Calibration of context-specific survey items to assess youth physical activity behaviour

ABSTRACT

This study tests calibration models to re-scale context-specific physical activity (PA) items to accelerometer-derived PA. A total of 195 4th–12th grades children wore an Actigraph monitor and completed the Physical Activity Questionnaire (PAQ) one week later. The relative time spent in moderate-to-vigorous PA (MVPA_%) obtained from the Actigraph at recess, PE, lunch, after-school, evening and weekend was matched with a respective item score obtained from the PAQ’s. Item scores from 145 participants were calibrated against objective MVPA_% using multiple linear regression with age, and sex as additional predictors. Predicted minutes of MVPA for school, out-of-school and total week were tested in the remaining sample (n = 50) using equivalence testing. The results showed that PAQ β-weights ranged from 0.06 (lunch) to 4.94 (PE) MVPA_% (P < 0.05) and models root mean square error ranged from 4.2% (evening) to 20.2% (recess). When applied to an independent sample, differences between PAQ and accelerometer MVPA at school and out-of-school ranged from −15.6 to +3.8 min and the PAQ was within 10–15% of accelerometer measured activity. This study demonstrated that context-specific items can be calibrated to predict minutes of MVPA in groups of youth during in- and out-of-school periods.

KEYWORDS:

• MVPA
• youth
• school
• home
• measurement

Acknowledgments

This work has been partially funded by a grant from the European Social Fund/Fundacao para a Ciencia e Tecnologia (SFRH / BD / 60396 / 2009).

Disclosure statement

The authors declare no financial interest or benefit from the applications of this research.

Additional information

Funding

This work has been partially funded by a grant from the European Social Fund/Fundacao para a Ciencia e Tecnologia [SFRH /BD /60396 /2009].

Notes on contributors

Pedro F. Saint-Maurice

P. F. Saint-Maurice performed the statistical analysis and drafted the manuscript. Gregory J. Welk participated in the design of the study and drafted the manuscript. R. Todd Bartee participated in the design of the study and coordination and helped drafted the manuscript. Kate Heelan conceived of the study, and was responsible for its design and coordination and helped drafted a manuscript. All authors approved the final manuscript.

Gregory J. Welk

P. F. Saint-Maurice performed the statistical analysis and drafted the manuscript. Gregory J. Welk participated in the design of the study and drafted the manuscript. R. Todd Bartee participated in the design of the study and coordination and helped drafted the manuscript. Kate Heelan conceived of the study, and was responsible for its design and coordination and helped drafted a manuscript. All authors approved the final manuscript.

R. Todd Bartee

P. F. Saint-Maurice performed the statistical analysis and drafted the manuscript. Gregory J. Welk participated in the design of the study and drafted the manuscript. R. Todd Bartee participated in the design of the study and coordination and helped drafted the manuscript. Kate Heelan conceived of the study, and was responsible for its design and coordination and helped drafted a manuscript. All authors approved the final manuscript.

Kate Heelan

P. F. Saint-Maurice performed the statistical analysis and drafted the manuscript. Gregory J. Welk participated in the design of the study and drafted the manuscript. R. Todd Bartee participated in the design of the study and coordination and helped drafted the manuscript. Kate Heelan conceived of the study, and was responsible for its design and coordination and helped drafted a manuscript. All authors approved the final manuscript.