02885nas a2200349   4500000000100000008004100001260001700042100001800059700001900077700002200096700001900118700002200137700001400159700002000173700002100193700001800214700002500232700001900257700002200276700001300298700001500311700001400326700002400340700002100364700001400385700001600399245013400415300001200549490000700561520195300568022001402521       2017                            d  c1825845553111 aWoodward Mark1 aAnderson Craig1 aRobinson Thompson1 aArima Hisatomi1 aHeritier Stephane1 aHackett M1 aMiddleton Sandy1 aVenturelli Paula1 aLavados Pablo1 aOlavarría Verónica1 aBillot Laurent1 aBrunser Alejandro1 aPeng Bin1 aCui Liying1 aSong Lily1 aPontes-Neto Octavio1 aWatkins Caroline1 aLim Joyce1 aJan Stephen00aStatistical analysis plan for the Head Position in Stroke Trial (HeadPoST): An international cluster cross-over randomized trial.  a667-6700 v123 a<p>
Background There is evidence to indicate that the lying flat head position increases cerebral blood flow and oxygenation in patients with acute ischemic stroke, but how these physiological effects translate into clinical outcomes is uncertain. The Head Position in Stroke Trial aims to determine the comparative effectiveness of lying flat (0°) compared to sitting up (≥30°) head positioning, initiated within 24 h of hospital admission for patients with acute stroke. Design An international, pragmatic, cluster-randomized, crossover, open, blinded outcome assessed clinical trial. Each hospital with an established acute stroke unit (cluster) site was required to recruit up to 140 consecutive cases of acute stroke (one phase of head positioning before immediately crossing over to the other phase of head positioning), including both acute ischemic stroke and intracerebral hemorrhage, in each randomized head position as a 'business as usual' policy. Objective To outline in detail the predetermined statistical analysis plan for the study. Methods All accumulated data will be reviewed and formally assessed. Information regarding baseline characteristics of patients, their process of care and management will be outlined, and for each item, statistically relevant descriptive elements will be described. For the trial outcomes, the most appropriate statistical comparisons are described. Results A statistical analysis plan was developed that is transparent, verifiable, and predetermined before completion of data collection. Conclusions We developed a predetermined statistical analysis plan for Head Position in Stroke Trial to avoid analysis bias arising from prior knowledge of the findings, in order to reliably quantify the benefits and harms of lying flat versus sitting up early after the onset of acute stroke. Trial registration ClinicalTrials.gov identifier NCT02162017; ANZCTR identifier ACTRN12614000483651.
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