Objective. A hospital-based case-control study was conducted to identify characteristics of women at high risk of developing cervical cancer with special reference to sexual behavior in Korea. Methods. Histologically confirmed cases of invasive cervical cancer were selected from the Department of Gynecology, Seoul National University Hospital between September 1992 to May 1995 (n=203). Women with normal pap smear tests and women free of past history of any malignancies were regarded as controls (n=827). Information on risk factors were collected by both a self-administered questionnaire and a direct interview. Results. Uterine cervical cancer risk was higher in women with a less educated spouse (Ptrend=0.0003), women with a family history of cervical cancer (adjusted odds ratio [OR]=2.20., 95% confidence interval [CI] 1.21-4.01), women of shorter height (Ptrend=0.02), women with early age at first full term pregnancy (Ptrend=0.0005), and women who have had multiple full term pregnancies (Ptrend=0.006) by the multiple linear logistic analysis. Particularly noteworthy was a significant decreasing trend in the adjusted OR with the age at first sexual intercourse increasing (Ptrend=0.002) after adjusting the number of sexual partners. The husband's indecent sexual history showed a borderline significance (Ptrend=0.07). Conclusions. This study confirmed that the risk factors of cervical cancer in Korea are similar with those found in other countries. J Epidemiol, 1997; 7 :117-123.
The association between the participation rates of cervical cancer screening programme and implementation methods, concerning data management, participant convenience, promoting participation, and payment, were analyzed. The data regarding the implementation methods were obtained in a nation-wide questionnaire survey. The relationship between the participation rates and implementation methods were assessed using the X -square test and multiple logistic regression analyses. In small municipalities, with a population < 10, 000, items concerning data management, enlisting the assistance of community organizations, fee exemption, and early morning screening were positively associated with the participation. In middle-sized municipalities, with a population 10, 000-49, 999, early morning screening, community organizations, items concerning data management, and sending out letters were positively associated with participation. Saturday/Sunday screening, community organizations, letters and postcards were positively associated with the participation of the older group (50 years) in large municipalities with a population > 50, 000. These results indicate that enlisting the assistance of community organizations and establishing a well-organized data management system are likely to improve participation regardless of municipality size. Other implementation methods must be selected taking into account factors such as municipality population size, as well as the age distribution and characteristics of the target population. J Epidemiol, 1997 ; 7 : 125-133.
Cost-effectiveness analysis for cervical cancer screening in Japan was performed to estimate the cost per life-year saved by the screening; cost-effectiveness ratio (CER). The analysis was made using a simulation model to estimate long-term cost and effectiveness of the screening programs. CER of cervical cancer screening was estimated to be US 40, 604 which was 2.4 times more expensive than that for gastric cancer screening but was about the same as that for colorectal cancer screening. It was within the range of cost-effectiveness of other cancer screening programs financed under the Health and Medical Services Law for the Aged in Japan. We performed sensitivity analysis on the following seven estimates, the screening charge, the sensitivity and the specificity of the screening test, the frequency of carcinoma in situ (CIS) among cases detected in the screening program, the initial cost and the terminal cost for patients with invasive cancer, and the incidence rate of cervical cancer. The sensitivity analysis demonstrated that the screening charge was the most influential factor on CER. CER was fairly stable under various assumptions on the accuracy of the screening test, the frequency of carcinoma in situ (CIS), the treatment cost for patient, and the incidence of cervical cancer. CER was less sensitive to the changes in incidence, even to as low as a 50% decrease of the current figure. Then if the incidence rate becomes 85% of the current figure in 2015, CER would be US 48, 176 and it was suggested that the cervical cancer screening would remain reasonably costeffective until the year 2015. J Epidemiol, 1997 ; 7 : 135-141.
This study was carried out to determine the cutoff levels of serum pepsinogen (PG) I, II and their ratio of PG I /PG II for gastric cancer to establish a better screening system. Optimal cutoff levels for gastric cancer screening using serum pepsinogens were determined using Youden's index. The sensitivity, specificity and Youden's index for gastric cancer cases were calculated according to sex, age and the stage of gastric cancer, and the maximum Youden's index in each category was adopted as the cutoff level for gastric cancer screening using serum pepsinogens. The maximal Youden's index in all gastric cancer cases was 0.37, corresponding to a cutoff level of PG I < 40 (μg/I) and PG I /PG II < 3.5. The sensitivity and specificity for gastric cancer cases of these cutoff levels were 0.50 and 0.87, respectively. In future, better criteria for gastric cancer screening have to be examined with the estimation of Youden's index in addition to other epidemiological methods such as ROC (receiver operating characteristic) curves and/or cost benefit analyses. J Epidemiol, 1997 ; 7 : 143-151.
Misclassification and temporal changes of food consumption frequencies were estimated under the statistical models with some assumptions, and their effects on risk ratios were evaluated. Food frequencies of 27 items in 214 subjects were doubly measured by a questionnaire with 2 weeks interval, and those in 326 subjects were measured in 1989, 1993 and 1994. Median of probabilities of misclassification in responses among 27 food items was estimated to be 0.12. Medians of proportions of persons whose responses in 1989 were different from those after 5 years, were calculated to be 35% with misclassification and 27% without misclassification. For the true risk ratio of 3, medians of the risk ratios of dietary habits during 5 years, based on food frequencies measured at 1989, were observed to be 2.2 in case of responses with misclassification, and 1.7 in case of responses with misclassification and temporal changes. These suggested that the risk ratios of food frequencies would be seriously affected by misclassification and temporal changes in responses. J Epidemiol, 1997 ; 7 : 153-159.
Self-defense officials in Japan are to retire at the age of early 50s. This unique situation prompted the authors to investigate whether preexisting morbid conditions cause any difficulty in finding a post-retirement job and whether anticipation of job loss or job change, as measured by the status of a post-retirement job and months remaining until retirement, was related to biological cardiovascular risk factors. The subjects were 2, 228 male self-defense officials who received a preretirement health examination at three Self-Defense Forces Hospitals from 1991 to 1992; the period in time remaining until retirement ranged from 1-40 months (median 12 months), and 62% had one year or less until the retirement. The defined preexisting illnesses included a wide range of chronic, non-communicable diseases. Overall, the preexisting illness was unrelated to the determination of a post-retirement job. In men having 6 months or less until retirement, however, the security of post-retirement job was less frequent when they had the preexisting illness, especially cardiovascular diseases. In 1, 839 men excluding those with the preexisting illness, the period until retirement was not adversely related to obesity, blood pressure, serum lipids, serum uric acid, or glucose intolerance whether the post-retirement job had been secured or not. The findings suggest that the preexisting illness decreases the chance of obtaining a post-retirement job, but do not provide any evidence that anticipation of job loss or job change due to early retirement exerts an adverse effect on biological cardiovascular risk factors. J Epidemiol, 1997 ; 7 : 161-166.
The isolation rate of the methicillin-resistant Staphylococcus aureus(MRSA) from pharyngeal swab cultures in Japanese elderly was studied at admission to a geriatric hospital. The subjects were 233 consecutive patients admitted to Kitakyushu Tsuyazaki Hospital from April 1994 to March 1996. The isolation rate of MRSA was 3.0% in the patients admitted from their own homes, 9.7% in those transferred from nursing homes and 14.0% in those transferred from other hospitals. The patients from their own homes were younger than those from nursing homes, the latter being older than those transferring from other hospitals. The patients from their own homes had better activities of daily living(ADL), higher levels of hemoglobin and serum albumin than those from nursing homes or other hospitals. The white blood cell counts, and the proportion of patients with positive c-reactive protein or with fever did not differ among the three groups. Multiple logistic regression analysis revealed that fever and ADL disability were independent risk factors for the isolation of MRSA, and hypoalbuminemia was a risk factor for MRSA isolation in the model using serum albumin instead of ADL score. These results suggest that the lower isolation rate of MRSA among patients from their own homes may be partly due to better ADL and nutritional status compared with those from nursing homes or other hospitals. J Epidemiol, 1997 ; 7 : 167-172.
A total of 1840 children and adolescents treated with cyproterone acetate (CPA) to block gonadal function, as a treatment for precocious puberty, short stature and other disorders, were registered to survey for the risk of developing hepatic tumors. Patients responding to follow-up numbered 1552 (85%). The cumulative dose and duration of CPA therapy for boys and girls were 110.4g and 2.6 years, and 122.9 g and 2.8 years, respectively. Among the 1552 patients, five hepatoma cases were found. Four underwent successful surgery and remain alive and well to date. Two of the 5 cases had been given more than 500g, the other 3 more than 1000 g, of CPA. Three had also been given androgens before CPA administration. Although further follow-up is necessary to monitor for the development of adenoma and hepatoma, the risk of developing these tumors among patients to whom limited doses of CPA were administered appears to be negligible. J Epidemiol, 1997 ; 7 : 173-178.