Here is the design of a clinical trial:

Official Title: Multi-centre Randomised Trial to Evaluate the Effect of Early Hypothermia on Neurological Function in Patients With Severe Traumatic Brain Injury. Including Renal Sub Study

Included conditions:
- Brain Injuries, Traumatic

Study Armgroups:
- {'label': 'Hypothermia', 'type': 'EXPERIMENTAL', 'description': 'Early and sustained hypothermia.', 'interventionNames': ['Other: Hypothermia']}
- {'label': 'Normothermia', 'type': 'NO_INTERVENTION', 'description': 'Standard management'}

Interventions:
- {'type': 'OTHER', 'name': 'Hypothermia', 'description': 'exposure: Early and sustained hypothermia. Hypothermia will initially be induced by infusion of up to 2L ice cold saline. Following a safety assessment the patient will be rapidly cooled to 33C using surface temperature control equipment. They will be maintained at 33C for 72 hours. Rewarming will occur at a rate of 1C/4hrs and will be titrated to intracranial pressure (ICP) control and BP.', 'armGroupLabels': ['Hypothermia']}

Primary Outcomes:
- {'measure': 'The proportion of favourable neurological outcomes (Glasgow Outcome Score Extended: GOSE 5 to 8)', 'description': 'The Glasgow Outcome Scale Extended (GOSE) is an ordinal rating scale. The 8 scores in the scale are: Dead (1), Vegetative State (2), Lower Severe Disability (3), Upper Severe Disability (4), Lower Moderate Disability (5), Upper Moderate Disability (6), Lower Good Recovery (7), and Upper Good Recovery (8).', 'timeFrame': '6 months post injury'}

Please estimate the sample size based on the assumption: 
The study assumes a two-sided alpha of 0.05, power of slightly >80% (82.8%), and uses an uncorrected Chi square test. It also accounts for a 5% loss to follow-up, a maximum of 12% non-compliance, and interim analyses using Haybittle-Peto 3SD group sequential boundaries. The final analysis significance level is adjusted to ±1.996 SD (P=0.0459) instead of ±1.96 SD (P=0.05).
Sample size, power and interim analysis schedule
        The overall recruitment target was set at 500 participants from commencement in December 2010 and was slightly increased to 510 participants in September 2017 after blinded review of the combined proportion of patients with âconsent withdrawnâ or âloss to follow-upâ. A total of 511 patients were randomised before the conclusion of trial recruitment on 10 November 2017.
        A study of fixed size with full compliance and follow-up would require 364 patients (182 in each of two treatment arms) to detect a 15% absolute increase from 50% to 65% in favourable neurological outcome at sixÂ months following injury (equivalent to a 30% relative improvement in risk) with slightly >â80% (82.8%) power, assuming a two-sided alpha of 0.05 and an uncorrected Chi square test. This postulated POLAR risk improvement from a baseline of 50% to 65% in treated patients is equivalent to an odds ratio of approximately 1.86.
        The original POLAR trial sample size of 364 fully evaluable patients was appropriately inflated to a practically required target of 500 patients to maintain 80% power to find the anticipated beneficial effect of prophylactic hypothermia while accommodating anticipated losses to follow-up (5%) and non-compliance (cross-over from cooling to control and related losses, maximum 12%). Also incorporated was a much smaller (0.7%) inflation necessary to accommodate the originally anticipated interim analyses of both mortality and the proportion of unfavourable neurological outcomes using Haybittle-Peto 3SD group sequential boundaries at two recruitment points (one-quarter [nâ=â125] and one-half [nâ=â250]) [7].
        Following the October 2015 publication of the EUROTHERM3235 study [6], the POLAR DSMC required a further substantial increase in interim monitoring, namely at increments of 50 patients from nâ=â300 to nâ=â450 inclusive. Ten of 11 planned interim analyses will be of both mortality and the proportion of unfavourable neurological outcomes, while at the penultimate (nâ=â450) assessment, short-term 28-day mortality alone will be assessed due to time constraints. These extra analyses implied a sample size inflationary requirement (4% - 0.7%â=â3.3% extra) [44] which may be accommodated within the originally planned sample size, provided losses to follow-up and non-compliance remained below anticipated limits.
        From calculations using East trial design software [45] based upon an approximate Chi-square test, the trial power was only slightly diminished at 82.3% (down from 83%) with 366 fully evaluable participants and 11 interim Haybittle-Peto 3SD interim analyses. In the absence of early stopping, the final analysis would be properly conducted at Â±â1.996 SD (PÂ =â0.0459) rather than Â±â1.96 SD (PÂ =â0.05). This level of significance will not be adjusted for multiplicity; however, the primary trial outcome is clearly defined and the conclusions of the study will be those based on the primary analysis conducted in the ITT full analysis patient set. Unless otherwise specified, all hypothesis tests and accompanying significance levels (that is, P values) will be two-sided, with 95% CI.