Here is the design of a clinical trial:

Official Title: Age of Blood in Children in Pediatric Intensive Care Units

Included conditions:
- Anemia

Study Armgroups:
- {'label': 'Short storage', 'type': 'ACTIVE_COMPARATOR', 'description': 'Red blood cells storage duration of equal to or less than 7 days.', 'interventionNames': ['Biological: Short storage RBC age']}
- {'label': 'Standard issue', 'type': 'ACTIVE_COMPARATOR', 'description': 'Red blood cells storage duration of 2 to 42 days with an expected average length of storage of about 17-21 days.', 'interventionNames': ['Biological: Short storage RBC age']}

Interventions:
- {'type': 'BIOLOGICAL', 'name': 'Short storage RBC age', 'description': 'IND obtained to cover the expiration date on the red blood cell unit', 'armGroupLabels': ['Short storage', 'Standard issue']}

Primary Outcomes:
- {'measure': 'Number of Participants With New or Progressive Multiple Organ Dysfunction Syndrome (NPMODS)', 'description': 'The primary outcome measure of this RCT is NPMODS defined as the proportion of patients who die during the 28 days after randomization or who develop NPMODS. For patients with no organ dysfunction at randomization, New MODS is the development of ≥ 2 concurrent organ dysfunctions during the 28 days after randomization. For patients with 1 organ dysfunction at randomization, New MODS is the development of at least 1 other concurrent organ dysfunction after randomization. Patients with MODS (ie concurrent dysfunction of ≥ 2 organ systems) at randomization can develop Progressive MODS defined as development of at least 1 additional concurrent organ dysfunction at during the 28 days after randomization. All deaths will be considered Progressive MODS. NPMODS will be monitored up to 28 days or ICU discharge because it is almost never observed beyond this time in children.', 'timeFrame': '28 days after randomization'}

Please estimate the sample size based on the assumption: 
Sample size calculations are based on a two-tailed α of 0.05, a power (1 − β) of 0.90, and an expected dropout rate of 1.7%.
Sample size
        Patient eligibility criteria and short-storage definition (7-day cutoff) in ABC PICU will be similar to those used in preliminary studies (TableÂ 4) [1, 23]. Based on this prior work and on a large survey of North American intensivists [38], the incidence of NPMODS is expected to be 18% in the control group and 12% in the short-storage group and the relative risk is expected to be 33%. Sample size calculations based on these estimates for two independent proportions (chi-square) using a two-tailed Î± of 0.05 and a (1 â Î²) of 0.90 yield an estimate of 769 patients per arm (total: 1538) [42]. The ABC PICU Trial Steering Committee, the CCCTG (www.ccctg.ca), and the PALISI Network (www.palisi.org) support these estimates and the choice of a 33% relative risk difference because it is considered clinically important and sufficiently significant to change practice. The proportion of patients lost to follow-up is expected at 1.7% based on results of the TRIPICU study. The sample size for the ABC PICU trial is, therefore, 769 patients per arm (total: 1538) [42].Table 4Estimates for the absolute risk reduction expected in the ABC PICU trialAnalytic cohort study: Gauvin et al. [1]Descriptive cohort study: Karam et al. [2]Storage time cutoff for âfreshâ RBC unit7Â days7Â daysPICU expected length of stay>â24Â h>â48Â hHemodynamically unstable patientsNoYesNPMODS in transfused patients15%39.2%Odds ratio for development of NPMODS in older versus fresher (confidence interval)1.39 (0.42â4.61)1.54 (0.80â2.96)Estimated risk in experimental group 1/ORâ=â(p1/(1 â p1))/(p0/(1 â p0))11%22%MODS multiple organ dysfunction syndrome, NPMODS new or progressive multiple organ dysfunction syndrome, OR odds ratio, PICU pediatric intensive care unit, RBC red blood cell, RCT randomized controlled trial