A retrospective hospital-based chart review will be conducted at eight different hospitals covering all four health regions and more than 3 million inhabitants in Norway. These eight hospitals are Akershus University Hospital, Haukeland University Hospital. Oslo University Hospital (Ullevål), Sørlandet Hospital Kristiansand, Drammen Hospital, St.Olavs Hospital, Nordlandsykehuset Bodø, University Hospital of North Norway.~A search will be made in the clinical database for patients with the relevant diagnosis of CVT in the period between January 1, 2010, and December 31, 2019. Data from hospital charts will be linked with data from Statistics Norway (SSB), FD-Trygd, and Norwegian Prescription Database (NorPD). Using this combination of clinical data and health registries will make it possible to describe risk factors, clinical and radiological presentation, treatment and short-term outcome in a large Norwegian CVT cohort.~Further, data from hospitals will be linked with data from SSB, FD-Trygd, NorPD, Norwegian Patient Registry (NPR) and Cause of Death Registry (DÅR) up to five years after CVT. Using this methodology will make it possible to investigate overall long-term prognosis and outcomes in terms of mortality, health care utilisation, medication use and working situation up to five years after CVT in a large Norwegian cohort.~Lastly, a prospective follow-up study will include patients that have been diagnosed with CVT at the NoCVT hospitals during 2015-2019. By combining the collected data from the retrospective hospital chart review with the new follow-up interviews and self-reported questionnaires it will be possible to describe quality of life, vocational outcomes, psychological distress, depression, insomnia and disease-related disability in CVT.
The NoCVT study will investigate CVT (2010-2019) in a large Norwegian population (> 3 millions) using several approaches combining existing health registries, clinical databases and new prospectively collected clinical data to explore epidemiology, risk factors, diagnostics, treatment, and the long-term prognosis of CVT.