title: A simple validated gluten-free diet adherence survey for adults with celiac disease.
abstract: OBJECTIVE
  Celiac disease is an increasingly prevalent disorder. To monitor response to treatment in clinical and research settings, it is essential to accurately measure gluten-free diet (GFD) adherence in a standardized manner. The aim of this study was to develop a valid and reliable Celiac Dietary Adherence Test (CDAT).
  
  
  METHODS
  Items and domains believed to be essential for successful GFD adherence were used to develop an 85-item survey with input from patient focus groups. The survey was administered to 200 individuals with biopsy-proven celiac disease who underwent standardized dietician evaluation (SDE) and serologic testing.
  
  
  RESULTS
  Of the initial 85 items, 41 were correlated highly with the SDE (P < .01). Responses for all 200 participants for the 41 items were entered into a single database. Computer-generated randomization produced a derivation cohort of 120 subjects and a validation cohort of 80. By using the derivation cohort, a 7-item questionnaire was developed using logistic regression. The additive score based on these items was correlated highly with the SDE in both the derivation and validation cohorts (P < .001) and performed significantly better than immunoglobulin A tissue transglutaminase titers in receiver operating characteristic curve analysis with areas under the curve of 0.830 and 0.652, respectively.
  
  
  CONCLUSIONS
  The CDAT is a clinically relevant, easily administered, 7-item instrument that allows for standardized evaluation of GFD adherence and is superior to tissue transglutaminase serology. The CDAT may be useful in both research and clinical settings.
authors.affiliation: Celiac Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA. dleffler@caregroup.harvard.edu
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Leffler
authors.forename: Melinda
authors.initials: M
authors.lastname: Dennis
authors.forename: Jessica B
authors.initials: JB
authors.lastname: Edwards George
authors.forename: Shailaja
authors.initials: S
authors.lastname: Jamma
authors.forename: Suma
authors.initials: S
authors.lastname: Magge
authors.forename: Earl F
authors.initials: EF
authors.lastname: Cook
authors.forename: Detlef
authors.initials: D
authors.lastname: Schuppan
authors.forename: Ciaran P
authors.initials: CP
authors.lastname: Kelly
mesh_terms: D000328:Adult; D002446:Celiac Disease / Q000628:therapy*; D003625:Data Collection / Q000379:methods*; D055050:Diet, Gluten-Free; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011897:Random Allocation