title: Interobserver and intraobserver variability in pH-impedance analysis between 10 experts and automated analysis.
abstract: OBJECTIVE
  To determine interobserver and intraobserver variability in pH-impedance interpretation between experts and accuracy of automated analysis (AA).
  
  
  METHODS
  Ten pediatric 24-hour pH-impedance tracings were analyzed by 10 observers from 7 world groups and with AA. Detection of gastroesophageal reflux (GER) episodes was compared between observers and AA. Intraobserver agreement was assessed in 3 observers after 3 to 5 months.
  
  
  RESULTS
  Overall, 1242 liquid and mixed GER events were detected, 490 (42%) were scored by the majority of observers, yielding moderate agreement (Cohen's kappa [κ] = 0.46). Intraclass co-efficient for numbers of GER per study was 0.84 (P < .001). AA has 94% sensitivity rate and 74% specificity rate compared with majority consensus (≥6 observers). Agreement for gas GER was poor (κ = 0.11). Intraobserver agreement was κ = 0.49, κ = 0.71, and κ = 0.85 in 3 observers.
  
  
  CONCLUSIONS
  Interobserver agreement in combined pH-multichannel intraluminal impedance analysis in experts is moderate; only 42% of GER episodes were detected by the majority of observers. Detection of total GER numbers is more consistent. Considering these poor outcomes, AA seems favorable compared with manual analysis because of its reproducibility. However, the lower specificity rate suggests the need for refinement of AA before widespread use can be advocated.
authors.affiliation: Department of Pediatric Gastroenterology and Nutrition, Emma Kinderziekenhuis, Academic Medical Centre, Amsterdam, The Netherlands. c.m.loots@amc.nl
authors.forename: Clara M
authors.initials: CM
authors.lastname: Loots
authors.forename: Michiel P
authors.initials: MP
authors.lastname: van Wijk
authors.forename: Kathleen
authors.initials: K
authors.lastname: Blondeau
authors.forename: Kasper
authors.initials: K
authors.lastname: Dalby
authors.forename: Laura
authors.initials: L
authors.lastname: Peeters
authors.forename: Rachel
authors.initials: R
authors.lastname: Rosen
authors.forename: Silvia
authors.initials: S
authors.lastname: Salvatore
authors.forename: Tobias G
authors.initials: TG
authors.lastname: Wenzl
authors.forename: Yvan
authors.initials: Y
authors.lastname: Vandenplas
authors.forename: Marc A
authors.initials: MA
authors.lastname: Benninga
authors.forename: Taher I
authors.initials: TI
authors.lastname: Omari
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D050782:Esophageal pH Monitoring; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D007223:Infant; D015588:Observer Variation; D012680:Sensitivity and Specificity