Validity of the Thai Version of Disability of the Arm, Shoulder and Hand Questionnaire (KKU-DASH) in Patients with Brachial Plexus Injury

Objective: To assess the reliability and validity of the Thai version of the Disability of the Arm, Shoulder, and Hand (KKUDASH) questionnaire in patients with brachial plexus injuries. Material and Method: The Thai KKU-DASH version was performed based on translation/back translation methodology. Thirty-four Thai-speaking patients with brachial plexus injuries completed the KKU-DASH and the 36-item short-form health survey (SF-36) questionnaires preoperatively and then were reassessed for test-retest reliability two months later. Reliability was investigated for reproducibility and internal consistency. The validity was evaluated by using component analysis and the correlations coefficients between the KKU-DASH and the SF-36. Results: The internal consistency of the degree of difficulty, severity of pain, and social activity domains of the KKU-DASH was good to excellent (Cronbach’s alpha 1.00, 0.75, and 1.00). The intraclass correlation coefficient (ICCs) for the test-retest reliability was 0.52. For the degree of difficulty, severity of pain, social activity, and psychological effect on self-image, the ICC were 0.5, 0.45, 0.57, and 0.53 respectively. The convergent validity between the KKU-DASH and SF-36 was -0.76. The convergent validity of each domain between both instruments ranged from 0.46 to 0.69 and the strongest correlation was observed in the social activity domain. Conclusion: According to the reliability and validity testing, the KKU-DASH questionnaire is suitable for Thai-speaking patients with brachial plexus injuries. Keywords: Thai KKU-DASH, Brachial plexus injuries