title: Nesting sub-studies and randomised controlled trials within birth cohort studies.
abstract: Although birth cohort studies can stand on their own, there are a number of different types of sub-studies that can add value to the overall project. These can be summarised within four main categories: (A) more detailed observations of relatively small subgroups aimed at describing mechanisms and processes; (B) nested case-control studies; (C) use of detailed observations to validate data collection by questionnaire or interview; (D) randomised controlled trials. For each category we give examples of ways in which they have been employed in current pregnancy birth cohort studies.
authors.affiliation: Centre for Child and Adolescent Health, Department of Community Based Medicine, University of Bristol, Bristol, UK. jean.golding@bristol.ac.uk
authors.forename: Jean
authors.initials: J
authors.lastname: Golding
mesh_terms: D016022:Case-Control Studies; D002649:Child Abuse / Q000517:prevention & control; D015331:Cohort Studies; D003625:Data Collection / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D016487:Parenting; D010290:Parents / Q000523:psychology; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic