Validation of a Cross-Cultural Adaptation of the M.D. Anderson Dysphagia Inventory to Canadian French (MDADI-CF).

The MDADI is a validated tool for assessing quality of life in several languages, often used for patients with head and neck cancer (HNC). It has never been translated and validated in Canadian French, which bears significantly different linguistic characteristics compared to European French. Our objective was to validate a Canadian French version of the MDADI (MDADI-CF) for HNC patients suffering from dysphagia. The MDADI-CF was developed using the translation-back-translation method. Participants were recruited from an outpatient clinic: those suffering from dysphagia secondary to HNC comprised the experimental group, while those without dysphagia comprised the control group. They were asked to complete the MDADI-CF and the SWAL-QoL, another similar questionnaire on dysphagia which has been validated in French. A subgroup of patients also received a second MDADI-CF to complete one week later. Feasibility, internal consistency, construct validity, and test-retest reliability were all assessed. 93% of patients completed the questionnaire without leaving any questions blank. Internal consistency analyses demonstrated a Cronbach's alpha > 0.7 for all subscales of the questionnaire. Convergent validity was confirmed with a high correlation between the MDADI-CF scores and French SWAL-QOL (0.91, p < 0.0001). Discriminant validity was also demonstrated by the significant difference between MDADI-CF scores of patient vs control group (93.3 vs 62.4, p < 0.0001). Test-retest reliability was demonstrated with an intraclass correlation coefficient of 0.918 on the total score between the first and second questionnaire completion. Our results demonstrate that the MDADI-CF I is valid and should be used in evaluating dysphagia in the Canadian Francophone population.