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A robust well-recruited cohort of 3,500 families = an enormous amount of data on the health of Canadians.

CHILD is a national and international resource given its in-depth objective assessments and biological sampling from pregnancy through the first five years of life. A previously conducted Inventory of Pregnancy and Birth Cohort Studies in Canada sponsored by the Canadian Institutes of Health Research (CIHR) highlighted the unique and comprehensive nature of the CHILD study ( expressed in documents apearing in the Strategic Knowledge Cluster on Early Child Development

In particular, it is the only Canadian birth cohort study combining rich environmental objective measurements with substantive longitudinal follow-up beyond birth outcomes. Prospective longitudinal data from over 3,600 children will allow identification of key environmental risk factors relevant to the long-term goal of reducing morbidity of these common disorders by identifying individual and population based 'prescriptions' for prevention or amelioration.

The strengths of the CHILD Study are:

  • its longitudinal multi-disciplinary approach;
  • involves 44 researchers, 11 hospitals, 7 universities located in 4 provinces
  • captures the type, amount and timing of numerous environmental exposures;
  • its capacity for epigenetic evaluations over time;
  • ability to apply sophisticated bioinformatics of critical mechanistic pathways leading from exposure to disease; and
  • over 500,000 aliquots of relevant samples will serve not only address the core asthma/allergy hypotheses of the study, but also to provide the basis for many future investigations of population-based and personalized health and disease.

The following are many of the project deliverables that will be achieved over the next 5 years; several have already been achieved:

  1. Multiple scientific working groups developing and evaluating each component of the study
  2. Over 400 questionnaires have been developed for assessment of mother, father, child and environment from pregnancy to (currently) 4 years in the Vanguard and Main cohorts – follow this link for a list of Questionnaires developed for CHILD
  3. A validated Food Frequency Questionnaire (FFQ) for nutritional assessment has been modified for Canadian use and implemented to obtain maternal nutritional data in pregnancy;
  4. A 158 page illustrated manual for home environmental assessments has been developed in conjunction with experts from the Canadian Mortgage and Housing Corporation;
  5. CHILD Environmental Working Group developed a novel sterile system for collecting house dust to avoid contamination with endotoxin and other matter; this device is now being sought after by other cohorts;
  6. Standardized Operating Procedures (SOPs) have been developed and implemented for numerous procedures ranging from cord blood collection and processing to home inspection and house dust collection – Cord Blood Collection Standard Operating Procedure -- as one example of the many such SOPs developed;
  7. A Data Management Centre has been established, responsible for supervision of centralized data entry of paper-based questionnaires, checking and correcting electronically completed questionnaires, and ensuring highest standards of quality control for all data;
  8. Secure sample storage has been developed using a state-of-the-art facility in Hamilton with meticulous documentation of samples stored; well over 300,000 aliquots of biological material are already in storage, and are being used for appropriate analyses when approved by the CHILD: Biological Samples Committee.
  9. Quality control related to all biological samples is assured at all steps from obtaining the samples, immediate processing and aliquoting as appropriate with freezing at the recruitment site, transfer to the liquid nitrogen storage facility in Hamilton using dry shippers with carefully maintained temperature control, ensuring accurate labeling and documentation of all samples, and tracking their use when released for analysis; and
  10. A National Coordinating Centre that has responded to multiple requests for preliminary data required for grant applications, completion of student theses, and for publications.


WHY STUDY IT ? : Relevance to Canadians

The CHILD birth cohort study is generating important new public health and policy information to examine the origins of allergy, asthma and associated environmental, nutritional and genetic triggers, from pregnancy and throughout childhood.

  1. The goal of the CHILD Study is to reveal the causes of allergic diseases through research into the health consequences of exposure to environmental triggers of allergy in air, food and water in the home environment and even as early as in pregnancy. CHILD will deliver valuable data on pregnant mothers' exposures to allergenic food components, pollens, infections, pollutants, toxicants and all types of psychosocial stress.
  2. Allergy and asthma cost the Canadian economy billions of dollars in healthcare costs and lost productivity. There is an increasing economic and social burden of allergic diseases, especially on families and their children and in the workforce. According to the Phase III ISAAC Study (2003), 47% of Canadian children have suffered from allergic rhinitis; 39% have experienced wheezing; 22.4% have been diagnosed with asthma; and 19% have experienced atopic eczema.
  3. According to Health Canada, non-food allergies are now the most common chronic condition in Canadians 12 years of age and older. The economic impact of these diseases in Canada is in excess of $15 billion annually, when one includes the cost of ambulatory care, in-patient stays, emergency department (ED) visits, physician and facility payments, prescribed medications and productivity losses at school, work and at home. This annual cost is comparable to the economic impact of arthritis and other chronic conditions.
  4. Ontario data show that 14% of all asthma-related ED visits occur in children between birth and four years of age, and that 21% of asthma cases were children and adolescents up to 19 years of age. Globally, asthma is more prevalent among the developed countries and in major city centres. Among the countries with lower prevalence rates, such as India and China, which represent 37% of the global population, recent research suggests that as these countries industrialize and modernize, allergy, asthma and related immune disease rates are rising rapidly, mirroring the experience of more developed countries.
  5. A recent analysis by Teresa To, The Hospital for Sick Children in Toronto, reveals that for Ontarians, the lifetime risk of developing chronic asthma is one in three – the same as the risk of developing cancer and diabetes. However, unlike cancer and diabetes, the substantial lifetime risk of asthma begins early in life and persists throughout the life span, triggering heightened disease burden, productivity loss and other economic costs.
  6. The CHILD Study, linking with AllerGen, provides a significant opportunity to work in global networks to accelerate the translation of research into practice, and knowledge to action, to improve allergic disease and asthma awareness, education, management and control – all of which will have lasting benefits to individuals and society through minimization of downstream, long-term impacts associated with this prevalent childhood chronic disease.


