title: A validated disease-specific symptom index for adults with celiac disease.
abstract: OBJECTIVE
  Although the incidence of celiac disease (CD) is increasing, studies have been hampered by the lack of validated outcome measures. We sought to create a disease-specific Celiac Symptom Index (CSI) to reliably assess relevant symptoms.
  
  
  METHODS
  A 36-item questionnaire was created after design by an expert committee and review/revision by patient focus groups. The survey, covering domains of CD-related symptoms and general health, was initially administered to 154 individuals with biopsy-proven CD; immunoglobulin (Ig)A tissue transglutaminase titers were determined, and gluten-free diet adherence was evaluated by a dietitian. The questionnaire was then revised to exclude questions with poor test characteristics and administered to a second, independent group of 52 individuals, to ensure validity.
  
  
  RESULTS
  The subscales of "specific symptoms" and "general health" had excellent psychometric qualities that consisted of 11 and 5 items, respectively. The additive score based on these items was correlated with current general health, as measured by a visual analog scale and short form 36 general health subscale (P < or = .001 for both), as well as degree of adherence to the gluten-free diet (P = .008), lending external validity to the CSI. The resulting 16 questions make up the first CD-specific symptom index.
  
  
  CONCLUSIONS
  The CSI allows for disease-specific monitoring of symptoms as an independent outcome measure or as part of a surrogate for disease activity in individuals with CD. The CSI might be an important tool for future clinical CD research.
authors: Celiac Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA. dleffler@caregroup.harvard.edu
authors: Daniel A
authors: DA
authors: Leffler
authors: Melinda
authors: M
authors: Dennis
authors: Jessica
authors: J
authors: Edwards George
authors: Shailaja
authors: S
authors: Jamma
authors: E Francis
authors: EF
authors: Cook
authors: Detlef
authors: D
authors: Schuppan
authors: Ciaran P
authors: CP
authors: Kelly
mesh_terms: D000328:Adult; D002446:Celiac Disease / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D055050:Diet, Gluten-Free; D005260:Female; D017144:Focus Groups; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
chemical_list: D007070:Immunoglobulin A