Follow-up after pH-metry and pH impedance in pediatric gastroesophageal reflux disease

It is unclear how diagnostic tests for gastroesophageal reflux disease (GERD) in children relate to the course of symptoms during follow-up. 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. 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. 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