Here is the design of a clinical trial:

Official Title: MusiC to Prevent deliriUm During neuroSurgerY: A Single Centered Prospective Randomized Controlled Trial

Included conditions:
- Delirium

Study Armgroups:
- {'label': 'Music', 'type': 'EXPERIMENTAL', 'description': 'Participants in the music group will receive headphones with music 30 minutes before surgery. Patients will be able to choose music from a preselected list composed by a team consisting of researchers and dedicated music therapists. The headphones will be removed before entering the operating room. Once in the operating room they will receive earphones after intubation, compatible with the Mayfield and site of operation. The intraoperative music intervention will be continued during the surgical procedure and discontinued just before detubation. The duration of the intraoperative music intervention depends on the duration of surgery and will be documented. After surgery, during recovery at the post-operative care unit (PACU) another 30 minutes of music through headphones will be given. The following 3 days (post-operative day 1, 2 and 3) at the neurosurgical ward they will receive music twice a day for 30 minutes. All participants will further receive standard of clinical care.', 'interventionNames': ['Other: Music']}
- {'label': 'Standard of clinical care', 'type': 'NO_INTERVENTION', 'description': 'Standard of clinical care.'}

Interventions:
- {'type': 'OTHER', 'name': 'Music', 'description': 'Participants in the music group will receive headphones with music 30 minutes before surgery. Patients will be able to choose music from a preselected list composed by a team consisting of researchers and dedicated music therapists. The headphones will be removed just before entering the operating room. Once in the operating room they will receive earphones after intubation, compatible with the Mayfield and site of operation. The intraoperative music intervention will be continued during the surgical procedure and discontinued just before detubation. The duration of the intraoperative music intervention depends on the duration of surgery and will be documented. After surgery, during recovery at the post-operative care unit (PACU) another 30 minutes of music through headphones will be given. The following 3 days at the neurosurgical ward they will receive music twice a day for 30 minutes.', 'armGroupLabels': ['Music']}

Primary Outcomes:
- {'measure': 'Delirium', 'description': 'All participating patients on the ward will be screened using the Delirium Observation Screening (DOS) scale. The DOS is a score of 1 until 13, in which a score of 3 or higher is suspicious for delirium. Screening is conducted 3 times per day (i.e. during each shift) and maintained until day 5. In case of raised suspicion of delirium by DOS, a psychiatrist is consulted to confirm or reject clinical diagnosis of delirium based on the DSM-V criteria. Presence of delirium is confirmed by the psychiatrist after positive DOS screening, all other patients will be considered as absence of delirium. In case of discharge towards another hospital within 5 days, onset of delirium is evaluated in that hospital. In case of discharge within 5 days towards home without delirium, it will be considered as no delirium.', 'timeFrame': 'First five post-operative days. In case of discharge within 5 days towards home without delirium, it will be considered as no delirium.'}

Please estimate the sample size based on the assumption: 
Assuming a power of 80%, a two-sided p value of 0.05, and 1:1 randomisation. We expect a lost to follow-up of 5%.
Sample size
        We expect an incidence of delirium in our control group of 30%. This is based on literature documenting incidence of delirium in neurosurgical patients in a northern European population of 29%â33%.4â6 8â13 62 The expected effect cannot be based on previous literature since no adequate trials exist on the effect of music on delirium. Other non-pharmacological interventions mention a relative reduction of 36%â77%.19 22 We will, therefore, consider the intervention clinically relevant if a relative reduction of 60%, corresponding to an absolute reduction of 18%, is achieved. Assuming a power of 80%, a two-sided p value of 0.05, and 1:1 randomisation, a sample size of 90 patients per arm would be required. We expect a lost to follow-up of 5% and will, therefore, include 189 patients.
        
          Inclusion period
          We expect 50% of the craniotomy patients not to be eligible due to inclusion or exclusion criteria given above. This leaves 240 eligible patients each year, taking into account that approximately 480 craniotomies are conducted at the Erasmus MC in Rotterdam each year. In 30% of these cases, it concerns emergency operations and we do not expect to be able to include many of these patients. Considering this, we would in theory therefore need 14 months for inclusion. Hence, we would plan 24 months of inclusion time taking into account all the logistic challenges. In practice, this comes down to one or two inclusions each week.