Validation of the New Zealand Physical Activity Questionnaire (NZPAQ-LF) and the International Physical Activity Questionnaire (IPAQ-LF) with Accelerometry

Background Validation of instruments used to measure physical activity patterns are essential when attempting to assess the effectiveness of physical activity interventions.

Objectives To assess the validity of two self-report physical activity questionnaires on a representative sample of New Zealand adults.

Methods Seventy adults aged 18-65 years from around Christchurch, New Zealand were required to wear an ActiGraph GT1M accelerometer during all waking hours for seven consecutive days. Immediately following the 7-day accelerometer period participants were required to complete the long forms of both the New Zealand Physical Activity Questionnaire (NZPAQ-LF) and the International Physical Activity Questionnaire (IPAQ-LF).

Results Both the NZPAQ-LF and the IPAQ-LF questionnaires showed small to moderate correlations to Actigraph data for time spent in moderate-intensity physical activity (r = 0.19 – 0.30), and total physical activity (sum of moderate and vigorous-intensity physical activity r = 0.30 – 0.32). Compared to the Actigraph data both self-report questionnaires tended to overestimate activity levels by ~ 165%. Total physical activity levels gathered from both questionnaires were strongly correlated to each other (r = 0.79) and showed good levels of agreement in the Bland-Altman plots.

Conclusions We found the long forms of the NZPAQ and IPAQ had acceptable validity when detecting participant’s ability to meet activity guidelines based on exercise duration, but a significant amount of over-estimation was evident. This presents a need for both instruments to be further developed and tested in order to increase validity.

Link to Abstract: http://www.ncbi.nlm.nih.gov/pubmed/18981036