The effects of text-messaging interventions to improve physical activity and sedentary behaviour in youth: A systematic review

Background
The use of text messages (SMS) to change health behaviours in youth is of particular interest due to the need for novel, more effective intervention approaches. Previous reviews have examined the effect of technology-based interventions on health but evidence regarding the impact of just SMS on physical activity (PA) and sedentary behaviour (SB) is missing. Thus, this systematic review aims to assess the effectiveness of SMS interventions for improving PA and SB in youth.
Methods
Authors systematically searched electronic databases. Citations were sifted and piloted forms used for data extraction. Eligible studies had to be of randomised controlled or quasi-experimental design, incorporate SMS, participants aged between 10 and 19 and at least one PA or SB outcome. Use of theory and risk of bias were also assessed.
Results
Thirteen studies reporting on 11 interventions were eligible for inclusion. Interventions were conducted in schools, online or face-to-face. Studies were of high heterogeneity with regards to participant characteristics, intervention content and outcome measures. Findings were equivocal with regards to intervention effectiveness. Seven interventions resulted in an improvement for PA and six for SB. All studies were judged to be of high risk of bias for at least one item.
Conclusions
This review shows promising results. However, due to high heterogeneity of design and outcome measures, conclusions as to which specific intervention elements are linked to increased effectiveness cannot be drawn. More rigorous studies are needed to explore the relationship between intervention effectiveness and specific components of SMS interventions, such as message content.