WHY ANALYSE IT ?: Relevance to Government Policy Decisions

The relevance of data already emerging from CHILD is evident in the following statements (see full text of these Health Canada and Environment Canada reports):

  • "Getting the new information needed for better federal air quality policy-setting tools is clearly a long term endeavour with CHILD informing the Canadian government and likely many other governments/agencies around the world responsible for air quality policy."
  • "Without CHILD, no population representative infant urine, cord blood and corresponding house dust specimens would be available in Canada to assess the exposure levels and potential risks posed by phthalates."
  • "There are very limited Canadian data on exposure to infants, to better understand the sources of phthalate exposure in Canadian infants and the potential risk. CHILD is filling this critical gap."

CHILD will have a direct impact on public health-based prevention strategies for asthma and allergic diseases, environmental exposure regulations and policies, safe home product standards and regulations, food safety regulations and policies, urban planning and home design, maternal-child health in Canada and globally, prenatal care (diet, nutrition) guidelines, pediatric allergy and asthma guidelines, and novel therapeutic targets for drug discovery and exposure modulation. CHILD data and biological samples analyzed through collaboration with Health Canada and AllerGen NCE have already provided unique Canadian data on phthalate levels in house dust and in urine in infancy and early childhood. Such information will help guide federal policy on the use of chemicals in products and materials.

Better understanding of causes of allergy and asthma can lead to earlier diagnoses, better management and the potential for development of preventive strategies. The CHILD Study will provide greater understanding of the root causes of allergy and asthma including biological and environmental triggers, translating into:

  1. BETTER HEALTH – One in three Canadians will be diagnosed with an allergic disease over their lifetime, on a level with diabetes, cancer and heart disease. Better understanding of the causes of allergic diseases can lead to earlier diagnoses, better disease management and the potential for development of preventive strategies, translating directly into better health.
  2. BETTER POLICIES– The incidence of allergic diseases is growing. Canada has one of the highest growth rates per capita for these diseases in the world. Better information about causes can lead to policies that generate social and environmental changes that in turn, can slow or reverse the growth of these diseases.
  3. LOWER HEALTH CARE COSTS –There are an estimated 275,000 ED visits annually in Canada for asthma and allergies (the majority are children), with a direct cost of approximately $275 million annually (using a conservative average cost per ED visit of $1,000). Even a 10% reduction in ED visits will result in a direct cost savings of $27 million annually on healthcare care budgets. Indirect savings are substantially greater.
  4. COMPREHENSIVE DATA: Linkage of CHILD data with provincial records of health services and pharmaceutical drug use, and knowledge of parental occupational and residential exposures, psychosocial stress and dietary history will provide a powerful dataset to examine multiple environmental epidemiologic questions in a wide variety of adult chronic diseases beyond asthma and allergies, e.g., diabetes, cancer, obesity, hypertension and cardiovascular disease.
The CHILD platform will be relevant to many different health researchers and disciplines, and to policy makers with respect to environment and health, including the impact of chronic diseases and exposures on the healthcare burden in Canada. Primary data emerging from the CHILD Study will potentially be influential in a wide variety of areas, including but not limited to
  • Public health-based prevention strategies for asthma & allergic diseases
  • Environmental exposure regulations & policies
  • Safe home product standards & regulations
  • Food safety regulations & policies
  • Personalized healthcare
  • Urban planning & home design
  • Maternal-child health in Canada & globally
  • Prenatal care (diet, nutrition) guidelines
  • Pediatric allergy & asthma guidelines
  • Novel therapeutic targets for drug discovery & exposure modulation
  • Strengthen medical education curricula


Data are highly relevant to several government agencies including:

  • Canadian Mortgage Housing Corporation (CMHC)
  • National Research Council - Canadian Commission on Building and Fire Codes - National Building Code of Canada
  • Federal - Health Canada, Environment Canada, Public Health Agency of Canada (PHAC), and
  • Provincial - Ministries of Health, Environment and Science and Technology

CHILD will also set the stage for decades of future analysis and discovery of new diagnostic tests, therapies, public health measures, food and housing standards and regulations, and other innovations to better manage, prevent and even reverse or cure these chronic conditions that impose tremendous health and economic burdens and other impacts on society, especially in an era of rising health costs.


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