Here is the design of a clinical trial:

Official Title: The Effectiveness of a Modern Educational Intervention for Pain-related Disability After Breast Cancer Surgery: Randomized Controlled Trial

Included conditions:
- Breast Neoplasm
- Pain

Study Armgroups:
- {'label': 'Intervention group', 'type': 'EXPERIMENTAL', 'description': 'Standard physical therapy program + Modern educational program', 'interventionNames': ['Other: Standard physical therapy program', 'Other: Modern educational program']}
- {'label': 'Control group', 'type': 'ACTIVE_COMPARATOR', 'description': 'Standard physical therapy program + Traditional biomedical educational program', 'interventionNames': ['Other: Standard physical therapy program', 'Other: Traditional biomedical educational program']}

Interventions:
- {'type': 'OTHER', 'name': 'Standard physical therapy program', 'description': 'Mobilisations, stretching, scar tissue treatment and exercises\n\n* Start immediately after surgery, sessions are individual and take 30 minutes\n* Intensive phase (4 months): 1-2x/week\n* Maintenance phase (8 months, 3 sessions): 6, 8 and 12 months post-surgery', 'armGroupLabels': ['Control group', 'Intervention group']}
- {'type': 'OTHER', 'name': 'Modern educational program', 'description': 'This modern neuroscience educational approach is suited to explain more complex issues associated with pain such as the involvement of peripheral and central mechanisms, neuroplasticity and pain behaviour.\n\n* Sessions are individual and take 30 minutes, in addition to the standard physical therapy sessions\n* 3 sessions during week 1-2, 3 booster sessions at 6, 8 and 12 months post-surgery', 'armGroupLabels': ['Intervention group']}
- {'type': 'OTHER', 'name': 'Traditional biomedical educational program', 'description': "Traditional educational interventions are applied according to the biomedical model. This means that the patient's pain experience is explained from a tissue (injured versus healthy tissue) and biomechanics perspective\n\n* Sessions are individual and take 30 minutes, in addition to the standard physical therapy sessions\n* 3 sessions during week 1-2, 3 booster sessions at 6, 8 and 12 months post-surgery", 'armGroupLabels': ['Control group']}

Primary Outcomes:
- {'measure': 'Self-reported Change in Pain-related Disability', 'description': "Measured with Pain Disability Index, an instrument for measuring the impact that pain has on the ability of a person to participate in essential life activities. Scores between 0 and 70. The higher the score the greater the person's disability due to pain.", 'timeFrame': 'Change between baseline and one year follow-up assessment'}

Please estimate the sample size based on the assumption: 
80% power, significance level (alpha) of 0.05, and a drop-out rate of approximately 5%.
Sample size
        A power calculation was performed by the Leuven Biostatistics and statistical bioinformatics Centre of KU Leuven (Katholieke Universiteit Leuven) for the primary outcome parameter âPDI after 1âyearâ. Sample size calculation was based on data available inÂ the literature for the PDI.39 40 and calculated to detect with 80% power a difference of 20% in PDI after 1âyear. Assuming a coefficient of variation (CV) equal to 0.5, 87 participants per group are needed based on a two-sample pooled t-test of a mean ratio with lognormal data and setting alpha equal to 0.05. The assumed CV is a conservative estimate, derived from the observed CV of 0.30 in a sample of normative data for women with chronic pain. To anticipate a drop-out rate of approximately 5%, 184 participants in total will be recruited. The drop-out rate is based on previous similar trials at our institution.24 25 29 To handle the potential missing measurements after 1âyear, the comparison of the PDI will be based on a multivariate normal model for longitudinal measurements fitted on all repeated measures over time (preoperative, postoperative, 4, 6, 8, 12 and 18 months). A log-transformation will be applied if necessary to handle the right-skewed distribution of the PDI.