Interobserver and intraobserver variability in pH-impedance analysis between 10 experts and automated analysis

Area of Science:

• Gastroenterology
• Pediatric Medicine
• Diagnostic Technology

Background:

• Accurate interpretation of pH-multichannel intraluminal impedance (MII) is crucial for diagnosing gastroesophageal reflux (GER).
• Variability in expert interpretation can impact clinical decision-making.

Purpose of the Study:

• To assess interobserver and intraobserver variability in expert interpretation of pediatric 24-hour pH-impedance tracings.
• To evaluate the accuracy of automated analysis (AA) in detecting GER episodes compared to expert consensus.

Main Methods:

• Ten pediatric 24-hour pH-impedance tracings were analyzed by 10 international experts and by AA.
• Detection of liquid, mixed, and gas gastroesophageal reflux (GER) events was compared.
• Intraobserver agreement was assessed in three experts after a 3-5 month interval.

Main Results:

• Moderate agreement was observed among experts for GER detection (Cohen's kappa [κ] = 0.46), with only 42% of events identified by the majority.
• Detection of the total number of GER events per study showed higher consistency (Intraclass coefficient = 0.84).
• Automated analysis demonstrated high sensitivity (94%) but moderate specificity (74%) compared to expert consensus. Agreement for gas GER was poor (κ = 0.11).

Conclusions:

• Expert interobserver agreement in pH-impedance analysis for GER is moderate, highlighting potential diagnostic inconsistencies.
• Automated analysis shows promise due to its reproducibility, but requires further refinement to improve specificity before widespread clinical adoption.