Related Experiment Video
Updated: Aug 20, 2026
Measuring Cardiac Autonomic Nervous System (ANS) Activity in Toddlers - Resting and Developmental Challenges
Published on: February 25, 2016
Comparison of Actiwatch activity monitor and Children's Activity Rating Scale in children
1School of HPELS, University of Northern Iowa, Cedar Falls 50614-0241, USA. kevin.finn@uni.edu
Insights
Activity monitors, like the Actiwatch, effectively assess physical activity in preschool children, correlating well with the Children's Activity Rating Scale (CARS) observations. This suggests monitors are a viable alternative to direct observation methods.
Area of Science:
- Pediatric physical activity assessment
- Biomedical engineering
- Observational research methods
Background:
- Direct observation using the Children's Activity Rating Scale (CARS) is a common method for assessing physical activity in children.
- However, direct observation is resource-intensive and its accuracy may decline with longer observation periods.
- Motion sensors are increasingly accepted as a valid tool for physical activity assessment.
Purpose of the Study:
- To compare the assessment of physical activity levels in preschool-aged children over a 6-hour period using simultaneous monitoring with CARS and the Actiwatch activity monitor.
- To evaluate the correlation between CARS scores and activity counts from the Actiwatch.
Main Methods:
- Forty preschool-aged children participated in the study, with 5-6 hours of simultaneous direct observation (CARS) and Actiwatch monitoring.
- Data were collected in 3-minute intervals, matching CARS scores with corresponding activity counts from the Actiwatch.
- Statistical analysis involved correlating 3-minute CARS scores with 3-minute activity counts.
Main Results:
- A significant positive correlation was found between 3-minute CARS scores and 3-minute activity counts (median r=0.74, P < 0.001).
- Correlations were stronger in more active children, likely due to wider variations in CARS scores.
- Actiwatch sensor readings were significantly associated with CARS scores.
Conclusions:
- The 3-minute CARS score demonstrates a strong correlation with 3-minute activity counts obtained from the Actiwatch.
- Activity monitors are a feasible and effective tool for assessing physical activity in preschool-aged children.
- This supports the use of activity monitors as a more efficient alternative to direct observation.
Purpose:
The Children's Activity Rating Scale (CARS) is a rating scale that is used in direct observation of physical activity in children. Direct observation is costly and tedious, and accuracy may decrease as the observation period lengthens. Recently, motion sensors have gained acceptance for assessment of physical activity. The purpose of this study was to compare 6 h of activity levels using simultaneous monitoring of preschool aged children with CARS and the Actiwatch (Mini-mitter Company Inc.) activity monitor.
Methods:
A total of 40 children had 5-6 h (mean of 5.9 h) of direct observation while wearing a monitor on the waist. Simultaneous 3-min mean CARS scores and 3-min activity counts were matched for each subject.
Results:
The range for the mean 3-min CARS scores ranged from 1.00 to 4.50. The 3-min activity counts ranged from 0 to 9,695 with a mean of 670 (median 243). The within child correlations between the 3-min CARS score and the 3-min sensor readings ranged from 0.03 to 0.92 (median of 0.74). We found the correlation coefficients were higher in those children who were more active, probably due to the larger ranges in the CARS scores. When using mixed model repeated measures, sensor readings were significantly associated with CARS (P < 0.001).
Conclusion:
Our results indicate that the 3-min CARS score correlates with 3-min activity counts, favoring the use of the activity monitors in assessing physical activity in preschool-aged children.
