Abstract:
Background: Although physical activity is recognised to be an important determinant of health
and nutritional status, few instruments have been developed to assess physical activity in developing
countries. The aim of this study was to compare the validity of the short form of the International
Physical Activity Questionnaire (IPAQ) and a locally adapted version of the Physical Activity
Questionnaire for Adolescents (PAQA) for use in school going adolescents in rural and urban areas
in Vietnam.
Methods: Sixteen year old adolescents from rural areas (n = 137) and urban areas (n = 90)
completed the questionnaires in 2006. Test-retest reliability was assessed by comparing
registrations after 2 weeks. Criterion validity was assessed by comparison with 7 days continuous
accelerometer logging. Validity of the two methods was assessed using Spearman correlation
coefficient, intra class correlation coefficients (ICC) and Kappa statistics.
Results: Reliability of both questionnaires was poor for both the IPAQ (ICC = 0.37) and the PAQA
(ICC = 0.40). Criterion validity of both questionnaires was acceptable and similar for the IPAQ (ρ
= 0.21) and the PAQA (ρ = 0.27) but a significantly lower validity was observed in rural areas. Both
forms poorly estimated time spent on light, moderate and vigorous physical activity. Agreement of
both questionnaires to classify individuals was also low but the IPAQ performed better than the
PAQA.
Conclusion: Both questionnaires have a similar and overall poor validity to be used as a population
instrument in Vietnam. Low reliability and classification properties in rural areas call for further
research for specific use in such settings.
