title: Reliability of intracerebral hemorrhage classification systems: A systematic review.
abstract: Accurately distinguishing non-traumatic intracerebral hemorrhage (ICH) subtypes is important since they may have different risk factors, causal pathways, management, and prognosis. We systematically assessed the inter- and intra-rater reliability of ICH classification systems.
  
  
  
  We sought all available reliability assessments of anatomical and mechanistic ICH classification systems from electronic databases and personal contacts until October 2014. We assessed included studies' characteristics, reporting quality and potential for bias; summarized reliability with kappa value forest plots; and performed meta-analyses of the proportion of cases classified into each subtype.
  
  
  
  We included 8 of 2152 studies identified. Inter- and intra-rater reliabilities were substantial to perfect for anatomical and mechanistic systems (inter-rater kappa values: anatomical 0.78-0.97 [six studies, 518 cases], mechanistic 0.89-0.93 [three studies, 510 cases]; intra-rater kappas: anatomical 0.80-1 [three studies, 137 cases], mechanistic 0.92-0.93 [two studies, 368 cases]). Reporting quality varied but no study fulfilled all criteria and none was free from potential bias. All reliability studies were performed with experienced raters in specialist centers. Proportions of ICH subtypes were largely consistent with previous reports suggesting that included studies are appropriately representative.
  
  
  
  Reliability of existing classification systems appears excellent but is unknown outside specialist centers with experienced raters. Future reliability comparisons should be facilitated by studies following recently published reporting guidelines.
authors.affiliation: Centre for Clinical Brain Sciences, University of Edinburgh, UK.
authors.forename: Kristiina
authors.initials: K
authors.lastname: Rannikmäe
authors.affiliation: Centre for Clinical Brain Sciences, University of Edinburgh, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Woodfield
authors.affiliation: The George Institute for Global Health, Royal Prince Alfred Hospital and the University of Sydney, Australia.
authors.forename: Craig S
authors.initials: CS
authors.lastname: Anderson
authors.affiliation: Stroke Research Group, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, UK.
authors.forename: Andreas
authors.initials: A
authors.lastname: Charidimou
authors.affiliation: Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand.
authors.forename: Pipat
authors.initials: P
authors.lastname: Chiewvit
authors.affiliation: Department of Neurology, Massachusetts General Hospital, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Greenberg
authors.affiliation: Stroke Center and Department of Neurology, National Taiwan University Hospital, Taiwan.
authors.forename: Jiann-Shing
authors.initials: JS
authors.lastname: Jeng
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, Finland Departments of Medicine and the Florey, Royal Melbourne Hospital, University of Melbourne, Australia.
authors.forename: Atte
authors.initials: A
authors.lastname: Meretoja
authors.affiliation: Department of Neurology, Städtisches Klinikum Ludwigshafen, Germany.
authors.forename: Frederic
authors.initials: F
authors.lastname: Palm
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Putaala
authors.affiliation: Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands.
authors.forename: Gabriel Je
authors.initials: GJ
authors.lastname: Rinkel
authors.affiliation: Department of Neurology, Massachusetts General Hospital, USA Center for Human Genetic Research, Massachusetts General Hospital, USA Program in Medical and Population Genetics, Broad Institute, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rosand
authors.affiliation: Center for Human Genetic Research, Massachusetts General Hospital, USA.
authors.forename: Natalia S
authors.initials: NS
authors.lastname: Rost
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, Finland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Strbian
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, Finland Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Sweden Department of Neurology, Sahlgrenska University Hospital, Sweden.
authors.forename: Turgut
authors.initials: T
authors.lastname: Tatlisumak
authors.affiliation: Department of Neurology, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University, Taiwan.
authors.forename: Chung-Fen
authors.initials: CF
authors.lastname: Tsai
authors.affiliation: Department of Neurology, Leiden University Medical Center, The Netherlands.
authors.forename: Marieke Jh
authors.initials: MJ
authors.lastname: Wermer
authors.affiliation: Stroke Research Group, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, UK.
authors.forename: David
authors.initials: D
authors.lastname: Werring
authors.affiliation: Stroke Center and Department of Neurology, National Taiwan University Hospital, Taiwan.
authors.forename: Shin-Joe
authors.initials: SJ
authors.lastname: Yeh
authors.affiliation: Centre for Clinical Brain Sciences, University of Edinburgh, UK.
authors.forename: Rustam
authors.initials: R
authors.lastname: Al-Shahi Salman
authors.affiliation: Centre for Clinical Brain Sciences, University of Edinburgh, UK Institute for Genetics and Molecular Medicine, University of Edinburgh, UK UK Biobank, UK cathie.sudlow@ed.ac.uk.
authors.forename: Cathie Lm
authors.initials: CL
authors.lastname: Sudlow
mesh_terms: D002543:Cerebral Hemorrhage / Q000145:classification* / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D015203:Reproducibility of Results
keywords: Cerebral hemorrhage; cerebrovascular disorders; classification system; reliability; reproducibility of results; systematic review