What do participants in a birth cohort study know about their homes?

Interest in the influence of indoor environments on health remains strong. However, tools designed to capture highly dimensional data on built environments are scarce (Rosenthal, 2011). The Canadian Healthy Infant Longitudinal Development (CHILD) Study employed two home environment questionnaires, one for parents and one for trained researchers, to collect information about participant homes. The questionnaires were designed to gather information about home features such as overall structure, materials, moisture issues, and occupant behaviours. We validated portions of the parent-completed questionnaire using a new method of question selection and traditional agreement statistics (percent agreement, kappa statistic, 2´2 tables). The process highlighted statistical and conceptual challenges related to questionnaire validation, and support for a new method of selecting questions for validation.