Age is a major variable to be considered in epidemiology. But age of family members is not considered at all or its consideration seems inadequate in studies on assessing the family history of coronary heart disease as a risk factor. In this report the effects resulting from disregarding age of a family member in such studies were estimated. Age-specific prevalence of the past history of coronary heart disease among 17, 926 family members was obtained from the results of a questionnaire survey of 1, 716 high school students. From the analysis of the age-specific prevalence by the logistic regression model, an odds ratio was estimated which indicated a risk ratio resulting from a difference in age. The odds ratio obtained was 1.065 (95% confidence interval: 1.0601.071). This meant that the odds created by age difference depended on (1.065)n, where n was age difference in years. Thus, the effects of disregarding age of family members in assessing the family history of coronary heart disease can be substantial. If the age difference is greater than 5, its effect expressed by odds becomes larger than 1.370. Some measures to control age of family members need to be taken, especially if the age difference of compared families is not small. J Epidemiol. 1995; 5 : 109-112.
Lung cancer became the leading cause of cancer deaths among males in Japan in 1993. Smoking is a major attributable risk of lung cancer. Many other diseases, such as cardiovascular and chronic obstructive respiratory disease are also related to the smoking habit. The Japanese government and the public will have to pay more social cost of smoking in the future. We estimated the social cost of smoking from 1990 to 2030 through computerized simulation introducing effective variables to assess the costs, such as medical treatment, loss of life, fire, etc. The stochastic process called Ito process and financial engineering techniques are employed for making the model. The result showed that the social cost of smoking is expected to grow and reach 2.01 and 3.32 times in the year of 2010 and 2030, respectively. Fifty percent reduction of tobacco consumption could not reduce the social cost, which still climbs up to mark 1.58 in 2020. Should Japan succeed in reducing tobacco consumption by 20% per annum starting from 1996, the social cost would peak out at 1.30 in 2001 and come down to 0.93 in 2030. We estimate that 11 trillion yen (US$ 110 billion) per annum of social cost can be saved in and around 2030 in this case. A proper development of medical economics and public health policy should be an important factor to bring fourth a sound and healthy society in the next century. J Epidemiol. 1995; 5 : 113-116.
In order to evaluate the risk factors on the mortality of the institutionalized Japanese elderly, the cohort study was carried out. We studied the outcome of 114 residents in a skilled nursing home for the elderly in Fukuoka, Japan. Sixty-seven of the residents were demented. During the five-and-a-half year follow-up, the survival rate was lower in the residents with than in those without dementia. (31% vs. 70%). In a univariate analysis, the risk for death increased when factors such as age or systolic blood pressure increased, while it decreased when factors such as the score of Hasegawa's dementia rating scale, the serum albumin level or the activity of daily living score increased. The existence of hypertension, cancer or dementia increased the risk for death, while the ability to urinate and have bowel movements by oneself or that to take meals by oneself decreased it. In a multivariate analysis, dementia, old age, high systolic blood pressure, cancer and the inability to take meals by oneself were risk factors for mortality. Since the treatment of hypertension may sometimes accelerate dementia and limit activities of daily living through a further decreased cerebral blood flow after a blood pressure fall, it seems to be advisable to avoid an excessive blood pressure fall while the treatment of hypertension may be recommended in the elderly. J Epidemiol. 1995; 5 : 117-123.
To estimate the prevalence of Sjogren's syndrome (SS) in Japan, and to describe the clinicoepidemiological features, a nationwide epidemiological survey was conducted in 1994. The study consisted of two questionnaires distributed to the relevant departments of hospitals throughout Japan. The first questionnaire inquired the number of the patients treated in 1993, and the second one detailed clinico-epidemiological information of the patients reported. Following major epidemiological findings emerged from the study : (a) The total number of patients treated for SS in 1993, in Japan, was estimated as 17, 000 (95% confidence interval 15, 000-20, 000). The estimated crude prevalence rates were 1.9 and 25.6 per 100, 000 population in males and females, respectively. (b) The ratio of female to male patients was 13.7. The peak of age distribution of SS patients reported was in their fifties. The highest prevalence rate was observed among females with their sixth decade ; being 62.2 per 100, 000 population. J Epidemiol. 1995; 5 : 125-129.
In order to develop the distributed database management system for total health care management on the Internet (the world wide computer network) as an infrastructure, a new distributed type network-based database management system using the electronic mail (e-mail) system was reported in this paper. The basic architecture of this system is as follows ; (1) the history management server stores only the consultation record of about 100, 000-population, (2) it also indicates the medical consultation records and health care histories (when, where, and summary of medical procedures) of the each person when it is required, (3) the facility management system stores the raw data of each person and sends it when the patient or doctor makes a request through the history management server. A model system was built using the e-mail system in an Internet environment on a UNIX* workstation as an experiment. The performance of this model was considered to be adequate for practical use since the basic facilities can be easily set up. J Epidemiol. 1995; 5 : 131-140.
The rare allele frequency of the restriction fragment length polymorphism (RFLP) with Xba I (X+) at the apolipoprotein B (apo B) gene locus was 0.041 in men and 0.026 in women in H-Y district, Shiso County, Hyogo Prefecture, Japan : EcoR I at apo B gene (E-)=0.073 and 0.076, Msp I at apo Al-CIII gene (M-)=0.423 and 0.430, and Sac I at apo Al-CIII gene (S+)= 0.309 and 0.349. There was no marked ageor sex-difference in the frequencies. The frequencies of X+ and Ewere lower and those of S+ and Mwere higher in H-Y district than in Caucasian populations. In this population, according to the ANOVAs, the genotype for EcoR I was significantly (p<0.05) associated with serum total cholesterol, LDL cholesterol and apo B in women, and the genotype for Sac I with serum triglycerides and Msp I with serum apo CIII in men. The absolute values of Spearman correlation coefficients between genotypes and serum lipids or apolipoproteins were less than 0.2 after adjustment for age. J Epidemiol., 1995; 141-151.
To assess the relation of lifestyle factors, personality and some biologic markers to cancer incidence, and to evaluate the effectiveness of cancer screening, a cohort study was conducted among all residents aged 40 to 64 years in 14 municipalities of Miyagi Prefecture, Japan. The baseline survey consisted of self-completed questionnaires concerning lifestyle and personality (Eysenck Personality Questionnaire-Revised), and serum samples collected from a part of the subjects. The proportion of the subjects who appropriately responded to the lifestyle questionnaire (response rate) was 91.7% (47, 605 persons of the total 51, 921 residents), indicating that representative data could be obtained. Of these, 41, 442 persons (87.1%) also completed a personality questionnaire, and serum samples were collected from 8, 896 persons (18.7%). Linkage of these baseline data with the cancer incidence data of a population-based cancer registry, and with the records of cancer screening at a cancer detection center will provide useful information for comprehensive cancer prevention. J Epidemiol. 1995; 5 : 153-157.