Calibration of context-specific survey items to assess youth physical activity behaviour.
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.
a Department of Kinesiology , Iowa State University , Ames , IA , USA.|b School of Psychology, CIPsi , University of Minho , Braga , Portugal.
Pedro F
PF
Saint-Maurice
a Department of Kinesiology , Iowa State University , Ames , IA , USA.
Gregory J
GJ
Welk
c Human Performance Lab , University of Nebraska at Kearney , Kearney , NE , USA.
R Todd
RT
Bartee
c Human Performance Lab , University of Nebraska at Kearney , Kearney , NE , USA.
Kate
K
Heelan
D056044:Actigraphy; D000293:Adolescent; D002648:Child; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D012574:Schools; D011795:Surveys and Questionnaires; D013997:Time Factors
MVPA; home; measurement; school; youth