To compare physical activity measured by accelerometry at 7-10 years in children born preterm with a term-born control group.
This is a long-term follow up at 7-10 years of age of a Norwegian multicentre randomized controlled trial of parent administrated early physiotherapy for children born 32 weeks of gestation (n=92). A term-born control group (n=83) was recruited from regular schools. Physical activity was measured over a 7-day period using two tri-axial accelerometers, placed at the lower back and mid-thigh. The performed activities were classified using a machine learning based human activity recognition model. We compared time spent in activity (standing, walking, running, jumping or cycling), time spent in inactivity (lying or sitting), and number of transitions between activity and inactivity for weekdays and weekend days separately. Additional measurements included 2 Minute Walk Test and grip strength by a handhold dynamometer. Data were analysed using linear regression with bootstrapping, adjusted for age and sex.
Mean differences per day in time spent in activity between the preterm and the control group was -20.2 (95% CI: -52.6 to 10.8) minutes during weekdays and 1.1 (95% CI: -35.9 to 40.1) minutes during weekend days. Mean difference in number of transitions between activity and inactivity was 14.3 (95% CI: -55.3 to 83.2) during weekdays and 29.3 (95% CI: -32.5 to 92.6) during weekend days. When we analysed the seven activities separately, the preterm group spent 15.4 (95% CI: 3.6 to 27.1) minutes less time walking per day compared with the control group during weekdays, but this difference was reduced to -5.0 (95% CI: -17.5 to 7.8) minutes during weekend days. The mean difference between the preterm and the control group in walking distance was -10.4 (95% CI: -26.5 to 12.2) meters and in grip strength dominant hand was -0.7 (95% CI: -1.6 to 0.2) kg.
We found that the children born preterm spent less time in walking and in activity during weekdays compared to the controls. There were no differences in walking distance or grip strength, and no difference in time spent in activity during weekends.
The finding that children born preterm are less physical active compared to their term born peers at 7-10 years old is important, given the increased risk of impaired physical health in children born preterm. It is important to encourage and inspire these children to continue to take part in physical activities, as they are at risk of becoming less physical active and of falling out of sports activity as they grow older.
physical activity
accelerometer