Text messaging interventions for improvement in physical activity and sedentary behaviour in youth: systematic review

Background
The use of text messages (SMS) to change physical activity (PA) and sedentary behaviour (SB) in youth is of interest due to the need for novel, more effective intervention approaches. Previous reviews have examined a variety of technology-based interventions and their impact on different health behaviours but evidence regarding the impact of just SMS on PA and SB is lacking. Thus, the current systematic review aims to assess the effectiveness of SMS interventions for improving PA and SB in youth.

Methods
Authors systematically searched electronic databases from March to November 2017. Citations were sifted using additional reviewers and a qualitative synthesis of eligible studies was conducted using piloted data extraction forms. To be eligible for inclusion, studies had to be of randomised controlled or quasi-experimental design, incorporate SMS, involve adolescents between the ages of 10 and 19 and assess at least one PA or SB outcome. Risk of bias was assessed using the Cochrane Collaboration’s Risk of Bias tool.

Results
Thirteen studies reporting on 11 interventions were included in the qualitative synthesis. Studies included interventions that were conducted in schools, online or face-to-face. Studies were of high heterogeneity with regards to study duration, participant characteristics, intervention content and outcome measures. Findings were equivocal with regards to intervention effectiveness for PA and SB. 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
Some studies in this review showed promising results for using SMS to improve PA and SB in youth. High heterogeneity of design and outcome measures precluded data pooling and conclusions as to which specific intervention elements are linked to increased effectiveness cannot be drawn. The authors propose incorporating the following elements in future studies: specific focus on desired health behaviour; mixed methods design; include long-term follow-up; include self-monitoring, goal setting and feedback; combine SMS with a mobile app; send 3 or more SMS per week. More rigorous studies are needed to explore the relationship between intervention effectiveness and specific intervention components such as content and delivery.