title: Quantification of physical activity using the QAPACE questionnaire: A two stage cluster sample design survey of children and adolescents attending urban school.
abstract: BACKGROUND
  Quantification of physical activity as energy expenditure is important since youth for the prevention of chronic non communicable diseases in adulthood. It is necessary to quantify physical activity expressed in daily energy expenditure (DEE) in school children and adolescents between 8-16 years, by age, gender and socioeconomic level (SEL) in Bogotá.
  
  
  METHODS
  This is a Two Stage Cluster Survey Sample. From a universe of 4700 schools and 760000 students from three existing socioeconomic levels in Bogotá (low, medium and high). The random sample was 20 schools and 1840 students (904 boys and 936 girls). Foreshadowing desertion of participants and inconsistency in the questionnaire responses, the sample size was increased. Thus, six individuals of each gender for each of the nine age groups were selected, resulting in a total sample of 2160 individuals. Selected students filled the QAPACE questionnaire under supervision. The data was analyzed comparing means with multivariate general linear model. Fixed factors used were: gender (boys and girls), age (8 to 16 years old) and tri-strata SEL (low, medium and high); as independent variables were assessed: height, weight, leisure time, expressed in hours/day and dependent variable: daily energy expenditure DEE (kJ.kg-1.day-1): during leisure time (DEE-LT), during school time (DEE-ST), during vacation time (DEE-VT), and total mean DEE per year (DEEm-TY) RESULTS: Differences in DEE by gender, in boys, LT and all DEE, with the SEL all variables were significant; but age-SEL was only significant in DEE-VT. In girls, with the SEL all variables were significant. The Post-hoc multiple comparisons tests were significant with age using Fisher's Least Significant Difference (LSD) test in all variables. For both genders and for all SELs the values in girls had the higher value except SEL high (5-6) The boys have higher values in DEE-LT, DEE-ST, DEE-VT; except in DEEm-TY in SEL (5-6) In SEL (5-6) all DEEs for both genders are highest. For SEL (3-4) all DEEs are lowest.
  
  
  CONCLUSIONS
  Children and adolescents in Bogotá have less DEE than at other latitudes. Girls have more free time but lower energy expenditure in their different activities. The socioeconomic level has influence in DEE.
authors.affiliation: Sports Medicine Program, El Bosque University, Bogotá, Colombia - nicobarbosadiaz@gmail.com.
authors.forename: N
authors.initials: N
authors.lastname: Barbosa
authors.forename: C E
authors.initials: CE
authors.lastname: Sanchez
authors.forename: E
authors.initials: E
authors.lastname: Patiño
authors.forename: B
authors.initials: B
authors.lastname: Lozano
authors.forename: J
authors.initials: J
authors.lastname: Thalabard
authors.forename: S
authors.initials: S
authors.lastname: Le Bozec
authors.forename: M
authors.initials: M
authors.lastname: Rieu