Development of the Dietitian Integrated Evaluation Tool for Gluten-free Diets (DIET-GFD)

Objectives: Celiac disease (CD) treatment involves a gluten-free diet (GFD). There is no standardized tool for dietitians to objectively grade GFD adherence. This study aimed to develop a standardized tool for dietitians to evaluate and communicate GFD adherence.

Methods: Participants were recruited from the Manitoba Celiac Disease Cohort. Using a consensus process, an expert panel of gastroenterologists, dietitians, clinical health psychologists, and persons with CD developed the Dietitian Integrated Evaluation Tool for Gluten-free Diets (DIET-GFD). Two dietitians performed duplicate assessments of 27 newly diagnosed participants who had been advised to follow a GFD. The global adherence scale was further revised after panel discussions of the cases where there was uncertainty or discordance on dietitian ratings. Subsequently, the scoring system was evaluated using duplicate assessments of an additional 37 participants with CD. Interrater agreement was assessed using square-weight Cohen's kappa.

Results: The DIET-GFD includes features related to frequency and quantity of gluten ingestion based on self-reporting and food frequency evaluation, shopping and dining habits, how and where food is prepared and consumed, eating behaviors, and label reading skills. The DIET-GFD global assessment is reported using a 10-point ordinal descriptive scale, ranging from 1 (takes few precautions and regularly eats gluten) to 10 (no gluten in kitchen and rarely eats food prepared outside the home). The kappa of DIET-GFD global assessment was 0.845, which indicates excellent agreement.

Conclusions: DIET-GFD is a useful tool for dietitians to evaluate GFD adherence. Further studies are needed to confirm that the score from the DIET-GFD is reliable across various settings.