title: Sensitivity and specificity of the Gastrointestinal Short Form Questionnaire in diagnosis of gastroesophageal reflux disease.
abstract: BACKGROUND
  Gastrointestinal Short Form Questionnaire (GSFQ) is a questionnaire for gastroesophageal reflux disease (GERD) diagnosis, with a version in Spanish language, not yet compared to an objective test.
  
  
  OBJECTIVE
  To establish GSFQ diagnostic performance against 24-hour pH monitoring carried out in two tertiary care hospitals.
  
  
  METHODS
  Consecutive adult patients with typical GERD symptoms (heartburn, regurgitation) referred for pH monitoring fulfilled the GSFQ (score range 0-30, proportional to probability of GERD). Diagnosis of GERD was established when acid exposure time in distal esophagus was superior to 4.5% or symptom association probability was greater than 95%. Receiver-operator characteristic (ROC) curves were calculated and best cut-off score determined, with corresponding sensitivity, specificity and likelihood ratios (LR) (95% confidence interval for each).
  
  
  RESULTS
  One hundred and fifty-two patients were included (59.9% women, age 47.9 ± 13.9; 97.4% heartburn; 71.3% regurgitation). pH monitoring was abnormal in 65.8%. Mean GSFQ score was 11.2 ± 6. Area under ROC was 56.5% (47.0-65.9%). Optimal cut-off score was 13 or greater: sensitivity 40% (30.3-50.3%), specificity 71.2% (56.9-82.9%), positive LR 1.39 (0.85-2.26) and negative LR 0.84 (0.67-1.07). Exclusion of questions 1 and 3 of the original GSFQ, easily interpreted as referred to dyspepsia and not GERD, improved only marginally the diagnostic performance: AUROC 59.1%.
  
  
  CONCLUSIONS
  The GSFQ does not predict results of pH monitoring in patients with typical symptoms in a tertiary care setting.
authors.affiliation: Aparato Digestivo, Hospital Ramón y Cajal, Madrid, España.
authors.forename: Carlos
authors.initials: C
authors.lastname: Teruel Sánchez-Vegazo
authors.affiliation: Gastroenterología y Hepatología, Hospital Ramón y Cajal, Madrid.
authors.forename: Vicenta
authors.initials: V
authors.lastname: Faro Leal
authors.affiliation: Servicio de Bioestadística Clínica, Hospital Ramón y Cajal.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Muriel García
authors.affiliation: Aparato Digestivo, Hospital Madrid Norte Sanchinarro, Madrid.
authors.forename: Norberto
authors.initials: N
authors.lastname: Mañas Gallardo
mesh_terms: D000328:Adult; D000368:Aged; D050782:Esophageal pH Monitoring; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D012016:Reference Values; D015203:Reproducibility of Results; D013030:Spain; D011795:Surveys and Questionnaires
chemical_list: D054328:Proton Pump Inhibitors