title: Validity and reliability of a physical activity social support assessment scale.
abstract: OBJECTIVE
  To assess the validity and reliability of the Brazilian version of the physical activity social support scale for adults.
  
  
  METHODS
  The scale was applied in conjunction with a face-to-face multi-dimensional questionnaire in 1,461 individuals aged between 18 and 79 years, living in Curitiba, Southeastern Brazil, between April and July 2009. The questionnaire was submitted to validity (factorial and construct) and reliability testing (internal consistency and reproducibility). Reliability was observed with the use of internal consistency, Cronbach's alpha, test-retest procedure with a one-week interval (n = 74) and intraclass correlation coefficient.
  
  
  RESULTS
  Factorial analysis resulted in four factors with eigenvalues between 4.29 and 1.39, which explained 82.8% of the total variance. Factors 1 and 2 included questions about social support from friends for moderate to vigorous physical activities and walking, respectively. Factors 3 and 4 were comprised of groups of social support from the family for moderate to vigorous physical activities and walking, respectively. Reproducibility showed an intraclass correlation coefficient between 0.63 and 0.80 and alpha internal consistency between 0.87 and 0.91. Construct validity was observed from the significant association (p < 0.005) between scores of social support for walking and moderate to vigorous physical activities.
  
  
  CONCLUSIONS
  The instrument tested showed psychometric characteristics that were adequate for use in adult Brazilians.
authors.affiliation: Grupo de Pesquisa em Atividade Física e Qualidade de Vida, Centro de Ciências Biológicas e da Saúde, Pontifícia Universidade Católica do Paraná, R. Imaculada Conceição 1155, Curitiba, PR, Brazil. marianass@pop.com.br
authors.forename: Mariana Silva dos
authors.initials: MS
authors.lastname: Reis
authors.forename: Rodrigo Siqueira
authors.initials: RS
authors.lastname: Reis
authors.forename: Pedro Curi
authors.initials: PC
authors.lastname: Hallal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D015203:Reproducibility of Results; D012944:Social Support; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult