title: Follow-up after pH-metry and pH impedance in pediatric gastroesophageal reflux disease.
abstract: OBJECTIVE
  It is unclear how diagnostic tests for gastroesophageal reflux disease (GERD) in children relate to the course of symptoms during follow-up.
  
  
  METHODS
  During 1 year, all children (ages 0-18 years), who underwent pH-metry and/or pH multichannel intraluminal impedance (MII), were included after written informed consent was obtained. pH-metry and pH-MII test characteristics, such as reflux index (RI, % time that esophageal pH < 4), were obtained from the measurements. A questionnaire containing subcategories (medical history, gastrointestinal [GI] symptoms, extraesophageal symptoms, symptom burden, and therapeutic agents) was used; subjects were asked to fill the questionnaire at the time of inclusion and 3, 6, and 12 months afterward.
  
  
  RESULTS
  A total of 162 infants and 42 children were included. pH-MII was performed in 15.4% and 57.4% of infants and children, respectively. All of the other subjects underwent pH-metry. Median RI was 2.0% (interquartile range 3.4) in infants and 1.7% (interquartile range 2.3) in children. RI was considered positive in 6.8% and 12.8% of infants and children, respectively. In infants, RI at baseline was significantly associated with symptom burden at baseline and at 3 and 12 months of follow-up. RI at baseline and reported GI symptoms at 3 months were also significantly associated. In infants and children using medication, symptom burden was significantly higher compared with those not using medication. This difference was found at baseline, after 3 and 12 months.
  
  
  CONCLUSIONS
  In infants, an initial high RI is associated with persistence of GI symptoms at 3 months and a higher burden of symptoms during the course of 1 year. In children there were no such findings.
authors.affiliation: *Department of Pediatric Gastroenterology and Nutrition, Emma Children's Hospital AMC, Amsterdam, The Netherlands †Department of Pediatric Gastroenterology and Nutrition, UZ Brussels, Brussels, Belgium.
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: van der Pol
authors.forename: Marloes
authors.initials: M
authors.lastname: van den Ouweland
authors.forename: Clara M
authors.initials: CM
authors.lastname: Loots
authors.forename: Yvan
authors.initials: Y
authors.lastname: Vandenplas
authors.forename: Marc A
authors.initials: MA
authors.lastname: Benninga
authors.forename: Michiel P
authors.initials: MP
authors.lastname: van Wijk
mesh_terms: D002675:Child, Preschool; D017097:Electric Impedance; D050782:Esophageal pH Monitoring; D005260:Female; D005500:Follow-Up Studies; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013997:Time Factors