Intervention to reduce recreational screen-time in adolescents: Outcomes and mediators from the ‘Switch-Off 4 Healthy Minds’ (S4HM) cluster randomized controlled trial

Highlights

• Reductions in screen-time were not statistically significant.

• No intervention effects were found for mental health, physical activity or BMI.

• Intervention effect was partially mediated by increases in autonomous motivation.

Abstract

Introduction

The primary objective was to evaluate the impact of the ‘Switch-off 4 Healthy Minds’ (S4HM) intervention on recreational screen-time in adolescents.

Methods

Cluster randomized controlled trial with study measures at baseline and 6-months (post-intervention). Eligible participants reported exceeding recreational screen-time recommendations (i.e., > 2 h/day). In total, 322 adolescents (mean age = 14.4 ± 0.6 years) from eight secondary schools in New South Wales, Australia were recruited. The S4HM intervention was guided by Self-Determination Theory and included: an interactive seminar, eHealth messaging, a behavioral contract and parental newsletters. The primary outcome was recreational screen-time. Secondary outcomes included mental health (i.e., well-being, psychological distress, self-perceptions), objectively measured physical activity, and body mass index (BMI). Outcome analyses were conducted using linear mixed models and mediation was examined using a product-of-coefficients test.

Results

At post-intervention, significant reductions in screen-time were observed in both groups, with a greater reduction observed in the intervention group (− 50 min/day versus − 29 min, p < 0.05 for both). However, the adjusted difference in change between groups was not statistically significant (mean = − 21.3 min/day, p = 0.255). There were no significant intervention effects for mental health outcomes, physical activity or BMI. Significant mediation effects for autonomous motivation were found.

Conclusions

Participants in both the S4HM intervention and control groups significantly reduced their screen-time, with no group-by-time effects. Enhancing autonomous motivation might be a useful intervention target for trials aimed at reducing adolescents' recreational screen-time.

Trial registration

ACTRN12614000163606.

Introduction

Excessive recreational screen-time is associated with numerous adverse physical (Escobar-Chaves et al., 2010, Tremblay et al., 2011) and mental health (Tremblay et al., 2010, Strasburger et al., 2010) outcomes in youth. Despite international guidelines recommending young people limit their recreational screen-time to < 2 h/day (Mark and Janssen, 2008), between 70 and 80% of Western youth exceed these recommendations (Mark et al., 2006, Owens et al., 2013, Morley et al., 2012). As excessive screen-time is a major public health issue in many Western countries, there is a need for scalable interventions that can reach a large proportion of the youth population. According to a recent meta-analysis of screen-time interventions, home-based interventions have been more successful than those conducted in schools (Marsh et al., 2014). However, few of the included studies targeted adolescents, and it is therefore unclear which intervention approaches are most effective for this priority population. While parental involvement is considered an important determinant of success in youth screen-time interventions (Marsh et al., 2014), engaging parents in such interventions remains challenging (Ingoldsby, 2010). Schools have the facilities and personnel to support the implementation of interventions (Hills et al., 2015), but may also have value as an avenue for accessing and engaging parents. Indeed, embedding health promotion interventions within schools may give health promotion programs the exposure and credibility needed to convince parents to participate. Moreover, there is a rationale for evaluating interventions that meaningfully incorporate parental engagement within school-based programs.

Evidence suggests theory-based screen-time interventions have been more effective than those that do not report a theoretical framework (Maniccia et al., 2011). Therefore, an additional priority for interventions should be the application of behavioral theories, and the evaluation of theoretical mediators of behavior change. Self-determination theory (SDT) is a motivational theory which posits that human motivation and behavior are influenced by the satisfaction (or thwarting) of individuals' basic psychological needs for autonomy (sense of choice or volition), competence (sense of capability or mastery) and relatedness (sense of connectedness with others) (Ryan and Deci, 2007). According to SDT, satisfaction of these psychological needs will promote autonomous (or self-determined) forms of motivation. Autonomous motivation reflects more ‘internalized’ reasons for engaging in (or avoiding) a behavior. For example, an individual may decide to maintain an active lifestyle or limit their alcohol consumption due to the perceived health or social benefits. Autonomous motives are considered to be more strongly related to behavioral enactment than controlled motives, which involve engaging in or changing behavior on the basis of external demands or social pressures (Ryan and Deci, 2007). Accordingly, behavior change strategies that enable individuals to feel their decisions are self-endorsed (rather than imposed) should result in a greater likelihood of initial behavior change and ongoing behavior maintenance (Ryan and Deci, 2000).

The aim of the present study is to evaluate the efficacy of the ‘Switch-off 4 Healthy Minds’ (S4HM) intervention, a novel and theoretically based screen-time intervention for adolescents. We hypothesize that adolescents in the S4HM intervention will report significantly lower levels of recreational screen-time at 6-month post-intervention, compared to those in a wait-list control group. In addition, we hypothesize that changes in screen-time over the study period will be mediated by changes in adolescents' autonomous motivation to limit their screen-time.