The Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Diseases (JPHC Study; formerly called “Koseisho Multipurpose Prospective Cohort Study”) began in 1990(Cohort I) and 1993(Cohort II). The JPHC Study covers 11 public health center areas throughout Japan and includes a total of 140, 420 residents. The study's design includes a baseline survey with a self-administered questionnaire on lifestyle and collection of blood and health checkup data; a follow-up system for mortality, migration, and incidence of cancer and cardiovascular diseases; an additional follow-up survey after 5 and 10 years; and distribution of a newsletter. The JPHC study is expected to provide evidence for the prevention and control of cancer and cardiovascular diseases in the 21st century. J Epidemiol, 2001 ; 11 (Suppl) : S3-S7.
The study areas of the Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Diseases (JPHC Study) are distributed throughout Japan and represent both rural and urban communities. These geographical differences yield considerable difference in population, culture, and lifestyle. The mortality rates in the study areas were apparently influenced by these factors. The pattern of standardized mortality ratios (SMRs) for all causes of death (cancer, heart diseases, ischemic heart disease, and cerebrovascular diseases) in each area was different. Age-standardized site-specific cancer mortality rates showed large variation even when compared with corresponding figures of prefectures in Japan. The areas of the JPHC study showed different patterns of SMR for major causes of death. The differences in sitespecific cancer mortality rates for most of the sites are sufficient for epidemiological analyses. J Epidemiol, 2001 ; 11 (Suppl) : S8-S23.
The data collection from cohort subjects at baseline is the core work for prospective study as well as follow-up. We set up 140, 420 cohort subjects (68, 722 men and 71, 698 women) (61, 595 in 1990 as Cohort I and 78, 825 in 1993 as Cohort II) based on resident registry of 29 districts under 11 Public Health Center areas and baseline survey were submitted for them. The survey consisted of the following three components: (1) self-administered questionnaire survey, (2) collection of blood samples (plasma and buffy coat) for deep-freezed storage and (3) collection of health check-up data. All survey were completed during the first five year of each study. Among all cohort subjects, 113, 461 (81%) (53, 375 men and 60, 086 women, 50, 245 in Cohort I and 63, 216 in Cohort II) returned the questionnaire and 49, 011 (35%) (18, 159 men and 30, 852 women, 24, 637 in Cohort I and 24, 374 in Cohort II) provide their blood. The health check-up data were collected from 47, 910 (34%) (17, 276 men and 30, 664 women, 23, 311 in Cohort I and 24, 599 in Cohort II). These data and blood samples serve as basis for the Japan Public Health Center-based prospective Study on cancer and cardiovascular diseases (JPHC Study). J Epidemiol, 2001; 11 (Suppl): S24-S29.
Dietary habit is closely associated with development of cancer and cardiovascular diseases, however little prospective evidence has been published for Japanese, whose dietary habit is substantially different from Western countries. Therefore, frequencies of food consumption, food preference, cooking method and acceptance of dietary advice were investigated at the baseline by two kinds of self-administered food frequency questionnaires. Dietary habits between urban and rural (Tokyo and Osaka vs. others), or between Okinawa and non-Okinawa revealed recognizable differences. The so-called westernized foods such as bread, beef and coffee were more consumed in the urban areas such as Tokyo and Osaka and also in Okinawa. The frequencies of salted food intake such as pickled vegetables and salted seafoods were remarkably low in Okinawa. Cooking methods for meats, seafoods and vegetables were also unique in Okinawa. No distinct geographical difference was shown in food preference and modification of dietary habit by dietary advice. J Epidemiol, 2001 ; 11 (Suppl) : S30-S43.
