Effects of an Intervention App on Problematic Smartphone Use: Randomized Controlled Trial (Preprint)
BACKGROUND People spend large parts of their everyday life using their smartphone. Despite various advantages of the smartphone for daily life, problematic forms of smartphone use exist which are related to negative psychological and physiological consequences. To reduce problematic smartphone use, existing interventions are oftentimes app-based and include components, that help users to monitor and restrict their smartphone use by setting timers and blockers. Such digital detox interventions lack to address psychological resources such as promoting a self-efficacious and goal-directed smartphone use. OBJECTIVE Evaluation of the theory-based smartphone app “not less but better” that was developed to make people aware of psychological processes while using the smartphone and to support them in using their smartphone in accordance with their goals and values. METHODS In a randomized controlled trial with 232 participants, effects of a 20-day intervention app consisting of five 4-days training modules to foster a goal-directed smartphone use were evaluated. In the active control condition (treatment-as-usual), participants received a digital detox treatment and planned daily timeouts of at least one hour per day. Up to a 3-weeks follow-up, self-reported problematic smartphone use, objectively measured daily smartphone unlocks, time of smartphone use, self-efficacy, and planning towards goal-directed smartphone use were assessed repeatedly. Linear two-level models tested intervention effects. Mediation models were used to analyse mechanisms of the intervention. RESULTS Both conditions manifested substantial reductions in their problematic smartphone use as well as in the amount of time spent with the smartphone. These reductions were documented at postintervention and remained stable at the 3-weeks follow-up. The number of daily unlocks did not change over time. Further, modelling changes in self-efficacy as a mediator between the intervention and problematic smartphone use at follow-up fitted well to the data and showed an indirect effect (b=-0.09 (CIBC 95% [-0.26, -0.01]), indicating that self-efficacy was an important intervention mechanism. Another mediation model revealed an indirect effect from changes in planning via smartphone unlocks at postintervention on problematic smartphone use at follow-up (b=-0.029, CIBC 95% [-0.078, -0.003]). CONCLUSIONS An innovative, theory-based intervention app on goal-directed smartphone use has been found useful in lowering problematic smartphone use as well as time spent with the smartphone. As the active control condition (planning of daily timeouts) experienced similar reductions in these two outcomes, a combined version of both experimental conditions could be used in future interventions on smartphone behaviours. Moreover, present findings highlight the importance to promote psychological resources such as self-efficacy and planning of goal-directed smartphone use to achieve improvements in problematic smartphone use. CLINICALTRIAL German Clinical Trials Register; https://drks.de/drks_web/setLocale_EN.do; identifier: DRKS00017606