Overview of National Children’s Study -Goals, Study Design, Progress
Dean Baker, MD, MPHMary CogginsUniversity of California, Irvine
November 19, 2009Orange County Vanguard Center
Topics
• National Children’s Study overview
• Rationale and key concepts
• Priority exposures and outcomes
• Benefits of the NCS
• Study design and data collection
• Neighborhood (segment) sampling in Orange County
• Data collection milestones
• Community Outreach and Engagement
Facts about the NCS
• National in scope; the study group will be representative of all US families•100,000 children & parents from 105 US counties
• Families followed from before conception or in early pregnancy until child is age 21 years
• Comprehensive study with priority exposures and outcomes
• Specimens (e.g., household dust, mother’s blood) will be stored, to answer questions in the future
Rationale for the National Children’s Study
President’s Task Force on Environmental Health and Safety Risks to Children, 2000
• Compared to adults, children may be especially vulnerable to environmental exposures – metabolism, behavior
• Exposures to some agents demonstrate potential for serious developmental effects – lead, prenatal alcohol
• Known exposures of high frequency: pesticides, violence, media
• Numerous high burden conditions with suspected environmental contribution – learning disabilities, autism, diabetes, asthma, birth defects, premature birth
• Existing research too limited in size and scope to answer these questions
• Life-course (longitudinal) design needed to correctly link multiple exposures and multiple outcomes
PL 106-310: Children’s Health Act of 2000
(a) PURPOSE — … to authorize NICHD to conduct a national longitudinal study of environmental influences (including physical, chemical, biological, and psychosocial) on children's health and development.
(b) The Director of NICHD shall establish a consortium of representatives from appropriate Federal agencies to:
(1) plan, develop, and implement a prospective cohort study, from birth to adulthood, to evaluate the effects of both chronic and intermittent exposures on child health and human development; and
(2) investigate basic mechanisms of developmental disorders and environmental factors, both risk and protective, that influence health and developmental processes…
Study Concepts
• Study high priority and burdensome conditions
• Large study population to address complex causation of important conditions (n~100,000)
• Hypothesis driven
• Exposure period begins with pregnancy
• Study environment and genetic interactions
• State-of-the-art technology
• National resource for future studies
Conceptual Model: Exposures, Interactions, Mediators, and Outcomes
Obesity and GrowthObesity and Growth
AsthmaAsthma
Neurodevelopment and BehaviorNeurodevelopment and Behavior
Pregnancy OutcomesPregnancy Outcomes
Child Health and DevelopmentChild Health and Development
InjuryInjury
Reproductive DevelopmentReproductive Development
Gene Expression
Gene Expression
HealthCare
HealthCare
Chemical ExposuresChemical Exposures
Physical ExposuresPhysical Exposures
Psychosocial ExposuresPsychosocial Exposures
Biological ExposuresBiological Exposures
GeneticsGenetics
Exposures Mediator Examples
Outcomes
Priority Exposures and Health Outcomes
Priority Exposures
Examples
Physical EnvironmentHousing quality, neighborhood
Chemical ExposuresPesticides, phthalates, heavy metals
Biologic EnvironmentInfectious agents, endotoxins, diet
GeneticsInteraction between genes and environment
Psychosocial milieu
Family structure, socio-economic status, parenting style, social networks, exposure to media and violence
Priority Health Outcomes
Examples
Pregnancy Outcomes Preterm, birth defects
Neurodevelopment and Behavior
Autism, learning disabilities, schizophrenia, conduct and behavior problems
InjuryHead trauma, injuries requiring hospitalizations
AsthmaAsthma incidence and exacerbation
Obesity and Physical Development
Obesity, diabetes, altered puberty
Potential Impact of NCS on Our Children’s Well-Being
• Identify social and environmental factors which cause or contribute to health, development, and behavior problems
• Understand the biology and genetics of health, development, and behavior
• Information on which to base decisions about policies regarding children’s health
• Economic benefits: cost avoidance
• Resource for future research
Potential Cost-Benefit Impact of NCS on Selected Health Outcomes
• Estimated annual disease burden from 10 health outcomes is approximately $395 billion• Includes direct medical spending and indirect costs from
reduced productivity
• Estimated annual reduction of $4.0–9.7 billion (1.0 –2.5%) attributable to the NCS
• Estimated annual cost of study: $0.1 billion - represents a 40:1 to 97:1 return on investment
Pivetz T et al., Battelle, April 2004
National Children’s Study - Sample Design
All Births in the Nation
Sample of Study Locations
Sample of Study Segments
Sample of Study Households
Sample of Study Women
105 Locations(counties)
Selection of neighborhoods
All eligible women in the household
~4 million births in 3,141
counties
All or a sample of households within
neighborhoods
NCS Study Locations
OrangeCounty
Selection of Segments in County
• Orange County has 45,000 births per year. The target enrollment is 250 births per year.
• Multi-stage sampling plan:
•Strata: 15 geographical strata with equal number of births
•Segment: 1,850 segments with ~ 25 births/year each
• Segments consist of contiguous US census blocks that are aggregated to have equal number of births
• The NCS Coordinating Center randomly selected one segment from each Strata
Orange County – Strata
Orange County – Sampled Segments
Single family and multi-household dwellings – some behind gates
Dense apartments – many with gates
Household Screening and Recruitment (EPSC)
• Door-to-door recruitment in segments
•Contact ~ 10,500 households
•Enroll women 18 to 49 years of age (~ 7,000)
• Follow-up of women for 5 years for pregnancy
•Intensity of follow-up depends on likelihood of pregnancy
• Women in sampled neighborhoods who become pregnant will be enrolled in study
• Household recruitment will be supplemented:
•Prenatal care providers
Schedule of Participant Visits
• 14 face-to-face contacts over 21 year study period
• Contacts most frequent early in the study
• Between visits: ongoing data collection by phone, PDA, etc.
Enrollment 3 years
1st Trimester 5 years
2nd Trimester 7 years
3rd Trimester 9 years
Delivery 12 years
6 months 16 years
12 months 20 yearsWhite = homeBlue = clinicRed = hospital
Data Collection
• Questionnaires and Interviews•Face to face
•Remote (computer, telephone, mail)
•Diaries
• Examinations •Clinical and behavioral assessments
• Biologic samples •blood, urine, cord blood, placenta, breast milk
• Environmental samples and observations •Air, dust, soil, water, home observations
T1 Home Visit – Data Collection Equipment and Supplies
Birth Visit – Data Collection at Birthing Hospitals
> 3,000 births/yr
OCVC Milestones - EPSC
• Enumeration – 10,503 dwelling units- Completed enumeration – 8,524 (82%)
• Refusal/ineligible DU – 174• With eligible female – 3,654 (37%) of DU
• Pregnancy Screen - 4,449 eligible females- Completed pregnancy screen – 3,946
• Refusal/ineligible females – 226• Eligible non-pregnant females – 2,931• Eligible Pregnant females – 70
• Pregnant Women Informed Consent• Refused – 6• Agreed to Participate – 48
OCVC Milestones – Data Collection
• T1/T2/T3 Pregnancy Visits- 27 completed & partially completed T1 visits
- 4 T2 ultrasounds
- 6 completed & partially completed T3 visits
• Father Visits- Beginning November 2009
• Birth Visits- First birth - September 17, 2009
- More in October and November
Orange County – Special Characteristics for Recruitment
• Highly populous county with many births
•45,000 births per year with NCS target of 250/year
•Births in segments are < 0.5% of births in county
• Highly diverse population with multiple primary languages and cultures
•English, Spanish, Chinese, Korean, Vietnamese, Persian
• Many restricted access communities
•Home owner associations, gated communities,locked apartment buildings
Community Outreach & Engagement Strategies
• Multi-prong approach
• Multi-level media outreach
• Neighborhood Advisory Committee (NAC) for each segment•Community group representatives and residents in
segments
• Formed or facilitated additional support groups•e.g., Korean Leadership Forum
• Monthly newsletter distributed via e-mail
Multi-Pronged Outreach Strategy
Multi-level Media Outreach
Events
Neighborhood Advisory Committees (NAC’s)
•gather unique segment characteristics
•share segment contacts
•tap into existing community networks
•help to identify key segment informants
•support continuous segment surveillance throughout recruitment
NAC - Breakfast of Champions