Smoking and drinking habits at baseline survey among 110, 896 male and female residents aged 40-69 are reported as part of an ongoing prospective population-based cohort in 11 geographically diverse health centers in Japan. The age-adjusted proportion of current and former smokers was 54.8% and 21.8% in males and 8.3% and 2.1 % in females, respectively. Mean age at initiation of smoking in males and females was 20.6 and 27.8 years of age, respectively. In males, the age-adjusted proportion of those who drink almost daily was 49.1 % and that of those who drink almost never was 19.7%, while in females, it was 5.9% and 71.6%, respectively. When compared by health center, the proportion of male current smokers was lower in Miyako and Ishikawa, both located in Okinawa Prefecture, while in females the proportion was higher in urban areas, such as Katsushika and Suita. The proportion of those who drink almost daily in males was higher in Yokote, Kashiwazaki, Katsushika and Suita, and lower in Ishikawa and Miyako, but in Ishikawa and Miyako, the proportion of those who drink at social events was higher. In females, the proportion of those who drink almost daily was higher in urban areas. There was substantial variation in the types of alcohol beverages consumed by males. In contrast, alcohol consumption in females comprised mainly beer. J Epidemiol, 2001 ; 11 (Suppl) : S44-S56.
A self-reported questionnaire on the health status, life habits, and social background was conducted at baseline in the Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Diseases (JPHC study). This report presents the outcome of the study regarding past or family history of various diseases, medical treatment, life habits such as physical labor or sports, and social background among study participants. In both cohorts I and II, prevalent past and family history included hypertension, stroke, and cancer, whereas the prevalence of coronary heart diseases was historically low. The prevalence of a past history of hypertension and stroke was higher in the northern part of Japan, Ninohe, and Yokote, and lower in Okinawa, compared to the other districts. The prevalence of participants with a history of stomach cancer and liver cancer was higher in Arikawa than in other districts. The frequency of participants who took medication from doctors ranged from 20% to 30%, higher in the Tohoku areas, and lower in Okinawa compared to the other districts. All districts showed a high rate of over 70% for the participation rate for basic health examination conducted by the local government, The rate was particularly high in the Tohoku area where a high prevalence of a history of hypertension was found. The frequency of persons who had a chance to participate in sports or physical exercise was high in Okinawa and Suita subcohort 2, although the mean total physical activity (both at work and for leisure time) was lowest in the latter subcohort. No substantial differences were found in compositions of personality among districts. The frequency of more active and positive persons, however, was relatively higher in urban areas and lower in Okinawa compared to the other districts. The association between the differences of health status, life habits, and social background and the occurrence of various lifestyle-related diseases will be clarified in a follow-up study within the JPHC study. J Epidemiol, 2001 ; 11 (Suppl) : S57-S74.
Hormonal status in the body is closely related to the occurrence of estrogen-related cancers. Baseline survey data about the female reproductive system in JPHC study showed different gynecological and gestational profiles in each study area. Late menarche (15-16 y/o) was characteristic in the rural areas. Earlier gestational age and larger number of children were also more common in the rural areas. Baseline survey data, including gynecological past history, frequency of examination for uterine cancers, and so forth, showed some profile of middle aged women in the different areas in Japan. J Epidemiol, 2001 ; 11 (Suppl) : S75-S80.
The standardization committee has carried out standardization of 23 laboratories in the cohort area. They participated in the External Quality Control Survey by the Japan Medical Association. Most laboratories got A or B in evaluation criteria for most test items, but the results of AST, ALT and gamma-GTP were unsatisfactory. As for the lipid standardization, accuracy and precision of all 23 laboratories were satisfactory except for one. Close communication and collaborative study with reference laboratory improved the accuracy control. J Epidemiol, 2001 ; 11 (Suppl) : S81 -S86.
Health check-up data were compared in all 11 populations included in the cohort. The collected sample size was 23, 313 in Cohort I and 24, 654 in Cohort II. Height was greater in two urban populations, and body mass index (BMI) was largest in the two populations in Okinawa prefecture. Blood pressure was higher in the populations in northeast part of Japan and Okinawa prefecture, and lower in Suita. Serum total cholesterol level was higher in Okinawa and two urban populations, and lower in the populations in northeast part of Japan, and in Arikawa and Saku. J Epidemiol, 2001 ; 11 (Suppl) : S87-S93.