ReNeuWell mental well-being app: protocol for a randomised controlled trial

The field of mental well-being interventions includes numerous studies of smartphone app-based programs, but there is a research-to-retail gap where many studies pertain to apps that are not publicly available, not used as standalone programs, or not tested in the general population, and many publicly available apps (or their proprietary in-app measures) have yet to be submitted to empirical testing. Furthermore, few well-being apps offer multicomponent interventions, despite such interventions having demonstrated efficacy outside the smartphone context. In response to these openings in the literature and marketplace, we have developed ReNeuWell, an iPhone app designed to measure the user's mental well-being (via the validated Composure, Own-worth, Mastery, Positivity, Achievement and Satisfaction for Well-being (COMPAS-W) scale) and improve their well-being via a personalised, multicomponent program of activities informed by the peer-reviewed evidence base. This article describes the protocol for the preregistered randomised controlled trial (RCT) of ReNeuWell, to test the app in adult participants from the general population of Apple App Store users. It is hypothesised that ReNeuWell users will experience significant increases in mental well-being and decreases in mental distress over the 6-12-week trial period, relative to users of an active control version of the app.

The RCT will recruit participants from Apple Store users who choose to download ReNeuWell in the normal course of browsing the marketplace. Following consent, the app will randomly allocate participants to receive either the full version of the app or the active control version. The full version assesses the user's well-being via the validated COMPAS-W scale, provides feedback on their well-being across six dimensions and creates a personalised schedule of daily positive psychology activities designed to enhance well-being along each dimension. Participants will be instructed to use the app for at least 10 min (at least one activity) per day for the first 6 weeks, and as they wish for the following 6 weeks. Trial outcomes will be measured via in-app surveys administered in weeks 1, 6 and 12. Data collection will begin when the app is officially launched on the Apple Store. Data will be analysed using linear mixed models to estimate condition-by-time interaction effects on the primary and secondary outcomes, and to assess whether any such effects are themselves moderated by other key variables.

This protocol has been approved by the Human Research Ethics Committee of the University of New South Wales (reference number: HC210302). Trial outcomes will be published in accordance with the preregistered protocol described here, both in the peer-reviewed literature and on the registry website.

This protocol was preregistered with the Australian New Zealand Clinical Trials Registry (registration approved on 4 August 2021; trial ID number: ACTRN12621001014842p).