The Vibe Up Precision - Pilot Trial: Using Smartphone and Smartwatch Data to Predict Response to Smartphone-Based Interventions Among Australian University Students With Symptoms of Psychological Distress

GENERAL DESIGN This is a 4-arm pilot randomised controlled trial of 8 weeks duration designed to assess whether digital phenotyping markers predict response to brief smartphone-delivered interventions for psychological distress among university students in Australia. Each participant will undergo an initial 2-week pre-intervention period involving daily Ecological Momentary Assessment (EMA; Weeks 1 and 2), then will be randomly assigned to one of four trial arms (mindfulness, physical activity, sleep hygiene, control) that involve receiving access to their assigned intervention (or control) that they will complete for 2 weeks (Weeks 3 and Week 4), followed by continued access to their assigned intervention (or control) over a 4-week follow-up period (Weeks 5 to 8). PRE-INTERVENTION EMA PERIOD During the 2-week pre-intervention EMA period, participants will complete EMA twice per day. The EMA will run on a signal-contingent protocol consisting of two daily random prompts to the participant generated by a custom-built smartphone application at a random time within two windows: morning (08:00-10:00) and evening (19:00-21:00). Participants will have up to 60 minutes to respond to the prompt, with a reminder sent after 30 minutes if the prompt has not been responded to. Each EMA measurement will consist of an initial question asking if the participant is experiencing any of the emotions drawn from an extended Short Form (12 item) version of the internationally reliable form of the Positive and Negative Affect Schedule (I-PANAS). If any emotions are selected on this first question, the participant will be asked two follow-up questions exploring behavioural intentions as a result of measured feelings, intended to assess coping styles. INTERVENTION PERIOD At the end of Week 2, participants will be randomised to receive one of three interventions or a control for 2 weeks. These interventions consist of three active interventions (mindfulness, sleep hygiene, physical activity) and an EMA control intervention. All interventions are brief, app-delivered, self-guided digital informational/behavioural interventions. Each intervention is entirely separate but consists of a combination of brief modular information covering key concepts, delivered via infographics, as well as structured activities (e.g., practicing mindfulness using a guided audio). All four interventions have been used recently in the Vibe Up AI-enhanced adaptive trial (trial ID ACTRN12621001223820). A summary of the intervention content is as follows: ARM 1: MINDFULNESS The Mindfulness intervention starts with an introductory video (3 minutes), followed by five guided mindfulness practices delivered as audio recordings (3-5 minutes in length). The content of the modules is as follows: a) Introductory video: Explains what mindfulness is and the benefits; defines formal vs. informal mindfulness practice; how to tune into the five senses and bring mindful awareness to daily activities; and how to reduce judgment and increase self-compassion. b) Module 1: Guided mindfulness practice based on mindful awareness of breathing (audio with male/female voice options) c) Module 2: Guided mindfulness practice teaching non-judgment towards thoughts, using 'leaves on a stream' imagery (audio with male/female voice options) d) Module 3: Guided mindfulness practice based on mindful awareness of body sensations and releasing of muscle tension (audio with male/female voice options) e) Module 4: Guided mindfulness practice encouraging the use of all five senses to bring curiosity to everyday activities (audio with male/female voice options) f) Module 5: Guided mindfulness practice blending awareness of surrounding environment and bodily sensations (audio with male/female voice options) The modules are made available to participants as follows: • The introductory video is available to participants immediately after allocation to the intervention. • The first mindfulness audio guide becomes available immediately after the introductory video has been completed. • The subsequent mindfulness audio guides are sequentially released, at one day intervals (regardless of participant engagement). Expected effort: A minimum of one mindfulness audio completed daily at participants' convenience. All modules completed at least once by the end of the intervention period. Participants are also encouraged to practice bringing mindful awareness to activities throughout their day (‘informal’ mindfulness). ARM 2: PHYSICAL ACTIVITY The Physical Activity intervention starts with an introductory infographic explaining the benefits of physical activity for cognition, mental health and physical health, Australian guidelines for physical activity, how to set realistic goals and benefits of even small change, and tips to foster enjoyment of physical activity (e.g., being social, settings goals, tracking progress). It then prompts participants each day to choose a goal to increase their physical activity that day. An evidence-based seven-minute high-intensity circuit training (HICT) protocol is provided as one option for increasing physical activity. Other examples of exercises that are suggested within the intervention are walking, social sport, gardening, yoga, bike riding or dancing. The modules are made available to participants as follows: • An introductory infographic is available to participants immediately after allocation to the intervention. • The Daily goal setting and 7-minute workout becomes available immediately after a participant has completed the introductory infographic. Expected effort: Physical activity completed daily at participants' convenience, including a 7-minute work out three times weekly or, alternatively, increasing steps by 10% weekly. ARM 3: SLEEP HYGIENE The Sleep Hygiene intervention centres around four brief, sequential modules covering key sleep hygiene concepts, which are delivered via infographics. Each module takes up to five minutes to read. The content of the modules is as follows: a) Module 1: Why we sleep? Covers the recommended hours of sleep per night, the impact of lack of sleep on cognition and emotion, benefits of sleep for mental health and physical health, and an introduction to sleep hygiene. b) Module 2: Sleep habits. covers establishment of regular bedtime and wake time, eliminating or limiting naps, establishing a wind down routine. c) Module 3: Sleep environment. Covers how to reduce light, noise and temperature disturbance, and ensuring bedding is comfortable; limiting the use of bed to sleep and sex; the impact of electronic devices on sleep; get out of bed when unable to sleep for 20 minutes or more. d) Module 4: Reducing caffeine, alcohol and nicotine intake close to bedtime; eating a healthy diet; increasing physical activity and avoiding exercise close to bedtime. The modules are made available to participants as follows: • Module 1 is available to participants immediately after allocation to the intervention. • Module 2 becomes available immediately after a participant has completed Module 1. • Module 3 becomes available two days after Module 2 is made available (regardless of participant engagement). • Module 4 becomes available two days after Module 3 is made available (regardless of participant engagement). Expected effort: All modules completed at least once by the end of the intervention period. Participants are instructed to choose one strategy from each of Module 2 – 4 and implement it daily (total of 3 strategies by end of intervention period). ASSESSMENT OF ADHERENCE Throughout the intervention period, participants are asked to log their engagement with the intervention daily via an in-app logging question. For those assigned to the physical activity intervention, they are asked to log how many minutes of physical activity they engaged in that day; for those assigned to the sleep hygiene intervention, they are asked to log how many hours of sleep they got that day; and for those assigned to the mindfulness intervention, they are asked to rate how many minutes of mindfulness practice they engaged in that day. FOLLOW-UP PERIOD All participants will continue to have access to their assigned intervention throughout a 4-week follow-up period (Weeks 5 to 8). They will be encouraged to practice implementing the skills learned in the intervention.