title: [Methodological description of accelerometry for measuring physical activity in the 1993 and 2004 Pelotas (Brazil) birth cohorts].
abstract: The aim of this study was to characterize the methodology of data collection on physical activity using accelerometry in two birth cohorts (2004 and 1993) in Pelotas, Rio Grande do Sul State, Brazil, at the 6-7 and 18-year follow-up visits, respectively. During visits to the study headquarters for a health evaluation, cohort subjects received the accelerometer to be worn on the wrist for 5 to 8 days, after which the device was retrieved at their homes. Genea and GENEActiv triaxial estimators of gravity (g) acceleration were employed. Accelerometry data were collected from 3,331 children (93.7% of those included in follow-up) and 3,816 adolescents (99% of those in follow-up). The study characterizes the data collection methodology in more than 7,000 individuals and discusses issues in its implementation. It thus provides a methodological framework aimed at helping to plan future population-based studies with the use of such technology and to improve understanding of physical activity in the context of epidemiological studies.
authors.affiliation: Universidade Federal do Rio Grande, Rio Grande, Brasil. alan_knuth@yahoo.com.br
authors.forename: Alan Goularte
authors.initials: AG
authors.lastname: Knuth
authors.forename: Maria Cecília F
authors.initials: MC
authors.lastname: Assunção
authors.forename: Helen
authors.initials: H
authors.lastname: Gonçalves
authors.forename: Ana Maria B
authors.initials: AM
authors.lastname: Menezes
authors.forename: Iná S
authors.initials: IS
authors.lastname: Santos
authors.forename: Aluísio J D
authors.initials: AJ
authors.lastname: Barros
authors.forename: Alicia
authors.initials: A
authors.lastname: Matijasevich
authors.forename: Virgílio Viana
authors.initials: VV
authors.lastname: Ramires
authors.forename: Inácio Crochemore Mohnsamb da
authors.initials: IC
authors.lastname: Silva
authors.forename: Pedro Curi
authors.initials: PC
authors.lastname: Hallal
mesh_terms: D061725:Accelerometry / Q000379:methods*; D000293:Adolescent; D001938:Brazil; D002648:Child; D015331:Cohort Studies; D006801:Humans; D009043:Motor Activity / Q000502:physiology*; D011795:Surveys and Questionnaires