For a long time, no Swedish patient-reported outcome questionnaires for eosinophilic esophagitis have been available, which has limited the assessment of the disease. Recently, the Eosinophilic Esophagitis Activity Index (EEsAI) questionnaire was translated to Swedish and validated for the assessment of symptom severity in patients with eosinophilic esophagitis. Now, a second questionnaire, the Swedish Watson Dysphagia Scale (S-WDS), has been validated for this patient group as well. The S-WDS has been used to assess dysphagia in patients with eosinophilic esophagitis in Sweden before, but without being validated for this purpose. The S-WDS has been widely appreciated by the patients and is both easy to fill out and to interpret. This makes the S-WDS an ideal instrument for assessing symptoms of dysphagia related to eosinophilic esophagitis in the clinic. The validation of the S-WDS was done with 97 Swedish adult patients with eosinophilic esophagitis and 97 controls without dysphagia. The study participants filled out both the S-WDS and the Swedish EEsAI and provided a self-assessment score of disease severity ranging from 0-10. The reliability of the S-WDS was evaluated using Cronbach’s alpha, Pearson correlation of items and total score, and a test-retest analysis (n=29). The Cronbach’s alpha of the S-WDS was 0.77 and all items within the S-WDS demonstrated moderate to strong correlation to the final S-WDS score (r=0.40-0.81), indicative of sufficient reliability of the instrument. The results from the test-retest analysis reflected excellent reliability with an intraclass correlation coefficient of 0.85. The validity of the S-WDS was then investigated using Spearman correlations between the S-WDS items and the domains of the Swedish EEsAI questionnaire and the provided self-assessment score. These tests revealed adequate validity of the questionnaire, the S-WDS score correlated moderately with the self-assessment score and with 4/6 S-EEsAI domains, and strongly with the remaining two domains. Finally, the resulting S-WDS scores of the patient group were compared to the scores obtained by the control group and the scores were significantly different (P<0.001). The validation of the S-WDS has shown that it is a valid and appropriate questionnaire for the assessment of dysphagia in patients with eosinophilic esophagitis. The access to two Swedish instruments specifically validated for eosinophilic esophagitis will enable better assessment of the disease, benefacting both patients and clinicians.

Table 1: Layout of the items in the Swedish Watson Dysphagia Scale Result 0-45 points.

The patient answer, never (0p), sometime (0,5p) or always (1p).

The number of food (1-9) is multiplied by the answer (0, 0,5 and 1). 0 points (never any difficulties with any of the foods), 45 points (always difficulties with swallowing all the foods).

Because of my swallowing difficulties, I have trouble to:

• Drink water (item 1)
• Drink milk (item 2)
• Eat yoghurt (item 3)
• Eat jam or jelly (item 4)
• Eat omelet or mashed potatoes (item 5)
• Eat boiled vegetables, potatoes or fish (item 6)
• Eat soft white bread or pasta (item 7)
• Eat fresh fruit, e.g., apple (item 8)
• Eat meat, e.g., pork chop (item 9)

Dis Esophagus. 2022 Jan 22;doab097.doi: 10.1093/dote/doab097.