Translation, validation and cross-cultural adaptation of the mouth handicap in systemic sclerosis questionnaire into the Turkish language.

AIM: The aim of this study was to translate and adapt the Mouth Handicap in Systemic Sclerosis (MHISS) Questionnaire into the Turkish language and evaluate its validity and reliability in Turkish systemic sclerosis (SSc) patients. METHOD: The MHISS was translated according to Beaton guidelines. Patients being diagnosed with SSc, being between 18-65 years old and receiving no treatment between test-retest assessments were included to study. Test-retest reliability was evaluated, comparing the results of two administrations, with Spearman's correlation. Internal consistency was assessed by Cronbach's α. Validity of the questionnaire was assessed by comparison with mouth opening, total scores of Disabilities of Arm, Shoulder and Hand Questionnaire (DASH) and Health Assessment Questionnaire (HAQ). Construct validity was tested by factor analysis. RESULTS: Forty-five SSc patients were included in the study. The Turkish version of the MHISS (MHISS-T) met set criteria of reliability and validity. Internal consistency (Cronbach's α = 0.863) and test-retest reliability were excellent (r = .88). The correlations between MHISS-T and inter-incisor distance, MHISS-T and HAQ and MHISS-T and DASH were negatively and statistically significant (r = -0.739, P < .001), very good and statistically significant (r = .664, P < .001), good and statistically significant (r = .570, P < .001), respectively. Regarding factor analysis, MHISS-T has three subscales. CONCLUSION: Our results demonstrated that the Turkish version of the MHISS-T has excellent test-retest reliability and very good validity. As a result of this study we determined that MHISS-T is a valid and reliable instrument to measure mouth disabilities in Turkish-speaking SSc patients.