Here is the design of a clinical trial:

Official Title: Making Shoulder Pain Simple in General Practice-implementing an Evidenced Based Guideline for Shoulder Pain, a Hybrid Design Cluster Randomised Study

Included conditions:
- Shoulder Pain
- Frozen Shoulder
- Rotator Cuff Tendinosis
- Myalgia
- Rotator Cuff Impingement Syndrome
- Rotator Cuff Tear or Rupture, Not Specified as Traumatic

Study Armgroups:
- {'label': 'Intervention', 'type': 'EXPERIMENTAL', 'description': 'Patients will be assessed by GPs who have attended an outreach workshop and trained at using an evidence based strategy for shoulder examination and treatment. GPs will have access to a decision support tool and patients is offered a tailored information package for self management.', 'interventionNames': ['Other: Evidence based treatment strategy', 'Other: Targeted patient information package']}
- {'label': 'Treatment as usual (TAU)', 'type': 'ACTIVE_COMPARATOR', 'description': 'The participants enrolled in the control period will receive treatment as offered in general practice.', 'interventionNames': ['Other: Treatment as usual (TAU)']}

Interventions:
- {'type': 'OTHER', 'name': 'Evidence based treatment strategy', 'description': 'Evidence-based clinical examination and treatment plan', 'armGroupLabels': ['Intervention']}
- {'type': 'OTHER', 'name': 'Targeted patient information package', 'description': 'GPs will in cooperation with the patients tailor a information package targeted to the patients needs regarding their clinical shoulder diagnosis and individual implications and needs (Pain, sleep, exercises etc.).', 'armGroupLabels': ['Intervention']}
- {'type': 'OTHER', 'name': 'Treatment as usual (TAU)', 'description': 'Usual care as provided by the GP', 'armGroupLabels': ['Treatment as usual (TAU)']}

Primary Outcomes:
- {'measure': 'Change in Shoulder Pain and Disability Index (SPADI)', 'description': '13 item patient reported questionnaire on shoulder pain and disability. (0 = no pain or shoulder disability, 100 = worst pain and disability).', 'timeFrame': 'Change from 0 to 12 weeks'}

Please estimate the sample size based on the assumption: 
Statistical power of 80%, alpha at 0.05 for a two-sided test, ICC of 0.02, and a possible drop-out rate of 10%.
Sample size
        The target sample size is 250âpatients. The incidence of shoulder pain in general practice has been reported to be 2%â4%.1 2 Based on the ICPC-2 codes for shoulder pain, we found that 67âpatients were given a primary shoulder diagnosis in a GP surgery with three GPs in Ãstfold County in Norway in 2017. Most GP surgeries have three to four GPs in Norway. Therefore, in estimating the sample size for this study, we used a conservative assumption of 3% as the incidence of shoulder pain. Previous studies guided our choice of estimates for the sample size calculation. We used the computer programme IBM SPSS Sample Power V.3.01 and inflated by the design effect using the formula DE=1+n-1Ï where n is the number of individuals per clusters and Ï the intracluster correlation coefficient (ICC).30â33 Setting the desired statistical power of the study at 80%, alpha at 0.05 for a two sided test and an ICC of 0.02, we estimated that we needed to recruit 250âpatients to detect a clinically important difference of 8 points between the groups in the SPADI score and an SD of 22 points in both groups, taking into account a possible drop-out rate of 10%. Thus, assuming that only one-third of the patients contacting their GP will participate in the study, we will recruit at least 36 GPs in 10 GP-clusters to recruit an adequate sample size in 1âyear. We will if necessary, increase the recruitment period to reach an adequate targeted sample size.