Here is the design of a clinical trial:

Official Title: A Pragmatic Factorial Design Randomised Controlled Study to Assess the Efficacy of the Implementation of a Prehabilitation Programme in Patients Undergoing Elective Major Intra - Cavity Cancer Surgery in Wessex

Included conditions:
- Cancer

Study Armgroups:
- {'label': 'Control', 'type': 'NO_INTERVENTION', 'description': 'Usual care plus additional monitoring'}
- {'label': 'SRETP', 'type': 'EXPERIMENTAL', 'description': 'Structured Responsive Exercise Training Programme (SRETP) prior to surgery', 'interventionNames': ['Behavioral: SRETP']}
- {'label': 'Psychological support', 'type': 'EXPERIMENTAL', 'description': 'Psychological support prior to surgery', 'interventionNames': ['Behavioral: Psychological support']}
- {'label': 'SRETP and psychological support', 'type': 'EXPERIMENTAL', 'description': 'Structured Responsive Exercise Training Programme (SRETP) and psychological support prior to surgery', 'interventionNames': ['Behavioral: SRETP', 'Behavioral: Psychological support']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'SRETP', 'description': 'SRETP will involve short periods of exercise at a high intensity interspersed with short periods of exercise at a moderate intensity (aerobic interval training). We will also include resistance training in each session. Exercise intensities during the interval exercise-training program are specific to each patient and derived from CPET. Moderate intensity exercise is below the anaerobic threshold (AT). Patients will exercise at 80% of oxygen uptake (VO2) obtained at the anaerobic threshold (80%AT) for moderate intensity exercise - 3 minutes. Severe exercise intensity is recognised as 50% of the difference between the VO2 AT and VO2 Peak (50%∆) - 2 minutes.', 'armGroupLabels': ['SRETP', 'SRETP and psychological support']}
- {'type': 'BEHAVIORAL', 'name': 'Psychological support', 'description': 'Support sessions will be patient-centred, giving the patient an opportunity to raise any issues/concerns they are having, this may include (but will not be limited to) ways of coping with their reactions to cancer, family and relationship issues, exploring personal issues and dealing with practical issues. Patients will have access to other resources available at the cancer centres including but not restricted to further information about their condition and how to access financial support. These processes reflect the best practice currently being delivered by cancer support centre staff in the Wessex region. Any patient deemed at risk (i.e. from suicidal ideation or self harm) will be reported to their GP, followed up by a letter.', 'armGroupLabels': ['Psychological support', 'SRETP and psychological support']}

Primary Outcomes:
- {'measure': 'Post-operative length of hospital stay', 'description': 'Date of hospital admission minus date of discharge would equal length of post-operative stay (LOS).', 'timeFrame': 'up to 1 year'}

Please estimate the sample size based on the assumption: 
85% power, alpha = 0.05, and a 20% drop-out rate.
Estimation of sample size
      From previous studies, the median length of stay in the control group is estimated to be 7 days. To detect a clinically meaningful difference of a (significance level to detect a hazard ratio of 1.17 when the control group median in-patient time is 7 days) 1 day reduction in LOS with 85% power, alpha = 0.05, a sample size of 1560 participants will need to be recruited over 3 years, with a one year follow-up period. The sample size allows for a 20% drop-out.
      Sample size calculations for 2Ã2 designs are based on the two main comparisons (i.e. exercise vs. no exercise and psychological support vs. no support). The trial sample size is the larger of these 2 comparisons, so in this case, the sample size calculation is powered on the psychological support comparison. The sample size calculation assumes that there is no interaction between the interventions.