title: Cut-off values for classifying active children and adolescentes using the Physical Activity Questionnaire: PAQ-C and PAQ-ACut-off values for classifying active children and adolescents using the Physical Activity Questionnaire: PAQ-C and PAQ-A.
abstract: BACKGROUND
  The Physical Activity Questionnaire for children and adolescents (PAQ-C & PAQ-A) has been widely used in research and field settings. However, there is a lack of information about its final score meaning.
  
  
  OBJECTIVE
  To determine PAQ-C and PAQ-A score cut-off values using physical activity (PA) thresholds objectively measured as reference criteria.
  
  
  METHODS
  146 children (n = 83 boys, n = 63 girls) and 234 adolescents (n = 115 boys, n = 119 girls) participated in this study. Accelerometers (Actigraph GT3X) were used to assess objectively PA during one-week, afterwards PAQ was filled by the participants. As participants met or not the international PA recommendations for total, moderate-vigorous (MVPA) or light PA, three categorical variables of two levels were created. ROC curves procedure were carried out to obtain score cut-off points for identifying the positive category recommendation.
  
  
  RESULTS
  ROC curves analysis estimated 2.75 and 2.73 score cut-off points to discriminate > 60 minutes of MVPA for PAQ-A and PAQ-C respectively (PAQ-A AUC = 0.68, p < 0.001 and PAQ-C; AUC = 0.55, p > 0.05). Also 60 minutes of MVPA was achieved with a total volume of 10,664 steps/day in children and 9,701 steps/day in adolescents.
  
  
  CONCLUSIONS
  Our results suggest that PAQ-A can be a useful tool to classify adolescents as active or inactive following international recommendations as criteria. However, we could not find a significant cut-off for PAQ-C score.
authors.affiliation: Biodynamic and Body Composition Laboratory. Universidad de Málaga. Málaga. benitez@uma.es.
authors.forename: Javier
authors.initials: J
authors.lastname: Benítez-Porres
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Alvero-Cruz
authors.forename: Luis B
authors.initials: LB
authors.lastname: Sardinha
authors.forename: Iván
authors.initials: I
authors.lastname: López-Fernández
authors.forename: Elvis A
authors.initials: EA
authors.lastname: Carnero
mesh_terms: D000293:Adolescent; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D011795:Surveys and Questionnaires
keywords: ROC curves.  Adolescence.  Childhood. Sensitivity.  Specificity.