Fig. 2From: The Children’s Respiratory and Environmental Workgroup (CREW) birth cohort consortium: design, methods, and study populationData elements common to multiple cohorts. The number of cohorts that collected each data element is shown according to maternal prenatal exposure (a) and childhood life stage (b); infancy 0–11 mo., early childhood 1–4 years, middle childhood 5–11 years, adolescence 12–18 years)Back to article page