title: Intracranial Hemorrhage After Ischemic Stroke: Incidence, Time Trends, and Predictors in a Swedish Nationwide Cohort of 196 765 Patients.
abstract: BACKGROUND
  Epidemiological data on the risk of intracranial hemorrhage (ICrH) after ischemic stroke are sparse. The aims of this study were to describe incidence, trends over time, and predictors of ICrH within 1 year after ischemic stroke.
  
  
  RESULTS
  All patients registered in the Swedish stroke register Riksstroke for 1998 to 2009 were included (n=196 765), and data were combined with the National Patient Register to identify ICrH occurrence. A matched reference population was obtained. Incidence rates and cumulative incidences were calculated. Multivariable regression analyses were used to identify predictors. Analyses were performed separately for the first 30 days and days 31 to 365 after ischemic stroke. The incidence rate was 1.97% per year at risk for the first year (0.13% in the reference population) and 0.85% excluding the first 30 days. Over time, the cumulative incidence increased the first 30 days but decreased over days 31 to 365. Thrombolysis, previous ICrH, atrial fibrillation, and male sex were associated with increased risk of ICrH during the first 30 days. Previous ICrH, increasing age, and male sex were associated with increased risk during days 31 to 365. Statins and antithrombotic treatment did not independently predict ICrH occurrence.
  
  
  CONCLUSIONS
  The incidence of ICrH within 1 year after ischemic stroke was ≈2% per year at risk, about 15 times higher compared with the reference population. Over the study period, ICrH risk increased within the first 30 days but decreased thereafter. Previous ICrH, thrombolysis, and male sex affected the risk, whereas an increased use of antithrombotic treatments and statins did not.
authors.affiliation: From the Department of Public Health and Clinical Medicine, Unit of Research, Education and Development - Östersund, Umeå University, Umeå, Sweden. Joachim.ogren@regionjh.se.
authors.forename: Joachim
authors.initials: J
authors.lastname: Ögren
authors.affiliation: From the Department of Public Health and Clinical Medicine, Unit of Research, Education and Development - Östersund, Umeå University, Umeå, Sweden.
authors.forename: Anna-Lotta
authors.initials: AL
authors.lastname: Irewall
authors.affiliation: From the Department of Public Health and Clinical Medicine, Unit of Research, Education and Development - Östersund, Umeå University, Umeå, Sweden.
authors.forename: Lisa
authors.initials: L
authors.lastname: Bergström
authors.affiliation: From the Department of Public Health and Clinical Medicine, Unit of Research, Education and Development - Östersund, Umeå University, Umeå, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mooe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000150:complications*; D002545:Brain Ischemia / Q000150:complications* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D020300:Intracranial Hemorrhages / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors
keywords: epidemiology; intracerebral hemorrhage; intracranial hemorrhage; regression analysis; risk; stroke