Background: Physical activity is essential to the long-term health of children living with cardiac disease. The simplicity and cost of pedometers make them an attractive alternative to accelerometers for monitoring the physical activity behaviors of these children. This study compared measures obtained from commercial-grade pedometers and accelerometers.
Methods: Pediatric cardiology outpatients (n = 41, mean age = 8.4 [3.7] y, 61% female) wore a pedometer and accelerometer daily for 1 week. Step counts and minutes of moderate to vigorous physical activity were compared between devices, accounting for age group, sex, and diagnostic severity, using univariate analysis of variance.
Results: While pedometer data were significantly correlated with accelerometers (r > .74, P < .001), measurements obtained were significantly different between devices. Overall, pedometers overestimated physical activity data. The overestimation of moderate to vigorous physical activity was significantly less among adolescents than younger age groups (P < .01, ηp2=.38). For step counts, there was a significant age by sex interaction observed where preschool and adolescent males tended to have greater differences between accelerometer and step count data than females (P < .01, ηp2=.33). Differences between devices were not associated with severity of diagnosis.
Conclusions: The distribution of pedometers in a pediatric outpatient clinic was feasible, yet the data collected significantly overestimated physical activity, especially among younger children. Practitioners who want to introduce objective measurements as part of their physical activity counseling practice should use pedometers to monitor individual changes in physical activity and consider patient age before administering these devices for clinical care.
Keywords: accelerometry; congenital heart disease; exercise medicine; physical activity assessment; physical activity counseling.