• Journal of Preventive Medicine and Public Health
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• v.35 no.2
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• pp.136-140
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• 2002

Objectives : A common problem with analyzing survey data involves incomplete data with either a nonresponse or missing data. The mail questionnaire survey conducted for collecting lifestyle variables on the members of the Korean Elderly Phamacoepidemiologic Cohort(KEPEC) in 1996 contains some nonresponse or missing data. The proper statistical method was applied to evaluate the missing pattern of a specific KEPEC data, which had no missing data in the independent variable and missing data in the response variable, BMI. Methods : The number of study subjects was 8,689 elderly people. Initially, the BMI and significant variables that influenced the BMI were categorized. After fitting the log-linear model, the probabilities of the people on each category were estimated. The EM algorithm was implemented using a log-linear model to determine the missing mechanism causing the nonresponse. Results : Age, smoking status, and a preference of spicy hot food were chosen as variables that influenced the BMI. As a result of fitting the nonignorable and ignorable nonresponse log-linear model considering these variables, the difference in the deviance in these two models was 0.0034(df=1). Conclusion : There is a lot of risk if an inference regarding the variables and large samples is made without considering the pattern of missing data. On the basis of these results, the missing data occurring in the BMI is the ignorable nonresponse. Therefore, when analyzing the BMI in KEPEC data, the inference can be made about the data without considering the missing data.

• 대한예방의학회:학술대회논문집
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• 2001.10a
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• pp.240-241
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• 2001

• Journal of Preventive Medicine and Public Health
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• v.41 no.1
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• pp.23-29
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• 2008

Objectives : We examined the association between alcohol consumption and incidence of colorectal cancer in elderly Koreans. Methods : The cohort members (n=14,304) consisted of 4,834 males and 9,470 females derived from the Korea Elderly Pharmacoepidemiologic Cohort (KEPEC), a population-based dynamic cohort. They were aged 65 years old or older and lived in Busan between 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). Baseline information was surveyed by a self-administered, mailed questionnaire. This study population was restricted to 14,304 participants who reported alcohol drinking habits on the questionnaire and had not been diagnosed with colorectal cancer at baseline. The adjusted hazard ratios (aHR) of status, type, frequency and daily average amount of alcohol consumption were computed with Cox's proportional hazard model, with the never-drinkers as a reference group and controlling for age and gender. Results : After 4.82 person-years of mean follow-up 112 cases of colorectal cancer occurred. The incidence densities of colorectal cancer were 161 (95% CI=123-200) for never-drinkers, 219 (95% CI=125-339) for ex-drinkers, and 137 (95% CI=84-189) for current-drinkers per 100,000 person-year. The status, type, frequency, and daily average amount of alcohol consumption were not significantly related to the incidence of colorectal cancer after controlling for age and gender. Conclusions : There was no significant association between alcohol consumption and colorectal cancer among elderly people after controlling for age and gender.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.236.2-237
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• 2002

Proximal femur fracture is known as one of the major medical problems in terms of mortality. disability and economic costs. To assess the association between the use of corticosteroids and proximal femur fracture. a cohort study was conducted upon Korean elderly women. (omitted)

• Journal of Preventive Medicine and Public Health
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• v.39 no.2
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• pp.123-129
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• 2006

Objectives : The incidence of colorectal cancer increased greatly among the elderly in Korea, but the relationship between smoking and colon cancer remains controversial. Few studies have targeted Asian elderly people. We analyzed the smoking status, the amount smoked, and the smoking duration as risk factors of colorectal cancer to determine their association and causality. Methods: The cohort members (n=14, 103) consisted of 4,694 males and 9,409 females, and they were derived from the Korea Elderly Phamacepidemilogic Cohort (KEPEC), which was a population-based dynamic cohort. They were aged 65 years or more and they lived in Busan Metropolitan City between from 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). The baseline information was surveyed by a self-administered mailed questionnaire; after 8.7 person-years of mean follow up period, 100 cases of colorectal cancer occurred. The adjusted relative ratio (aRR) of smoking status, the smoking amount and the smoking duration were calculated from the Cox's proportional hazard model with the never-smokers as a reference group and the Cox model controlled for age, gender, precancerous lesions of CRC, medication history of NSAIDs & antibiotics, the alcohol drinking status and BMI. Results : Compared with the never smokers, the aRRs were 2.03 (95% CI=1.02-4.03) and 1.36 (95% CI=0.80-2.32) for the ex-smokers and current smokers, respectively. Statistical significant trends were not observed for the dose-relationship among the elderly, either for the mean daily amount smoked (p for trend=0.28) or for the total amount (p for trend=0.15). Still, the aRRs were 1.51 (95% CI=0.97-2.34) for the elderly who smoked less than 40 years and 2.35 (95% CI=1.16-4.74) for the elderly who had 40 years or more of smoking (p for trend=0.06). Smokers who started smoking before the age 20 had an increased aRR of 2.15 (95% CI=1.17-3.93) compared to the never smokers. Conclusions : After controlling for age, gender, precancerous lesion of CRC, medication history of NSAIDs & antibiotics, the alcohol drinking status and BMI, smoking increases the risk of colorectal cancer among elderly people. The age when starting smoking is also important.

