title: Agreement in the scoring of respiratory events and sleep among international sleep centers.
abstract: OBJECTIVE
  The American Academy of Sleep Medicine (AASM) guidelines for polysomnography (PSG) scoring are increasingly being adopted worldwide, but the agreement among international centers in scoring respiratory events and sleep stages using these guidelines is unknown. We sought to determine the interrater agreement of PSG scoring among international sleep centers.
  
  
  METHODS
  Prospective study of interrater agreement of PSG scoring.
  
  
  METHODS
  Nine center-members of the Sleep Apnea Genetics International Consortium (SAGIC).
  
  
  RESULTS
  Fifteen previously recorded deidentified PSGs, in European Data Format, were scored by an experienced technologist at each site after they were imported into the locally used analysis software. Each 30-sec epoch was manually scored for sleep stage, arousals, apneas, and hypopneas using the AASM recommended criteria. The computer-derived oxygen desaturation index (ODI) was also recorded. The primary outcome for analysis was the intraclass correlation coefficient (ICC) of the apnea-hypopnea index (AHI). The ICCs of the respiratory variables were: AHI = 0.95 (95% confidence interval: 0.91-0.98), total apneas = 0.77 (0.56-0.87), total hypopneas = 0.80 (0.66-0.91), and ODI = 0.97 (0.93-0.99). The kappa statistics for sleep stages were: wake = 0.78 (0.77-0.79), nonrapid eye movement = 0.77 (0.76-0.78), N1 = 0.31 (0.30-0.32), N2 = 0.60 (0.59-0.61), N3 = 0.67 (0.65-0.69), and rapid eye movement = 0.78 (0.77-0.79). The ICC of the arousal index was 0.68 (0.50-0.85).
  
  
  CONCLUSIONS
  There is strong agreement in the scoring of respiratory events among the SAGIC centers. There is also substantial epoch-by-epoch agreement in scoring sleep variables. Our results suggest that centralized scoring of PSGs may not be necessary in future research collaboration among international sites where experienced, well-trained scorers are involved.
authors.affiliation: Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA. magalang.1@osu.edu
authors.forename: Ulysses J
authors.initials: UJ
authors.lastname: Magalang
authors.forename: Ning-Hung
authors.initials: NH
authors.lastname: Chen
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cistulli
authors.forename: Annette C
authors.initials: AC
authors.lastname: Fedson
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Gíslason
authors.forename: David
authors.initials: D
authors.lastname: Hillman
authors.forename: Thomas
authors.initials: T
authors.lastname: Penzel
authors.forename: Renaud
authors.initials: R
authors.lastname: Tamisier
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
authors.forename: Gary
authors.initials: G
authors.lastname: Phillips
authors.forename: Allan I
authors.initials: AI
authors.lastname: Pack
mesh_terms: D006801:Humans; D015588:Observer Variation; D017286:Polysomnography / Q000379:methods* / Q000592:standards*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000503:physiopathology*; D012984:Software
keywords: General; polysomnography; scoring
references.citation: Int J Tuberc Lung Dis. 2007 Jan;11(1):2-11
references.pmid: 17217123
references.citation: N Engl J Med. 1993 Apr 29;328(17):1230-5
references.pmid: 8464434
references.citation: Thorax. 1996 Aug;51 Suppl 2:S65-70
references.pmid: 8869356
references.citation: J Sleep Res. 2009 Mar;18(1):74-84
references.pmid: 19250176
references.citation: N Engl J Med. 2005 Nov 10;353(19):2070-3
references.pmid: 16282183
references.citation: N Engl J Med. 2005 Nov 10;353(19):2034-41
references.pmid: 16282178
references.citation: Sleep. 2005 Apr;28(4):499-521
references.pmid: 16171294
references.citation: Sleep. 1999 Aug 1;22(5):667-89
references.pmid: 10450601
references.citation: J Thorac Dis. 2010 Sep;2(3):138-43
references.pmid: 22263035
references.citation: Biometrics. 1977 Mar;33(1):159-74
references.pmid: 843571
references.citation: J Clin Ultrasound. 2012 Jan;40(1):14-9
references.pmid: 22109854
references.citation: Chest. 2005 Jan;127(1):80-8
references.pmid: 15653966
references.citation: Thorax. 2001 Jul;56(7):508-12
references.pmid: 11413347
references.citation: Arch Intern Med. 1997 Aug 11-25;157(15):1746-52
references.pmid: 9250236
references.citation: Sleep. 1998 Nov 1;21(7):749-57
references.pmid: 11286351