ASSESSMENT OF PHYSICAL ACTIVITY IN SCHOOLCHILDREN USING A WEB-BASED QUESTIONNAIRE

ABSTRACT

Introduction:

Physical activity is a behavior that is established during childhood and tends to be maintained in adulthood, influencing the regulation of the energy balance, weight and body fat, and thereby preventing obesity. Therefore, creating and validating methods to assess and monitor this activity in children and adolescents across the whole population is very important for guiding public health policies.

Objective:

To assess the validity and reproducibility of self-reported sedentary behaviors and physical activity, through the web-based Questionnaire Consumo Alimentar e Atividade Física de Escolares (Web-CAAFE, Food Intake and Physical Activity of School Children).

Methods:

^{_{Students in the 2nd to 5th grades (n = 390) were directly observed during break times, and were asked to fill out the Web-CAAFE questionnaire the day after. A subsample (n = 94) completed the Web-CAAFE twice, with an interval of three hours between each time. The energy cost was calculated for each physical activity as metabolic equivalents (MET) and added to the individual level. The individual MET for the physical activities and total self-reported sedentary behaviors were the main outcomes, analyzed separately by Poisson regression and hierarchical Poisson regression (student as the first level and repetition of the methods in the second level). The results were presented as Incidence Ratios (IR). The residuals were analyzed graphically by gender and age.}}

Results:

The Web-CAAFE overestimated the total sedentary behaviors (IR=2.90, CI 95%: 2.05-4.10), especially among younger girls (7-10 years old), while for the older girls (11-15 years old), it tended to underestimation. The overestimation of MET for physical activity was lower, and was not statistically significant. No statistically significant difference was found between the first and second self-reported questionnaires, either for total sedentary behaviors or MET for physical activity.

Conclusion:

The Web-CAAFE showed good reliability and high precision when applied to the assessment of MET for physical activity in the older students.

Keywords:
validity of tests; reproducibility of results; motor activity; students