• Journal of Preventive Medicine and Public Health
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• v.35 no.1
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• pp.41-48
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• 2002

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 1594. 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 $H_2$ 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 fetal 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 antiulceratiye agents.

• Journal of Preventive Medicine and Public Health
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• v.35 no.4
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• pp.351-358
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• 2002

Objective : To evaluate the relationship between physical activity and the risk of hip fracture in the elderly Korean people. Methods : The study population was a Physical Activity Subcohort (n=8,908) extracted from the Korean Elderly Pharmacoepidemiological Cohort (KEPEC). Physical activity information was obtained from a mailed questionnaire surveys. The outcome data was collected from claims data gathered between Jan. 1993 and Dec. 1998. A hospital survey relating to potential cases was conducted to confirm the final diagnoses. The abstracted data was reviewed by a medical doctor before the final diagnoses were confirmed. A mailing questionnaire survey was performed to obtain information on potentially confounding variables, including alcohol intake, smoking habits, weight, height and postmenopausal duration. There were 79 confirmed cases hospitalized due to hip fractures between Jan. 1993 and Dec. 1998. Relative risk of physical activity scores on the hip fracture, and their 95% confidence intervals, were estimated by a Cox's proportional hazard model using SAS for Windows ver.6.12. Results : Compared to the reference group, the adjusted relative risk of hip fracture associated with the most physical active category: after controlling for age, weight and alcohol intake in the males, and for weight, alcohol intake and postmenopausal duration in the females, were 1.04 (95% CI=0.35-3.06) and 0.f4 (95% CI=0.26-0.77), respectively. Conclusions : Physical activity may protect elderly women from hip fracture.

• Journal of Preventive Medicine and Public Health
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• v.35 no.4
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• pp.305-312
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• 2002

Objectives : The reproductive history of women has been suggested to have a possible influence on the risk of osteoporotic fractures. The purpose of this study was to assess the association between reproductive history and hip fractures in the elderly women. Methods : The study subjects were drawn from women members of the Korean Elderly Pharmacoepidemiologic Cohort (KEPEC), aged 65 years or over, whose reproductive histories were available, and who were beneficiaries of the Korea Medical Insurance Corporation (KMIC) in 1993 and lived in Busan city, Korea. The information on reproductive histories, and possible confounders, were collected from mailed questionnaires. Potential hip fracture cases were collected from the claims data obtained between 1993 and 1998, with a hospital survey conducted to confirm the final diagnoses. Rate ratios and their 95% confidence intervals, were calculated using a Cox's proportional hazard model. Results : Following up 5,215 women for 6 years, 51 cases were confirmed with hip fractures. When adjusted for age, weight and physical activity, the rate ratio of hip fractures in women who had given birth three or more times was 0.56 (95% CI: 0.25-1.25), compared with those who had given birth two or less times. When adjusted for age, number of births, weight and physical activity, the rate ratio in women who first gave birth when younger than 22 years was 0.60 (95% CI: 0.34-1.08) compared with those who had giving birth at 22 years or older. Conclusions : According to these findings, an early age when first giving birth might decrease the risk of hip fractures in elderly Korean women.

• Journal of Preventive Medicine and Public Health
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• v.35 no.3
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• pp.245-254
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• 2002

Objective : To test if the intake of $H_2$ receptor antagonists ($H_2$-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 1999. The information on $H_2$-RAs exposure was obtained from a drug prescription database compiled between inn. 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 4.4 195% 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 $H_2$-RAs might increase the risk of gastric cancer through achlorhydria in the elderly.