Yamamoto, M., Fujita, M., Mori, C., & Hata, A.; “Survey of motivation to participate in a birth cohort;” Journal of Human Genetics, 2016, 61(9), 787-791; DOI: 10.1038/jhg.2016.60.

ABSTRACT:

For a longitudinal prospective cohort study to be successful, participants’ motivation to provide information must be maintained. Therefore, this study aimed to identify items that effectively promote participants’ motivation. Questionnaires were mailed to 4541 mothers and expectant mothers in Chiba Prefecture, Japan who participated in a nationwide birth cohort. A total of 2387 (52.6%) responses were received. The following items were identified as primary motivating factors among our cohort: “benefits to the participants’ children”, “monetary compensation” and “contribution to a better future environment”. More than 30% of the respondents expressed a lack of understanding regarding the study purpose and requirements for participation. About 14% were concerned about the leakage of personal information, and 13% felt burdened by having to make a long-term commitment to the study. Cluster analysis identified four groups, two of which, one with extremely low levels of motivation and the other motivated by only money or goods, lacked an understanding of the study and tended to be concerned about the associated risks and burdens. Participants in these groups were considered to be at a high risk of dropout. Therefore, implementing measures to provide participants with a better understanding of cohort studies could lead to more successful results. FULL TEXT

Michikawa, T., Nitta, H., Nakayama, S. F., Yamazaki, S., Isobe, T., Tamura, K., Suda, E., Ono, M., Yonemoto, J., Iwai-Shimada, M., Kobayashi, Y., Suzuki, G., Kawamoto, T., Japan, Environment, & Children’s Study, Group; “Baseline Profile of Participants in the Japan Environment and Children’s Study (JECS);” Journal of Epidemiology, 2018, 28(2), 99-104; DOI: 10.2188/jea.JE20170018.

ABSTRACT:

BACKGROUND:

The Japan Environment and Children’s Study (JECS), known as Ecochil-Chosa in Japan, is a nationwide birth cohort study investigating the environmental factors that might affect children’s health and development. We report the baseline profiles of the participating mothers, fathers, and their children.

METHODS:

Fifteen Regional Centres located throughout Japan were responsible for recruiting women in early pregnancy living in their respective recruitment areas. Self-administered questionnaires and medical records were used to obtain such information as demographic factors, lifestyle, socioeconomic status, environmental exposure, medical history, and delivery information. In the period up to delivery, we collected bio-specimens, including blood, urine, hair, and umbilical cord blood. Fathers were also recruited, when accessible, and asked to fill in a questionnaire and to provide blood samples.

RESULTS:

The total number of pregnancies resulting in delivery was 100,778, of which 51,402 (51.0%) involved program participation by male partners. Discounting pregnancies by the same woman, the study included 95,248 unique mothers and 49,189 unique fathers. The 100,778 pregnancies involved a total of 101,779 fetuses and resulted in 100,148 live births. The coverage of children in 2013 (the number of live births registered in JECS divided by the number of all live births within the study areas) was approximately 45%. Nevertheless, the data on the characteristics of the mothers and children we studied showed marked similarity to those obtained from Japan’s 2013 Vital Statistics Survey.

CONCLUSIONS:

Between 2011 and 2014, we established one of the largest birth cohorts in the world.

FULL TEXT

Michikawa, T., Nitta, H., Nakayama, S. F., Ono, M., Yonemoto, J., Tamura, K., Suda, E., Ito, H., Takeuchi, A., Kawamoto, T., Japan, Environment, & Children’s Study, Group; “The Japan Environment and Children’s Study (JECS): A Preliminary Report on Selected Characteristics of Approximately 10 000 Pregnant Women Recruited During the First Year of the Study;” Journal of Epidemiology, 2015, 25(6), 452-458; DOI: 10.2188/jea.JE20140186.

ABSTRACT:

BACKGROUND:

The Japan Environment and Children’s Study (JECS) is an ongoing nationwide birth cohort study launched in January 2011. In this progress report, we present data collected in the first year to summarize selected maternal and infant characteristics.

METHODS:

In the 15 Regional Centers located throughout Japan, the expectant mothers were recruited in early pregnancy at obstetric facilities and/or at local government offices issuing pregnancy journals. Self-administered questionnaires were distributed to the women during their first trimester and then again during the second or third trimester to obtain information on demographic factors, physical and mental health, lifestyle, occupation, environmental exposure, dwelling conditions, and socioeconomic status. Information was obtained from medical records in the first trimester and after delivery on medical history, including gravidity and related complications, parity, maternal anthropometry, and infant physical examinations.

RESULTS:

We collected data on a total of 9819 expectant mothers (mean age = 31.0 years) who gave birth during 2011. There were 9635 live births. The selected infant characteristics (singleton births, gestational age at birth, sex, birth weight) in the JECS population were similar to those in national survey data on the Japanese general population.

CONCLUSIONS:

Our final birth data will eventually be used to evaluate the national representativeness of the JECS population. We hope the JECS will provide valuable information on the impact of the environment in which our children live on their health and development. FULL TEXT

Kawamoto, T., Nitta, H., Murata, K., Toda, E., Tsukamoto, N., Hasegawa, M., Yamagata, Z., Kayama, F., Kishi, R., Ohya, Y., Saito, H., Sago, H., Okuyama, M., Ogata, T., Yokoya, S., Koresawa, Y., Shibata, Y., Nakayama, S., Michikawa, T., Takeuchi, A., Satoh, H., & Working Group of the Epidemiological Research for Children’s Environmental, Health; “Rationale and study design of the Japan environment and children’s study (JECS);” BMC Public Health, 2014, 14, 25; DOI: 10.1186/1471-2458-14-25.

