Assessing Dysphagia in Head and Neck Cancer Patients: Validation and Cultural Adaptation of the Thai M.D. Anderson Dysphagia Inventory (TH-MDADI)

Objective: The validation study of the Thai version of the M.D. Anderson Dysphagia Inventory (TH-MDADI) addresses a critical gap in head and neck cancer (HNC) care in Thailand. At leading institutions like Siriraj Hospital, patient-reported outcomes have been historically neglected, with care primarily focusing on routine medical services. This study aimed to validate the TH-MDADI to enhance dysphagia assessment and to promote patient-centered care. Materials and Methods: In this longitudinal prospective study, 66 HNC patients completed the TH-MDADI and SF-36 at baseline, pre-treatment, and post-treatment at Siriraj Hospital. Psychometric properties were evaluated, including internal consistency (Cronbach’s α), test-retest reliability (intraclass correlation coefficient, ICC), convergent and discriminant validity (correlations with SF-36 domains), and responsiveness (standardized response mean, SRM). Results: The TH-MDADI demonstrated excellent internal consistency (Cronbach’s α = 0.93) and test-retest reliability (ICC = 0.92, 95% CI: 0.88–0.96). Strong correlations with related SF-36 domains (r = 0.64–0.74, p < 0.001) established convergent validity, while weak correlations with unrelated domains confirmed discriminant validity. High responsiveness to change post-treatment was observed, particularly in the Global (SRM = 3.83) and Emotional (SRM = 3.17) subscales. Conclusion: The TH-MDADI demonstrates robust psychometric properties, establishing its value as a reliable tool for assessing dysphagia-related quality of life in Thai HNC patients. This validation represents a significant advancement for Thai cancer care, addressing the historical neglect of patient-reported outcomes. By providing clinicians with a validated assessment instrument, this study promotes a more systematic, patient-centered approach to HNC treatment in Thailand.