Examine the impact of low-level exposures (pre- and postnatal) to prevalent neurotoxicants on health, growth, and neurobehavioral outcomes including broad development, language, cognition and achievement, executive functioning, spatial reasoning, behavior and mood.
Conduct a nested, randomized controlled trial to test the efficacy of lead hazard controls on blood lead concentrations and neurodevelopment, and the efficacy of injury hazard controls on injury incidence and severity.
Recruitment & Enrollment
The recruitment of pregnant women began in March 2003 and was completed in January 2006. The recruitment strategy was developed with the active participation of a local Community Advisory Board and a National Oversight Panel who reviewed the study and provided guidance in addressing research ethics, study design and reporting results to participants. We identified women by using the medical scheduling systems of 9 obstetric practices affiliated with three hospitals in Cincinnati.
5,512 letters were mailed to pregnant women for recruitment. Of these, we surveyed 5,184 (94%) women to determine eligibility. Of the 1,263 eligible women, 468 (37%) initially agreed to participate. At the recommendation of our Community Advisory Board, we instituted a “run-in” period prior to randomization. Once a woman agreed to participate and signed the informed consent form, we delayed a baseline home visit to give her time to thoroughly discuss the study with her family or friends.
Please note: The HOME study is not currently recruiting new participants but continues to follow those who were previously enrolled.
Lead & Injury Hazard Control
The purpose of the randomized trial was to test the efficacy of interventions to prevent lead toxicity and residential injuries in children. All participants were enrolled during pregnancy with the intention of following children until 3 years of age to measure outcomes. In April 2007, the NIEHS awarded additional funds to extend the study to follow children until they were 5 years of age. The extension of this trial was essential to test the efficacy of the intervention on measures of cognitive abilities and behavioral problems that are not stable until 5 years of age.
It was also essential to test the efficacy of the injury intervention during the first 5 years of life, when children are particularly vulnerable to residential injury. Enrolled families were randomly assigned to either the lead hazard reduction arm or the injury reduction arm of the study. There were 174 families assigned to the lead hazard treatment group and 181 assigned to the injury treatment group. The remaining 53 participants fell into a “no intervention” control arm because property owners did not consent to the lead/injury hazard reduction repairs or the participant gave birth before completion of the baseline visit and randomization.
We conducted the lead hazard controls prior to birth, before the children were exposed to lead in their home environment. The injury intervention was implemented when the index child was between 3 and 6 months of age. If a child in the lead treatment group relocated during the first 24 months of life, we conducted lead hazard controls in the new residence if hazards were present. If a child in the injury treatment group relocated during the first 30 months of life, we conducted injury hazard controls in the new residence if hazards were present.