Here is the design of a clinical trial:

Official Title: Intravenous Iron to Treat Postoperative Anemia in Older Cardiac Surgery Patients: a Randomized Controlled Trial'

Included conditions:
- Iron Deficiency Anemia

Study Armgroups:
- {'label': 'Intravenous iron (ferric derisomaltose)', 'type': 'EXPERIMENTAL', 'description': 'The intervention consists of a single dose of ferric derisomaltose (Monofer®) 100 mg/mL solution for infusion (Monofer® is a registered product with a marketing authorization in the Netherlands (RVG number: 103070). Manufacturer: Pharmacosmos A/S, Denmark. Dutch marketing authorization holder: Cablon Medical B.V). The method of administration and dosage of the investigational medication are standard treatment. The ferric derisomaltose dose will calculated for each patient depending on body weight (20mg/kg) and diluted in 250 ml NaCl 0.9%. Treatment takes approximately 60 minutes. Vital signs of the patient will be monitored during administration of the investigational medication and for 30 minutes afterwards', 'interventionNames': ['Drug: Ferric Derisomaltose 100 MG/ML']}
- {'label': 'Placebo', 'type': 'PLACEBO_COMPARATOR', 'description': 'Single dose of sodium chloride 0.9% (250ml). Treatment takes approximately 60 minutes. Vital signs of the patient will be monitored during administration of the investigational medication and for 30 minutes afterwards', 'interventionNames': ['Drug: Sodium chloride']}

Interventions:
- {'type': 'DRUG', 'name': 'Ferric Derisomaltose 100 MG/ML', 'description': 'Postoperative treatment with a single dose IVI (ferric derisomaltose), with a dose of 20mg/kg in approximately 60 minutes.', 'armGroupLabels': ['Intravenous iron (ferric derisomaltose)'], 'otherNames': ['Monofer']}
- {'type': 'DRUG', 'name': 'Sodium chloride', 'description': 'Postoperative treatment with a single dose NaCl 0.9% in approximately 60 minutes.', 'armGroupLabels': ['Placebo'], 'otherNames': ['Placebo']}

Primary Outcomes:
- {'measure': 'Disability', 'description': 'Disability measured by the 12- item World Health Organization Disability Assessment score 2.0 (WHODAS-12). Based on the answers a disability score can be calculated. 0% is no disability and 100% is fully disabled.', 'timeFrame': '90 days after elective cardiac surgery'}

Please estimate the sample size based on the assumption: 
Two-tailed unpaired T-test with a two-sided significance level of 5%, power of 80%, and a loss to follow-up margin of 10%.
Sample size {14}
        In the previously conducted AGE cohort (ClinicalTrials.gov Identifier NCT02535728) studying a similar patient population, the mean WHODAS 2.0 score for CABG and AVR patients after 3Â months was 12% points with a standard deviation (SD) of 15% points. For an expected effect size, a mean difference in WHODAS 2.0 score of 5% points or more between the treatment and placebo groups was chosen. This difference in WHODAS 2.0 score is consistent with a clinically relevant change in disability [18]. We based our sample size estimate on the most conservative (largest) standard deviation, which was 15% points. To detect a mean difference in WHODAS 2.0 score of 5% points at 90Â days using a two-tailed unpaired T-test with a two-sided significance level of 5% and a power of 80% with equal allocation to two arms would require 142 patients per treatment group. Taking into account a loss to follow-up margin of 10%, we aim to include a total cohort of 310 patients. Calculations were performed using R version 3.6.1âÂ© 2019â07-05, R, Inc., for Windows.