title: Development and field testing of a novel patient-reported outcome measure of dysphagia in patients with eosinophilic esophagitis.
abstract: BACKGROUND
  Dysphagia is the hallmark of eosinophilic esophagitis (EoE), but no validated dysphagia instruments in this population exist.
  
  
  OBJECTIVE
  To develop and field test a patient-reported outcome (PRO) for dysphagia in subjects with EoE.
  
  
  METHODS
  This was a multi-centre/multi-phase prospective study. The first phase developed a dysphagia questionnaire using qualitative methods. The second phase was a 30-day field trial to test the instrument and assess content validity. Adolescents and adults with EoE, active symptoms of dysphagia and oesophageal eosinophilia (≥15 eosinophils per high-power field) were enrolled. Solid-food-avoidance days, dysphagia days and actions taken to get relief were recorded. A dysphagia score was calculated and compared to the Straumann Dysphagia Instrument (SDI).
  
  
  RESULTS
  Ten adolescents and 10 adults were included in the first phase and the Dysphagia Symptom Questionnaire (DSQ), a three-item daily electronic diary, was developed. In the second phase, 35 subjects finished the field trial (18 adults, 17 adolescents, mean age 24, 54% male, 95% white, 54% currently on topical corticosteroids). The median number of dysphagia days per week was 2 for adolescents vs. 4 for adults (P < 0.001), and 2 for those on topical steroids vs. 4 for those not on topical steroids (P < 0.001). The DSQ score strongly correlated with the number of dysphagia days (R = 0.96; P < 0.001) and the SDI (R = 0.77; P < 0.001).
  
  
  CONCLUSIONS
  The DSQ, a three-question patient-reported outcome, was successfully developed and field tested. The DSQ had content validity and the score accurately measured dysphagia frequency and intensity. The Dysphagia Symptom Questionnaire is suitable for use in clinical trials of EoE patients with dysphagia.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7080, USA. edellon@med.unc.edu
authors.forename: E S
authors.initials: ES
authors.lastname: Dellon
authors.forename: A-M
authors.initials: AM
authors.lastname: Irani
authors.forename: M R
authors.initials: MR
authors.lastname: Hill
authors.forename: I
authors.initials: I
authors.lastname: Hirano
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003680:Deglutition Disorders / Q000175:diagnosis*; D059026:Diagnostic Self Evaluation; D057765:Eosinophilic Esophagitis / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult