A pilot effectiveness study of a just-in-time micro-randomized controlled trial on the physical activity and sedentary time of young children and their parents: The active family m-health intervention

TL;DR

This study tested a mobile health intervention to increase physical activity and reduce sedentary time in young children and their parents, finding limited effectiveness overall but some promise for parents over time.

Contribution

The study introduces a just-in-time micro-randomized controlled trial targeting physical activity in young children and their parents using m-health interventions.

Findings

Micro-interventions did not significantly change sedentary time, light physical activity, or moderate-to-vigorous physical activity in children or parents.

Interventions showed increased effectiveness over time in improving parents' moderate-to-vigorous physical activity.

The intervention was found to be acceptable and feasible for parents despite limited effectiveness.

Abstract

Parents play a critical role in influencing their young children’s physical activity (PA) and sedentary time (ST). Despite this, many young children (aged 3-4y) and their parents are insufficiently active and engage in high amounts of ST. M-health interventions targeting PA and ST have seldom been tested in this population. The objective of this study was to examine the effectiveness and acceptability of the Active Family m-health intervention on the PA and ST of young children and their parents.

Twenty-five stay-at-home parent-child dyads from Canada took part in the 2-week just-in-time micro-randomized controlled trial. Parents received seven text message prompts per day, where they were randomized to receive either a micro-intervention (activity suggestion) or control (no suggestion). Parents and children wore ActiGraph accelerometers to measure ST, light [LPA], and moderate-to-vigorous physical activity [MVPA]. Parents also completed a short online acceptability survey. A centred and weighted least square regression was used to analyze the effect of activity suggestions on the 60-min ST, LPA, and MVPA of parents and children following suggestion randomization. Descriptive statistics and content analysis were used to analyze acceptability survey responses.

Micro-interventions were not effective at changing children’s or parent’s proximal ST (d = 0.01, p = .878; d = −0.09, p = .485, respectively), LPA (d = 0.03, p = .714; d = 0.03, p = .729, respectively), or MVPA (d = −0.05, p = .511; d = 0.10, p = .480, respectively). Interventions became more effective at increasing MVPA over time for parents (b = 0.47, 95%CI = 0.12, 0.83, p = .013). Among children, intervention effectiveness varied by contextual factors (e.g., weather). The intervention was largely acceptable, appropriate, and feasible for parents, though they did offer suggestions for improvement.

Overall, micro-interventions did not significantly change parents or young children’s proximal movement. Though, this approach showed promise for increasing parent’s MVPA over time and for supporting children’s activity under specific conditions.

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