Here is the design of a clinical trial:

Official Title: Efficacy of Mindfulness-based Therapy vs. Relaxation in Prevention of Burnout in Medical Students : A Multicenter, Single Blind Randomized Controlled Study

Included conditions:
- Burnout
- Emotional Disturbances
- Depression

Study Armgroups:
- {'label': 'Mindfulness Based Stress Reduction (MBSR)', 'type': 'EXPERIMENTAL', 'description': '306 participants will be randomized in the MBSR program, consisting of 8 weekly sessions lasting 2 and half hours each. In addition to this, they will be asked to complete 30 minutes of home practice each day. In order to avoid forgetting techniques and to reinforce motivation, a MBSR recall session will be offered six month after intervention.\n\nAll the sessions may be carried out remotely, by videoconference. In this case, both programs should be conducted in this way in order to ensure comparability..', 'interventionNames': ['Other: Mindfulness Based Stress Reduction']}
- {'label': 'Progressive Muscle Relaxation Training (PMRT)', 'type': 'ACTIVE_COMPARATOR', 'description': '306 participants will be randomized in a relaxation program, consisting of 8 weekly sessions lasting 2 and half hours each. In addition to this, they will be asked to complete 30 minutes of home practice each day. In order to avoid forgetting techniques and to reinforce motivation, a relaxation recall session will be offered six month after intervention.\n\nAll the sessions may be carried out remotely, by videoconference. In this case, both programs should be conducted in this way in order to ensure comparability', 'interventionNames': ['Other: Relaxation group']}

Interventions:
- {'type': 'OTHER', 'name': 'Mindfulness Based Stress Reduction', 'description': "MBSR teaches mindfulness meditation and mindful yoga exercises to develop non-judgmental awareness of moment-to-moment experience. The intervention duration is 8 weeks, with weekly two and half hours sessions. It will be delivered according to the fundamental concepts and specific techniques provided in the MBSR manualized protocol by Kabat-Zinn. The program also includes 30-min daily homework exercises.\n\nMBSR teaches four main mindfulness practices: (1) body scan, a process of moving attention through the body; (2) mindful movement, consisting of gentle yoga stretches to develop awareness of body in movement; (3) sitting meditation; and (4) walking meditation. Inquiry and didactic teaching is also a part of MBSR and allows for some detailed exploration of participants' experiences.", 'armGroupLabels': ['Mindfulness Based Stress Reduction (MBSR)']}
- {'type': 'OTHER', 'name': 'Relaxation group', 'description': 'control group', 'armGroupLabels': ['Progressive Muscle Relaxation Training (PMRT)']}

Primary Outcomes:
- {'measure': 'Emotional exhaustion assessed with the Maslach Burnout Inventory (MBI)', 'description': 'Evaluation of the emotional exhaustion based on the MBI score. The MBI contains three subscales, one of which assesses emotional exhaustion through 9 items. A score below 17 indicates a low degree of emotional exhaustion, a score between 18 and 29 indicates a moderate degree of emotional exhaustion and a score above 30 indicates a high degree of emotional exhaustion. Higher scores reflect greater experienced burnout.', 'timeFrame': 'at 12 months'}

Please estimate the sample size based on the assumption: 
The statistical power is 80% with a 2-sided α level of 0.05. The percentage of participants lost to follow-up is estimated at 10%.
Sample size
        The sample size calculation was based on the results of the work by Verweij et al. [24]. In this randomized controlled trial, the mean baseline score of the emotional exhaustion subscale of the Maslach Burnout Inventory (MBIn) [25]. of 148 residents working in one of the medical, surgical or primary care disciplines was 15.6 (SDâ=â7.5). Assuming that the baseline score distribution will remain unchanged at the end of the trial in the MBI group, 274 students per group are required to show a significant mean between-group difference of 1.8 points for the emotional exhaustion subscale score at the end of the trial (15.6 for the MBI group and 17.4 for the RI group) with a statistic power of 80% and a 2-sided Î± level of 0.05. The percentage of participants lost to follow-up is estimated at 10%. Therefore, in total 612 students need to be recruited in the nine universities participating in the trial.