title: Risk of intracranial hemorrhage in users of oral antithrombotic drugs: Study protocol for a nationwide study.
abstract: Background A wide range of antithrombotic medications can be used in the prevention and treatment of thrombosis. Among hemorrhagic complications of antithrombotic drugs, intracranial hemorrhage may have particularly devastating consequences with high morbidity, disability and mortality rates. The incidence and risks of intracranial hemorrhage in patients on antithrombotic treatments from regular clinical practice outside clinical trials remain largely unknown. It is not known if results from clinical trials can be extrapolated to everyday clinical practice. We will conduct a nationwide study to investigate the risks and incidence rates of intracranial hemorrhage in users oral antithrombotic drugs in Norway from 2008 through 2014.   Methods and design The aim of this nationwide study is to investigate the incidence rates of intracranial hemorrhage requiring hospitalization in users of oral antithrombotic drugs. The study will be conducted within the approximately 4.7 million inhabitants of Norway from January 1 (st), 2008, to December 31 (st), 2014. Treatment and outcome data are obtained from the Norwegian patient registry and the Norwegian prescription database.   Trial registration number Clinicaltrials.gov (NCT02481011).
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, 7030, Norway; Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway; National Advisory Unit on Spinal Surgery, St. Olavs University Hospital, Trondheim, 7030, Norway; Norwegian Centre of Competence in Deep Brain Stimulation for Movement Disorders, St. Olavs University Hospita, Trondheim, 7030, Norway.
authors.forename: Sasha
authors.initials: S
authors.lastname: Gulati
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, 7030, Norway; Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway; National Advisory Unit on Ultrasound and Image-Guided Therapy, St. Olavs University Hospital, Trondheim, 7030, Norway.
authors.forename: Ole
authors.initials: O
authors.lastname: Solheim
authors.affiliation: Department of Endocrinology, St. Olavs University Hospital, Trondheim, 7030, Norway; Unit for Applied Clinical Research, Department of Cancer Research and Molecular Medicine,, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
authors.forename: Sven M
authors.initials: SM
authors.lastname: Carlsen
authors.affiliation: Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway; Department of Neurology, St. Olavs University Hospital, Trondheim, 7030, Norway.
authors.forename: Lise R
authors.initials: LR
authors.lastname: Øie
authors.affiliation: Norwegian Patient Registry, Trondheim, 1601, Norway.
authors.forename: Heidi
authors.initials: H
authors.lastname: Jensberg
authors.affiliation: Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway; Department of Rheumatology, St. Olavs University Hospital, Trondheim, 7030, Norway.
authors.forename: Agnete M
authors.initials: AM
authors.lastname: Gulati
authors.affiliation: Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
authors.forename: Charalampis
authors.initials: C
authors.lastname: Giannadakis
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, 7030, Norway; Department of Neurosurgery, Sahlgrenska University Hospital, Gothenburg, 413 45, Sweden; Institute of Neuroscience and Physiology, University of Gothenburg, Sahlgrenska Academy, Gothenburg, 413 90, Sweden.
authors.forename: Asgeir S
authors.initials: AS
authors.lastname: Jakola
authors.affiliation: Unit for Applied Clinical Research, Department of Cancer Research and Molecular Medicine,, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
authors.forename: Øyvind
authors.initials: Ø
authors.lastname: Salvesen
keywords: Drug-Related Side Effects and Adverse Reactions; Hematoma; Intracranial; Stroke; Subdural