title: [Validity and reproducibility of a physical activity questionnaire for adolescents: adapting the Self-Administered Physical Activity Checklist].
abstract: OBJECTIVE
  To evaluate test-retest reproducibility and the validity of a physical activity questionnaire for adolescents (adapted from Self-Administered Physical Activity Checklist).
  
  
  METHODS
  The test-retest reproducibility analysis was completed by 239 adolescents (average age 16 years, SD = 1.2; 56.4% female), and the validity analysis by 70 adolescents (average age 15.7 years, SD = 1.2; 55.7% female). All adolescents were high school students in João Pessoa, PB, in Northeastern Brazil, in 2009. The test-retest reproducibility was determined by repeated evaluations with one week interval between them. Validity of the physical activity questionnaire was assessed by comparing the results of the questionnaire with those of four 24-hour recalls (reference method).
  
  
  RESULTS
  The test-retest reproducibility was high (intraclass correlation coefficient: ICC = 0.88; 95%CI: 0.84 - 0.91), and the agreement was moderate for physical activity classified in two groups (< 300 min/week vs. > 300 min/week; kappa coefficient: k = 0.52). Spearman correlation coefficient comparing the questionnaire data with those of four 24-hour recalls (reference method) was moderate (rho = 0.62; p < 0001). The agreement between these measures (questionnaire and 24-hours recalls) for physical activity classified in two groups was moderate (k = 0.59).
  
  
  CONCLUSIONS
  The physical activity questionnaire showed high reproducibility, and moderate validity, and therefore, its use is recommended for assessing adolescents' physical activity level.
authors.affiliation: Grupo de Estudos e Pesquisas em Epidemiologia da Atividade Física, CCS, Departamento de Educação Física, Universidade Federal da Paraíba. jcazuzajr@hotmail.com
authors.forename: José Cazuza
authors.initials: JC
authors.lastname: de Farias
authors.forename: Adair da Silva
authors.initials: Ada S
authors.lastname: Lopes
authors.forename: Jorge
authors.initials: J
authors.lastname: Mota
authors.forename: Maria Paula
authors.initials: MP
authors.lastname: Santos
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Ribeiro
authors.forename: Pedro Curi
authors.initials: PC
authors.lastname: Hallal
mesh_terms: D000293:Adolescent; D057189:Checklist; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult