Adapting the International Dysphagia Diet Standardisation Initiative in East Asia: Feasibility study

In dysphagia, food or water cannot be delivered safely through the oral cavity to the stomach; both are treated using texture-modified food and thickened fluid. Before, each country had its own diet modifications and texture measurement standards. In 2012, the International Dysphagia Diet Standardisation Initiative (IDDSI) was developed by several countries. Owing to cultural differences, it was necessary to determine whether the IDDSI could well be applied to clinicians and patients without difficulties in East Asia countries. To evaluate the IDDSI scale to find out the difficulties applying this scale in East Asia countries to educate the clinicians and patients. In May 2021, we enrolled physicians, nurses, nutritionists, and swallowing therapists involved in dysphagia treatment at a single center in Seoul. To evaluate the degree of understanding and difficulties of adapting IDDSI to clinicians in East Asia countries, we used the 17-item questionnaire with IDDSI sample foods and foods in Asian countries. In first 7 items, we compared IDDSI with the previously used scale based on the National Dysphagia Diet (NDD). In the next 10 questions, only the IDDSI levels were answered, and the absolute values of the answer-response differences were calculated. The IDDSI showed a significantly high intraclass correlation with the previously used NDD-based scale; the coefficient was higher for the nutritionists (0.988) and swallowing therapists (0.991). When evaluating whether the IDDSI could applied well in East Asia countries, the absolute values of the answer-response differences were lower than 0.5 in majority of levels, except for Level 4. Because the IDDSI framework might successfully be applied universally regardless of food culture, a worldwide standard for food rheology in dysphagia treatment might be possible.