Here is the design of a clinical trial:

Official Title: Role of Delay and Antibiotics on PERForation Rate While Waiting appendECTomy - Randomized Non-inferiority Trial

Included conditions:
- Appendicitis

Study Armgroups:
- {'label': 'Surgery within 8 hours, no antibiotics', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients are planned for urgent operation, that should be done within 8 hours. Operation can be done during the night time. Patients do not receive antibiotics while waiting surgery. Prophylactic antibiotics are given 0-30 minutes before incision.', 'interventionNames': ['Drug: No antibiotics', 'Other: urgent schedule']}
- {'label': 'Surgery within 24 hours, no antibiotics', 'type': 'EXPERIMENTAL', 'description': 'Patients are planned for urgent operation, that should be done within 24 hours. Operations are not done during the night time (00:00 - 08:00), unless necessary to avoid delay over 24 hours. Patients do not receive antibiotics while waiting surgery. Prophylactic antibiotics are given 0-30 minutes before incision.', 'interventionNames': ['Drug: No antibiotics', 'Other: less urgent schedule']}
- {'label': 'Surgery within 8 hours, antibiotics', 'type': 'EXPERIMENTAL', 'description': 'Patients are planned for urgent operation, that should be done within 8 hours. Antibiotics (cefuroxime 1.5g and metronidazole 500mg every 8 hours) are given while waiting surgery.', 'interventionNames': ['Drug: Antibiotics, cefuroxime and metronidazole', 'Other: urgent schedule']}
- {'label': 'Surgery within 24 hours, antibiotics', 'type': 'EXPERIMENTAL', 'description': 'Patients are planned for urgent operation, that should be done within 24 hours. Operations are not done during the night time (00:00 - 08:00), unless necessary to avoid delay over 24 hours. Antibiotics (cefuroxime 1.5g and metronidazole 500mg every 8 hours) are given while waiting surgery.', 'interventionNames': ['Drug: Antibiotics, cefuroxime and metronidazole', 'Other: less urgent schedule']}

Interventions:
- {'type': 'DRUG', 'name': 'Antibiotics, cefuroxime and metronidazole', 'description': 'Patient receives antibiotics while waiting appendectomy', 'armGroupLabels': ['Surgery within 24 hours, antibiotics', 'Surgery within 8 hours, antibiotics']}
- {'type': 'DRUG', 'name': 'No antibiotics', 'description': 'No antibiotics are given while waiting surgery.', 'armGroupLabels': ['Surgery within 24 hours, no antibiotics', 'Surgery within 8 hours, no antibiotics']}
- {'type': 'OTHER', 'name': 'urgent schedule', 'description': 'Patients can wait up to 8 hours for surgery.', 'armGroupLabels': ['Surgery within 8 hours, antibiotics', 'Surgery within 8 hours, no antibiotics']}
- {'type': 'OTHER', 'name': 'less urgent schedule', 'description': 'Patients can wait up to 24 hours for surgery.', 'armGroupLabels': ['Surgery within 24 hours, antibiotics', 'Surgery within 24 hours, no antibiotics']}

Primary Outcomes:
- {'measure': 'Complicated appendicitis', 'description': 'Surgical finding is complicated appendicitis (AAST Grade III-V)', 'timeFrame': 'during surgery'}

Please estimate the sample size based on the assumption: 
To declare non-inferiority, a power of 90 per cent with a significance level (alpha) of 0.05 is required. An assumed dropout rate of 2 to 3 per cent is considered.
Sample size calculation
        Twenty-two per cent of patients with uncomplicated appendicitis on CT were found to be perforated at operation in adults when median in-hospital waiting time for the surgery was over 8 hours5. In the same study, it was estimated that the risk of perforation increases by 2 per cent every hour. On the other hand, in patients with CRP less than 100 mg/l on admission, the rate of perforated appendicitis was 14 per cent8.
        The aim is to show that in patients with presumed uncomplicated appendicitis, scheduling appendicectomy within 24 hours does not lead to absolute increase in the rate of perforated appendicitis (AAST grade IIIâV) compared with scheduling the appendicectomy within 8 hours. It is assumed that in this patient population the rate of perforated appendicitis would be 15 per cent. The non-inferiority margin was set at 5 percentage points in difference of proportions of perforated appendicitis between the arms. To declare the non-inferiority, 1748 patients are needed to achieve a power of 90 per cent (Ï2) with 0.05 alpha. To take into account an assumed 2 to 3 per cent drop off rate, sample size is set to 1800 patients.
        In the antibiotic layer, an identical (5 percentage points) non-inferiority margin in difference of proportions of perforated appendicitis was set with identical sample size calculation.
        Patient recruiting started in May 2020 and the recruitment is estimated to take 2 years.