TITLE:
Comparison of activity levels measured by a wrist worn accelerometer and direct observation in young children
AUTHORS:
Kurosh Djafarian, John R. Speakman, Joanne Stewart, Diane M. Jackson
KEYWORDS:
Accelerometer; Physical Activity; Children; Observation
JOURNAL NAME:
Open Journal of Pediatrics,
Vol.3 No.4,
December
20,
2013
ABSTRACT: Introduction: Motion sensors are mechanical and
electronic devices, which detect the body movement and provide an estimate of
physical activity in children and adults. However, they need to be validated
against criterion methods such as direct observation. The purpose of this study
was to validate a wrist worn accelerometer to quantify the physical activity of
children, by comparison to direct observation using the Children’s Activity
Rating Scale (CARS). Materials and Methods: Data were recorded from 42
children, aged 3 - 5 years (22 boys and 20 girls), of whom each was observed
each minute for 2 hours using Children’s Activity Rating Scale (CARS) while
they wore the Actiwatch. Results: The CARS score and activity counts from the
accelerometer were averaged over 1- to 10-minute periods across all individuals.
There was a significant positive correlation between the mean CARS scores and
the mean Actiwatch counts over simultaneous 1- to 10-minute periods ranging
from r = 0.41 to r = 0.63 (P tween the predicted and the observed CARS scores in
the validation sample. Given the data from the Actiwatch (averaged over a
5-minute epoch), the equivalent CARS score could be calculated with a 95% confidence
level of plus or minus 0.74 CARS units. Conclusion: These data suggest that the
Actiwatch (a wrist worn accelerometer) is a valid tool for assessing levels of
physical activity in young children.