title: Statistical analysis plan of the head position in acute ischemic stroke trial pilot (HEADPOST pilot).
abstract: Background The HEADPOST Pilot is a proof-of-concept, open, prospective, multicenter, international, cluster randomized, phase IIb controlled trial, with masked outcome assessment. The trial will test if lying flat head position initiated in patients within 12 h of onset of acute ischemic stroke involving the anterior circulation increases cerebral blood flow in the middle cerebral arteries, as measured by transcranial Doppler. The study will also assess the safety and feasibility of patients lying flat for ≥24 h. The trial was conducted in centers in three countries, with ability to perform early transcranial Doppler. A feature of this trial was that patients were randomized to a certain position according to the month of admission to hospital. Objective To outline in detail the predetermined statistical analysis plan for HEADPOST Pilot study. Methods All data collected by participating researchers will be reviewed and formally assessed. Information pertaining to the baseline characteristics of patients, their process of care, and the delivery of treatments will be classified, and for each item, appropriate descriptive statistical analyses are planned with comparisons made between randomized groups. For the outcomes, statistical comparisons to be made between groups are planned and described. Results This statistical analysis plan was developed for the analysis of the results of the HEADPOST Pilot study to be transparent, available, verifiable, and predetermined before data lock. Conclusions We have developed a statistical analysis plan for the HEADPOST Pilot study which is to be followed to avoid analysis bias arising from prior knowledge of the study findings. Trial registration The study is registered under HEADPOST-Pilot, ClinicalTrials.gov Identifier NCT01706094.
authors.affiliation: 1 Unidad de Neurología Vascular, Servicio de Neurología, Departamento de Medicina Interna, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago, Chile.
authors.forename: Verónica V
authors.initials: VV
authors.lastname: Olavarría
authors.affiliation: 2 Department of Preventive Medicine and Public Health, Faculty of Medicine, Fukuoka University, Fukuoka, Japan.|3 The George Institute for Global Health, Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Hisatomi
authors.initials: H
authors.lastname: Arima
authors.affiliation: 3 The George Institute for Global Health, Sydney Medical School, University of Sydney, Sydney, NSW, Australia.|4 Neurology Department, Royal Prince Alfred Hospital, Sydney, NSW, Australia.
authors.forename: Craig S
authors.initials: CS
authors.lastname: Anderson
authors.affiliation: 1 Unidad de Neurología Vascular, Servicio de Neurología, Departamento de Medicina Interna, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago, Chile.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Brunser
authors.affiliation: 1 Unidad de Neurología Vascular, Servicio de Neurología, Departamento de Medicina Interna, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago, Chile.|3 The George Institute for Global Health, Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Paula
authors.initials: P
authors.lastname: Muñoz-Venturelli
authors.affiliation: 3 The George Institute for Global Health, Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Laurent
authors.initials: L
authors.lastname: Billot
authors.affiliation: 1 Unidad de Neurología Vascular, Servicio de Neurología, Departamento de Medicina Interna, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago, Chile.|5 Departamento de Ciencias Neurológicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Pablo M
authors.initials: PM
authors.lastname: Lavados
mesh_terms: D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D002560:Cerebrovascular Circulation; D003627:Data Interpretation, Statistical; D005240:Feasibility Studies; D005500:Follow-Up Studies; D006257:Head / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D038622:Internationality; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D056888:Patient Positioning; D010865:Pilot Projects; D011187:Posture / Q000502:physiology; D012039:Regional Blood Flow; D020521:Stroke / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial
keywords: Cerebral blood flow velocity; head position; ischemic stroke; middle cerebral artery; pilot trial; statistical analysis plan; transcranial Doppler