ABSTRACT:

BACKGROUND:

There is global concern over significant threats from a wide variety of environmental hazards to which children face. Large-scale and long-term birth cohort studies are needed for better environmental management based on sound science. The primary objective of the Japan Environment and Children’s Study (JECS), a nation-wide birth cohort study that started its recruitment in January 2011, is to elucidate environmental factors that affect children’s health and development.

METHODS/DESIGN:

Approximately 100,000 expecting mothers who live in designated study areas will be recruited over a 3-year period from January 2011. Participating children will be followed until they reach 13 years of age. Exposure to environmental factors will be assessed by chemical analyses of bio-specimens (blood, cord blood, urine, breast milk, and hair), household environment measurements, and computational simulations using monitoring data (e.g. ambient air quality monitoring) as well as questionnaires. JECS’ priority outcomes include reproduction/pregnancy complications, congenital anomalies, neuropsychiatric disorders, immune system disorders, and metabolic/endocrine system disorders. Genetic factors, socioeconomic status, and lifestyle factors will also be examined as covariates and potential confounders. To maximize representativeness, we adopted provider-mediated community-based recruitment.

DISCUSSION:

Through JECS, chemical substances to which children are exposed during the fetal stage or early childhood will be identified. The JECS results will be translated to better risk assessment and management to provide healthy environment for next generations. FULL TEXT

Iwai-Shimada, M., Nakayama, S. F., Isobe, T., Michikawa, T., Yamazaki, S., Nitta, H., Takeuchi, A., Kobayashi, Y., Tamura, K., Suda, E., Ono, M., Yonemoto, J., Kawamoto, T., Japan, Environment, & Children’s Study, Group; “Questionnaire results on exposure characteristics of pregnant women participating in the Japan Environment and Children Study (JECS);” Environmental Health and Preventative Medicine, 2018, 23(1), 45; DOI: 10.1186/s12199-018-0733-0.

ABSTRACT:

BACKGROUND:

The Japan Environment and Children’s Study (JECS) is a nation-wide birth cohort study investigating environmental effects on children’s health and development. In this study, the exposure characteristics of the JECS participating mothers were summarized using two questionnaires administered during pregnancy.

METHODS:

Women were recruited during the early period of their pregnancy. We intended to administer the questionnaire during the first trimester (MT1) and the second/third trimester (MT2). The total number of registered pregnancies was 103,099.

RESULTS:

The response rates of the MT1 and MT2 questionnaires were 96.8% and 95.1%, respectively. The mean gestational ages (SDs) at the time of the MT1 and MT2 questionnaire responses were 16.4 (8.0) and 27.9 (6.5) weeks, respectively. The frequency of participants who reported “lifting something weighing more than 20 kg” during pregnancy was 5.3% for MT1 and 3.9% for MT2. The Cohen kappa scores ranged from 0.07 to 0.54 (median 0.31) about the occupational chemical use between MT1 and MT2 questionnaires. Most of the participants (80%) lived in either wooden detached houses or steel-frame collective housing. More than half of the questionnaire respondents answered that they had “mold growing somewhere in the house”. Insect repellents and insecticides were used widely in households: about 60% used “moth repellent for clothes in the closet,” whereas 32% applied “spray insecticide indoors” or “mosquito coil or an electric mosquito repellent mat.”

CONCLUSIONS:

We summarized the exposure characteristics of the JECS participants using two maternal questionnaires during pregnancy. FULL TEXT

Ishitsuka, K., Nakayama, S. F., Kishi, R., Mori, C., Yamagata, Z., Ohya, Y., Kawamoto, T., & Kamijima, M.; “Japan Environment and Children’s Study: backgrounds, activities, and future directions in global perspectives;” Environmental Health and Preventive Medicine, 2017, 22(1), 61; DOI: 10.1186/s12199-017-0667-y.

ABSTRACT:

There is worldwide concern about the effects of environmental factors on children’s health and development. The Miami Declaration was signed at the G8 Environment Ministers Meeting in 1997 to promote children’s environmental health research. The following ministerial meetings continued to emphasize the need to foster children’s research. In response to such a worldwide movement, the Ministry of the Environment, Japan (MOE), launched a nationwide birth cohort study with 100,000 pairs of mothers and children, namely, the Japan Environment and Children’s Study (JECS), in 2010. Other countries have also started or planned large-scale studies focusing on children’s environmental health issues. The MOE initiated dialogue among those countries and groups to discuss and share the various processes, protocols, knowledge, and techniques for future harmonization and data pooling among such studies. The MOE formed the JECS International Liaison Committee in 2011, which plays a primary role in promoting the international collaboration between JECS and the other children’s environmental health research projects and partnership with other countries. This review article aims to present activities that JECS has developed. As one of the committee’s activities, a workshop and four international symposia were held between 2011 and 2015 in Japan. In these conferences, international researchers and government officials, including those from the World Health Organization, have made presentations on their own birth cohort studies and health policies. In 2015, the MOE hosted the International Advisory Board meeting and received constructive comments and recommendations from the board. JECS is a founding member of the Environment and Child Health International Birth Cohort Group, and has discussed harmonization of exposure and outcome measurements with member parties, which will make it possible to compare and further combine data from different studies, considering the diversity in the measurements of variables between the studies. JECS is expected to contribute to the international environmental health research community and policy-making. More international collaboration would enhance our understanding of the possible environmental causes of diseases and disabilities.  FULL TEXT