title: improving interrater agreement about brain microbleeds: development of the Brain Observer MicroBleed Scale (BOMBS).
abstract: OBJECTIVE
  If the diagnostic and prognostic significance of brain microbleeds (BMBs) are to be investigated and used for these purposes in clinical practice, observer variation in BMB assessment must be minimized.
  
  
  METHODS
  Two doctors used a pilot rating scale to describe the number and distribution of BMBs (round, low-signal lesions, <10 mm diameter on gradient echo MRI) among 264 adults with stroke or TIA. They were blinded to clinical data and their counterpart's ratings. Disagreements were adjudicated by a third observer, who informed the development of a new Brain Observer MicroBleed Scale (BOMBS), which was tested in a separate cohort of 156 adults with stroke.
  
  
  RESULTS
  In the pilot study, agreement about the presence of >/=1 BMB in any location was moderate (kappa=0.44; 95% CI, 0.32-0.56), but agreement was worse in lobar locations (kappa=0.44; 95% CI, 0.30-0.58) than in deep (kappa=0.62; 95% CI, 0.48-0.76) or posterior fossa locations (kappa=0.66; 95% CI, 0.47-0.84). Using BOMBS, agreement about the presence of >/=1 BMB improved in any location (kappa=0.68; 95% CI, 0.49-0.86) and in lobar locations (kappa=0.78; 95% CI, 0.60-0.97).
  
  
  CONCLUSIONS
  Interrater reliability concerning the presence of BMBs was moderate to good, and could be improved with the use of the BOMBS rating scale, which takes into account the main sources of interrater disagreement identified by our pilot scale.
authors.affiliation: Division of Clinical Neurosciences, Western General Hospital, Edinburgh EH4 2XU, UK.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Cordonnier
authors.forename: Gillian M
authors.initials: GM
authors.lastname: Potter
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Jackson
authors.forename: Fergus
authors.initials: F
authors.lastname: Doubal
authors.forename: Sarah
authors.initials: S
authors.lastname: Keir
authors.forename: Cathie L M
authors.initials: CL
authors.lastname: Sudlow
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
authors.forename: Rustam
authors.initials: R
authors.lastname: Al-Shahi Salman
mesh_terms: D000368:Aged; D001160:Arterioles / Q000473:pathology* / Q000503:physiopathology; D001921:Brain / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology; D002545:Brain Ischemia / Q000150:complications; D002536:Cerebral Arteries / Q000473:pathology* / Q000503:physiopathology; D002540:Cerebral Cortex / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D015331:Cohort Studies; D003951:Diagnostic Errors / Q000517:prevention & control; D005260:Female; D006801:Humans; D020300:Intracranial Hemorrhages / Q000473:pathology* / Q000503:physiopathology; D002546:Ischemic Attack, Transient / Q000150:complications; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards*; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications