Research

International Physical Activity Questionnaire (IPAQ) and New Zealand Physical Activity Questionnaire (NZPAQ): A doubly labelled water validation

Ralph Maddison¹ , Cliona Ni Mhurchu^{* 1} , Yannan Jiang^{* 1} , Stephen Vander Hoorn^{* 1} , Anthony Rodgers^{* 1} , Carlene MM Lawes^{* 1} and Elaine Rush^{* 2}

¹Clinical Trials Research Unit, University of Auckland, Auckland, New Zealand

²Centre for Physical Activity and Nutrition, Auckland University of Technology, Auckland, New Zealand

author email corresponding author email* Contributed equally

International Journal of Behavioral Nutrition and Physical Activity 2007, 4:62doi:10.1186/1479-5868-4-62

Published:	3 December 2007

Abstract

Background

Accurate measurement of physical activity is a pre-requisite for monitoring population health and for evaluating effective interventions. The International Physical Activity Questionnaire (IPAQ) is used as a comparable and standardised self-report measure of habitual physical activity of populations from different countries and socio-cultural contexts. The IPAQ has been modified to produce a New Zealand physical activity questionnaire (NZPAQ). The aim of this study was to validate the IPAQ and NZPAQ against doubly labelled water (DLW). Method: Total energy expenditure (TEE) was measured over a 15-day period using DLW. Activity-related energy expenditure (AEE) was estimated by subtracting the energy expenditure from resting metabolic rate and thermic effect of feeding from TEE. The IPAQ (long form) and NZPAQ (short form) were completed at the end of each 7-day period. Activity-related energy expenditure (IPAQ_AEE and NZPAQ_AEE) was calculated from each questionnaire and compared to DLW_AEE.

Results

Thirty six adults aged 18 to 56 years (56% female) completed all measurements. Compared to DLW_AEE, IPAQ_AEE and NZPAQ_AEE on average underestimated energy expenditure by 27% and 59%, respectively. There was good agreement between DLW_AEE and both IPAQ_AEE and NZPAQ_AEE at lower levels of physical activity. However there was marked underestimation of questionnaire-derived energy expenditure at higher levels of activity.

Conclusion

Both the IPAQ and NZPAQ instruments have a demonstrated systematic bias toward underestimation of physical activity-related energy expenditure at higher levels of physical activity compared to DLW. Appropriate calibration factors could be used to correct for measurement error in physical activity questionnaires and hence improve estimation of AEE.