Brief Article
Copyright ©2010 Baishideng. All rights reserved.
World J Gastroenterol. May 21, 2010; 16(19): 2401-2406
Published online May 21, 2010. doi: 10.3748/wjg.v16.i19.2401
Disagreement between symptom-reflux association analysis parameters in pediatric gastroesophageal reflux disease investigation
Samuel C Lüthold, Mascha K Rochat, Peter Bähler
Samuel C Lüthold, Division of Gastroenterology, Departement of Pediatrics, Hospital of Fribourg, CH-1708 Fribourg, Switzerland
Mascha K Rochat, Asthma and Allergy Research Group, University of Munich, Lindwurmstrasse 4, D 80337 Munich, Germany
Peter Bähler, Division of Gastroenterology, Departement of Pediatrics, Hospital of Fribourg, CH-1708 Fribourg, Switzerland
Author contributions: Lüthold SC designed the research and wrote the paper; Rochat MK analyzed the data and was involved in editing the manuscript; Bähler P provided the data and was involved in editing the manuscript.
Correspondence to: Samuel C Lüthold, MD, Division of Gastroenterology, Departement of Pediatrics, Hospital of Fribourg, CH-1708 Fribourg, Switzerland. samuel_luethold@bluewin.ch
Telephone: +41-26-4267405 Fax: +41-26-4267404
Received: January 13, 2010
Revised: March 16, 2010
Accepted: March 23, 2010
Published online: May 21, 2010
Abstract

AIM: To assess the agreement within 3 commonly used symptom-reflux association analysis (SAA) parameters investigating gastroesophageal reflux disease (GERD) in infants.

METHODS: Twenty three infants with suspected GERD were included in this study. Symptom index (SI), Symptom sensitivity index (SSI) and symptom association probability (SAP) related to cough and irritability were calculated after 24 h combined pH/multiple intraluminal impedance (MII) monitoring. Through defined cut-off values, SI, SSI and SAP values are differentiated in normal and abnormal, whereas abnormal values point towards gastroesophageal reflux (GER) as the origin of symptoms. We analyzed the correlation and the concordance of the diagnostic classification of these 3 SAA parameters.

RESULTS: Evaluating the GER-irritability association, SI, SSI and SAP showed non-identical classification of normal and abnormal cases in 39.2% of the infants. When irritability was taken as a symptom, there was only a poor inter-parameter association between SI and SSI, and between SI and SAP (Kendall’s tau b = 0.37, P < 0.05; Kendall’s tau b = 0.36, P < 0.05, respectively). Evaluating the GER-cough association, SI, SSI and SAP showed non-identical classification of normal and abnormal cases in 52.2% of the patients. When cough was taken as a symptom, only SI and SSI showed a poor inter-parameter association (Kendall’s tau b = 0.33, P < 0.05).

CONCLUSION: In infants investigated for suspected GERD with pH/MII-monitoring, SI, SSI and SAP showed a poor inter-parameter association and important disagreements in diagnostic classification. These limitations must be taken into consideration when interpreting the results of SAA in infants.

Keywords: Gastroesophageal reflux disease; Infant; Symptom-reflux association analysis; Intraluminal impedance monitoring; pH