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The Cohort for Childhood Origin of Asthma and allergic diseases (COCOA) study: design, rationale and methods

Hyeon-Jong Yang1, So-Yeon Lee2, Dong In Suh3, Youn Ho Shin4, Byoung-Ju Kim5, Ju-Hee Seo6, Hyoung Yoon Chang7, Kyung Won Kim8, Kangmo Ahn9, Yee-Jin Shin10, Kyung-Sook Lee11, Cheol Min Lee12, Se-Young Oh13, Ho Kim14, Jong-Han Leem15, Hwan-Cheol Kim15, Eun-Jin Kim16, Joo-Shil Lee16* and Soo-Jong Hong7*

Author Affiliations

1 Department of Pediatrics, Soonchunhyang University School of Medicine, Seoul, Korea

2 Department of Pediatrics, Hallym Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea

3 Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea

4 Department of Pediatrics, CHA Gangnam Medical Center, CHA University School of Medicine, Seoul, Korea

5 Department of Pediatrics, Inje University Haeundae Paik Hospital, Busan, Korea

6 Department of Pediatrics, Korean Cancer Center Hospital, Seoul, Korea

7 Department of Pediatrics, Childhood Asthma Atopy Center, Research Center for Standardization of Allergic Diseases, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, 760, Korea

8 Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea

9 Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea

10 Department of Psychiatry, Yonsei University College of Medicine, Seoul, Korea

11 Department of Rehabilitation, Hanshin University, Osan, Korea

12 Institute of Environmental and Industrial Medicine, Hanyang University, Seoul, Korea

13 Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Korea

14 Graduate School of Public Health, Seoul National University, Seoul, Korea

15 Department of Occupational and Environmental Medicine, Inha University School of Medicine, Incheon, Korea

16 Allergy TF, Department of Immunology and Pathology, Korea National Institute of Health, Osong Health Technology Administration Complex, 187 Osongsaengmyeong 2-ro, Yeonjae-ri, Osong-eup, Cheongwon, 363-951, Korea

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BMC Pulmonary Medicine 2014, 14:109  doi:10.1186/1471-2466-14-109

Published: 3 July 2014



This paper describes the background, aim, and design of a prospective birth-cohort study in Korea called the COhort for Childhood Origin of Asthma and allergic diseases (COCOA). COCOA objectives are to investigate the individual and interactive effects of genetics, perinatal environment, maternal lifestyle, and psychosocial stress of mother and child on pediatric susceptibility to allergic diseases.


The participants in COCOA represents a Korean inner-city population. Recruitment started on 19 November, 2007 and will continue until 31 December, 2015. Recruitment is performed at five medical centers and eight public-health centers for antenatal care located in Seoul. Participating mother-baby pairs are followed from before birth to adolescents. COCOA investigates whether the following five environmental variables contribute causally to the development and natural course of allergic diseases: (1) perinatal indoor factors (i.e. house-dust mite, bacterial endotoxin, tobacco smoking, and particulate matters 2.5 and 10), (2) perinatal outdoor pollutants, (3) maternal prenatal psychosocial stress and the child’s neurodevelopment, (4) perinatal nutrition, and (5) perinatal microbiome. Cord blood and blood samples from the child are used to assess whether the child’s genes and epigenetic changes influence allergic-disease susceptibility. Thus, COCOA aims to investigate the contributions of genetics, epigenetics, and various environmental factors in early life to allergic-disease susceptibility in later life. How these variables interact to shape allergic-disease susceptibility is also a key aim.

The COCOA data collection schedule includes 11 routine standardized follow-up assessments of all children at 6 months and every year until 10 years of age, regardless of allergic-disease development. The mothers will complete multiple questionnaires to assess the baseline characteristics, the child’s exposure to environmental factors, maternal pre- and post-natal psychological stress, and the child’s neurodevelopment, nutritional status, and development of allergic and respiratory illnesses. The child’s microbiome, genes, epigenetics, plasma cytokine levels, and neuropsychological status, the microbiome of the residence, and the levels of indoor and outdoor pollutants are measured by standard procedures.


The COCOA study will improve our understanding of how individual genetic or environmental risk factors influence susceptibility to allergic disease and how these variables interact to shape the phenotype of allergic diseases.

Cohort study; Gene-environment interaction; Allergy; Microbiota; Nutritional Status; Psychologic stress