title: Validity of the Bouchard activity diary in Spanish adolescents.
abstract: OBJECTIVE
  Valid and simple instruments to assess physical activity (PA) in specific populations are required for health-related research. The aim of the present study was to assess the validity of the Bouchard activity diary (AD) in Spanish adolescents using an activity monitor to compare total PA and moderate-to-vigorous PA (MVPA) obtained by both instruments.
  
  
  METHODS
  Sixty-one Spanish adolescents, aged 12-16 years, completed the Bouchard AD and wore the ActiGraph activity monitor for three consecutive days. Validity was assessed with the Spearman correlation coefficient (rho), the Bland-Altman method and the kappa coefficient.
  
  
  RESULTS
  Thirty-seven adolescents were included in the final analysis. Correlations between the activity monitor and the AD administered over the three days (Thursday-Saturday) were moderate (rho = 0.33-0.35, P < 0.05) or non-significant for total PA and moderate (rho = 0.36, P < 0.05) for MVPA. Correlations between the two methods were progressively lower for each subsequent day of testing, for both total PA and MVPA. The Bland-Altman plot illustrated that the Bouchard AD overestimated MVPA (mean difference -32.05 (sd 74.56) min; 95 % limits of agreement 109.61, -173.31 min). Agreements for classification into MVPA tertiles and accordance with the international recommendations of MVPA were fair and moderate, respectively, for the 3 d means.
  
  
  CONCLUSIONS
  The Bouchard AD has reasonable validity to assess total PA and MVPA in Spanish adolescents. The results show lower levels of agreement on the third day but it is not clear if this is due to design features (weekday v. weekend) or to participant compliance with the survey or the activity monitoring protocol.
authors.affiliation: Immunonutrition Research Group, Department of Metabolism and Nutrition, Instituto del Frio, Institute of Food Science, Technology and Nutrition (ICTAN), Spanish National Research Council (CSIC), Calle José Antonio Novais 10, E-28040 Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Martínez-Gómez
authors.forename: Julia
authors.initials: J
authors.lastname: Wärnberg
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Welk
authors.forename: Michael
authors.initials: M
authors.lastname: Sjöström
authors.forename: Oscar L
authors.initials: OL
authors.lastname: Veiga
authors.forename: Ascension
authors.initials: A
authors.lastname: Marcos
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic; D009043:Motor Activity; D050177:Overweight / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D010349:Patient Compliance; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013030:Spain; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires / Q000592:standards*; D013997:Time Factors