Here is the design of a clinical trial:

Official Title: Potential Benefit in Information Providing and Influence on Patient Anxiety and Satisfaction by Means of Preoperative Explanatory Videos in Total Extraperitoneal Inguinal Hernioplasty: a Multicenter Randomized Controlled Trial

Included conditions:
- Inguinal Hernia

Study Armgroups:
- {'label': 'Hernia video', 'type': 'ACTIVE_COMPARATOR', 'description': 'The video of the intervention group will provide a short (\\< 5 min) summary explaining the basic principles of endoscopic extraperitoneal hernia repair, its possible complications and the postoperative course. After carefully watching the video, participants should be able to correctly answer to a multiple-choice test consisting of 12 questions related to the aforementioned topics.', 'interventionNames': ['Other: Explanatory video']}
- {'label': 'Mock video', 'type': 'PLACEBO_COMPARATOR', 'description': 'This video is a general documentation of the "typical" day of surgery in the day clinic. The information is essentially limited to the pictorial representation of the individual wards which the patient will pass through during the operation (arrival at the clinic, admission, transport to the operating theatre, recovery room, discharge).\n\nThe video explicitly does not transport any information that could be helpful for answering the quiz questions or for medical understanding of the operation itself.', 'interventionNames': ['Other: Explanatory video']}
- {'label': 'Control group', 'type': 'SHAM_COMPARATOR', 'description': 'The link of the third group leads to a digital version of the information sheet, which has already been discussed with all patients during the informed consent discussion. The digital version of the informed consent form allows the patient to read the information again. The third group thus corresponds to the standard of care.', 'interventionNames': ['Other: Informed consent form']}

Interventions:
- {'type': 'OTHER', 'name': 'Explanatory video', 'description': 'Links to explanatory videos handed out to patients to be watched at home after standard informed consent giving', 'armGroupLabels': ['Hernia video', 'Mock video']}
- {'type': 'OTHER', 'name': 'Informed consent form', 'description': 'Links to a digital version of the informed consent form already discussed during the process of informed consent giving.', 'armGroupLabels': ['Control group']}

Primary Outcomes:
- {'measure': 'Score in multiple-choice-test', 'description': 'Quiz with questions regarding background, indication, implementation, complications and postoperative course of the total extraperitoneal inguinal h ernioplasty (TEP) procedure. The questions asked check relevant aspects for the patient with regard to the planned operation. The structure of the multiple-choice quiz takes the "single best option" out of 12 questions. Maximum value of the test is 12 (12/12, highest score-best outcome), the lowest 0 (0/12, lowest score-worst outcome).\n\nThe questions are clearly posed and the correct answer is based on current guidelines for the management of inguinal hernia, which have been published by the European Hernia Society (EHS), American Hernia Society (AHS), International Endo Hernia Society (IEHS) and the European Association for Endoscopic Surgery and Other Interventional Techniques (EAES) as a consensus document by "HerniaSurge".', 'timeFrame': 'assessed 1-2 days after group allocation/exposure'}

Please estimate the sample size based on the assumption: 
significance level (α)=0.05, power=0.8, dropout rate=15%
Sample size calculation
          Based on a previous study,17 we calculated, a priori for the investigation of the primary outcome, a total number of 183 patients. This number was calculated for the primary outcome. According to this case number estimation 61 patients per group should be included. Using g-power,18 an analysis of variance analysis was performed and a drop-out rate of 15% was postulated (power=0.8; âº=0.05; f=0.25; N(min)=159).