title: Comparison of upper gastrointestinal contrast studies and pH/impedance tests for the diagnosis of childhood gastro-oesophageal reflux.
abstract: BACKGROUND
  The upper gastrointestinal (UGI) contrast study is used in the assessment of children with gastro-oesophageal reflux (GOR) and for detection of structural anomalies. The pH study is more sensitive than the UGI study for the diagnosis of GOR. The pH study has been replaced by the pH/impedance test, which detects both acid and nonacid reflux.
  
  
  OBJECTIVE
  To compare the UGI contrast study with the pH/impedance test for the diagnosis of GOR in children.
  
  
  METHODS
  We retrospectively reviewed consecutive records of children investigated for GOR from October 2008 to February 2010, and compared the findings of UGI studies with those of pH/impedance tests.
  
  
  RESULTS
  The UGI studies revealed GOR in 116 of 579 children (20%). Of the children undergoing a UGI study, 66 also underwent a pH/impedance test. Using the pH/impedance tests as the reference for GOR, UGI had a sensitivity of 42.8% and a negative predictive value of 24%. There was no significant correlation (P > 0.05) between the reflux index and the number of reflux episodes in the pH/impedance tests and height of reflux in the UGI study. There were low incidences of malrotation (0.9%), hiatus hernia (1%) and delayed gastric emptying (0.4%).
  
  
  CONCLUSIONS
  The UGI study had low sensitivity for the diagnosis of GOR and low yield for the diagnosis of structural anomalies.
authors.affiliation: Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK. e.macharia@ucl.ac.uk
authors.forename: Eva W
authors.initials: EW
authors.lastname: Macharia
mesh_terms: D000293:Adolescent; D001466:Barium Sulfate; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D017097:Electric Impedance; D050782:Esophageal pH Monitoring; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D007223:Infant; D007472:Iohexol; D008297:Male; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D001466:Barium Sulfate; D007472:Iohexol