title: Sampling: how to select participants in my research study?
abstract: BACKGROUND
  In this paper, the basic elements related to the selection of participants for a health research are discussed. Sample representativeness, sample frame, types of sampling, as well as the impact that non-respondents may have on results of a study are described. The whole discussion is supported by practical examples to facilitate the reader's understanding.
  
  
  OBJECTIVE
  To introduce readers to issues related to sampling.
authors.affiliation: Faculdade Meridional (IMED) - Passo Fundo (RS), Brazil.
authors.forename: Jeovany
authors.initials: J
authors.lastname: Martínez-Mesa
authors.affiliation: University of Adelaide - Adelaide, Australia.
authors.forename: David Alejandro
authors.initials: DA
authors.lastname: González-Chica
authors.affiliation: Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA) - Porto Alegre (RS), Brazil.
authors.forename: Rodrigo Pereira
authors.initials: RP
authors.lastname: Duquia
authors.affiliation: Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA) - Porto Alegre (RS), Brazil.
authors.forename: Renan Rangel
authors.initials: RR
authors.lastname: Bonamigo
authors.affiliation: Universidade Federal de Santa Catarina (UFSC) - Florianópolis (RS), Brazil.
authors.forename: João Luiz
authors.initials: JL
authors.lastname: Bastos
mesh_terms: D003625:Data Collection / Q000592:standards; D006801:Humans; D018579:Patient Selection; D018401:Sample Size; D012494:Sampling Studies; D015983:Selection Bias