION: We found that alcohol consumption reduces the risk of hip fracture in the elderly Korean. However, we could not explain the plausible mechanism with our data yet. So, we suggest the further study for elucidating the possible mechanism of the finding including the possible association between nutritional status, alcohol drinking and bone marrow density in the elderly.

Factors Associated with the Use of Pap Test in a Rural Area / 예방의학회지

OBJECTIVES: To construct basic data to develop strategies for achieving higher Pap test coverage rate by evaluating factors associated with the use of Pap test through population-based survey. METHODS: 16.4%(671) of the 4,090 women, who were eligible population for this study, in 3 Myens of Chung-ju City participated in this study voluntarily from July 21 to 26, 1997. After basic physical examination by trained doctors, they were interviewed with structured questionnaire by well-educated interviewers. RESULTS: It shows that only 54.3% of study participants experienced Pap test. The strongest factor which is related with the use of Pap test was the history of having breast screening tests(aOR=8.71, 95% CI=4.25-17.84). Probability of ever having Pap test was also higher in married women(aOR of single=0.46, 95% CI=0.29-0.72), younger(Ptrend<0.05), more educated (Ptrend<0.001), non-smoker (aOR of smoker=0.26, 95% CI=0.12-0.55), women of ever having hepatitis test(aOR=2.60, 95% CI=1.73-3.88) in multiple linear logistic analysis. CONCLUSIONS: This study suggests that several factors significantly associated with the use of Pap test, and especially, high-risk population for cervical cancer such as women of older ages, less educated, living alone are less likely to have the Pap test. We should concentrate on encouraging high-risk women in the use of Pap test to improve Pap test coverage rate.

Cigarette Smoking, Alcohol Consumption, and Breast Cancer in Korea / 한국역학회지

A hospital-based case-control study was conducted to assess the relationship between cigarette smoking, alcohol consumption, and the risk of bgreast cancer in Korea. Histologically confirmed incident cases of breast cancer(n=146) were selected from the inpatients at the Department of Surgery, Seoul National University Hospital and Borame Hospital during 1994 to 1997. Women ithout self-reported past history of any malignandies were regarded as controls and selected at the same hospitals during the same period(n-153). Information on life-styles including cigarette smoking, alcohol drinking, and reproductive history were obtained by direct interview using standardixed questionnaire. Each case was matched with one control by 5-year age category(n=146). Adjusted odds ratios and 90% confidence intervals were estimated by unconditional linear logistic regression model. For smokers, age at first smoking was significantly associated with the breat cancer risk(adjusted OR=14.1, 90% CI=1.24-364.2). Particularly noteworthy was an increasing tendency of the breast cancer risk with the duration of alcohol consumtion in years aong alcohol drinkers(ptrend<0.1). These findings suggest that cigarette smoking at an earlier age and alcohol intake might contribute to the risk factor of breast cancer in Korean women. Further investigation on the association between genetic polymorphism of xenobiotic metabolism enxymes of environmental carcinogens and breast cancer should be needed.

Cohort Study on the Association getween Smoking and Proximal Hip Fracture in the Elderly People in Korea / 한국역학회지

OBJECTIVE: To assess the association between cigarette smoking and hip fracture by using the Korea Pharmacoepidemiology Cohort(KPEC). BACKGROUND: Hip fracture is known as one of the major health problems because of its high incidence and serious consequences in the elderly people. Cigarette smoking, old age, female and low body weight have been reported as risk factors for osteoporosis which is regarded as one of the risk factors for hip fracture. But the relationship between cigarette smoking and hip fracture has not been directly evaluated yet. So we conducted a prospective cohort study to investigate the relationship between cigarette smoking and hip fracture in the Korean elderly. DESIGN: Prospective cohort study on the 8,994 elderly person aged 65 or more in Pusan, Korea between 1993 to 1996. METHODS: The Korea Phamacoepidemiology Cohort(KPEC) has been constructed with three kinds of data sources. One is from the Korea Medical Insurance Corporation; Medical Insurance Claims Database and Enrollee's Database. Other sources are from directly constructed pharmacy database and questionnaire data. incidence density and relative risk of smoking for hip fracture were estimated by using the KPEC database. Age and gender specific incidence density was calculated by dividing the number of hip fracture cases by person-years of the follow-up the cohort. Relative risks and their confidence intervals were computed by using multiple logistic regression by Windows version SAS 6.12. RESULTS: The level of incidence density in female was higher than that in male, which was increasing with age in both gender. In the multivariate analysis, we observed significant relationship between soking and hip fracture in female(PR=1.94(1.01-3.76)) in the larger amount smoking group, after adjusting for the confounders; age, alcohol drinking, medication history, physical activity and body mass index, the relative risk became slightly decreased to 1.70(0.84-3.46). CONCLUSION: Accoding to this result, we suggest that effective anti-smoking campaign should be established as soon as possible for the Korean elderly women.

A Cohort Study of Physical Activity and All Cause Mortality in Middle-aged Men in Seoul / 예방의학회지

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.

Reliability and validity study of a life style questionnaire for elderly people / 예방의학회지

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.

A Case-Control Study on Risk Factors of Uterine Cervix Cancer in Korea / 예방의학회지

A hospital-based case-control study was carried out to investigate the risk factors of uterine cervical cancer in korea. Information on a wide-range of life-styles, which might be related with uterine cervix cancer, has been routinely collected through a dual application of the self-administered questionnaire and the direct interview by a well-trained nurse at the Department of Gynecology, Seoul National University Hospitals since 1992. The number of cervical cancer cases, histologically confirmed at the hospital, were 284. Included were 939 women as controls, who were free of past history of any malignancies. Adjusted odds ratio and 95% confidence limits were based on the unconditional logistic regression model. The multivariate logistic model was constructed under the consideration of biologic characteristics on the natural history of the malignancy. In the multivariate results, the uterine cervical cancer risk was higher in women of shorter height(P(trend) <0.05), less educated spouse (P(trend) < 0.001), multiple marriages(adjusted OR=2,70,95% C.I. 1.64~4.47), ever had a family history (adjusted OR=2.14., 95 % C.I. l.18~3.89), multiparity (P(trend) < 0.001), and early age at first delivery (P(trend) < 0.001). These results strongly suggest that the uterine cervix cancer might be related to the reproductive factors, and probably with sexual behaviour of both women and men in Korea.

Understanding the Meta-analysis; with an Example of the Meta: analysis Paper on the Therapeutic Effect of Variceal Bleeding / 대한간학회지

No abstract available.

An Epidemiologic Study on Death Caused by Cancer in Pusan / 예방의학회지

This study surveyed and measured the level and structure of cancer deaths and their trends over time for offering the fundamental data of the cancer prevention and control in Pusan city in the future. Authors conducted the study of descriptive epidemiology using materials derived from the computerized data of total 3,722 certified cancer deaths in Pusan city from January 1 to December 31, 1993 registered on the National Statistical Office, the Republic of Korea. The obtained results were as follows: 1. According to the total registered cases of deaths(16,331 cases) in Pusan city during 1993, cancer(3,722 cases) and cerebrovascular disease(2,718 cases) were the first and second cause of deaths as 23.1% and 16.9%, respectively. These pattern showed the change between cancer(14.7%) and cerebrovascular disease(18.5%) in order of frequency in comparison to 1982. Also, the total number of cancer deaths was increased in comparison to 1982. The rate of death certification by physicians was 87.1% of all registered deaths, which was increased to 6.8% in comparison to 1982(80.3%). 2. Crude death rate and cancer specific death rate was 4.06 per 1,000 populations and 93.8 per 100,000 populations(male:117.8, female:70.0), respectively. The former was similar to that of 1982, but the latter was increased to 1.6 times as that of 1982. 3. Age-adjusted cancer specific death rate by standardization with whole country population was 111.9(male:141.5, female:106.7) per 100,000 populations, higher than not age-adjusted cancer specific death rate(93.8), and the sex difference was statistically significant with male predominance(p<0.05). 4. Cancer specific death rate by age was generally increased with age and most of cancer deaths(male:91.8%, female:88.5%) occurred since 40 years old. 5. The major cancer(cancer specific death rate per 100,000 populations) in male was liver(30.6) followed by stomach(25.6), lung(21.9), and GB and EHBD(5.7), in female stomach(15.7), liver(9.9), lung(7.3), and uterus(6.9). The relative frequency of the leading three cancer among total cancer deaths marked 66.3% in male and 47.1% in female, and decreased in comparison to 1982(male:72.2%, female:54.5%). 6. The total ratio of male to female cancer specific death rate showed 1.68 to 1 with male predominance. And the ratio was above 2.0 in larynx, oral cavity & pharynx, esophagus, liver, lung, bladder cancer and the ratio was 1.0~1.9 in stomach, pancreas, gall bladder and EHBD, brain, rectum and anus cancer, leukemia, but the ratio was reversed in thyroid and colon cancer. In conclusion, cancer was the first cause of deaths. The proportion of lung cancer was increased, that of stomach & uterine cancer was decreased relatively, and liver cancer was constantly higher proportion. In the future, it is necessary to conduct the further investigations on the cancer risk factors considering areal specificity.