RÉSUMÉ
Background: Patient-reported outcome measures are largely used in clinical practice and scientific community. Michigan hand questionnaire (MHQ) is widely recognized as a standardized reliable instrument for the assessment of any kind of hand disorders. Aim of the study: translation, cross-cultural adaptation and validation of the Italian version of MHQ. Methods: The study was composed by two phases. Phase 1 consisted in translation and cross-cultural adaptation of MHQ, from original language version (English) into Italian, according to the standard procedure of translation and back translation. The final Italian version of MHQ was tested on 136 Italian patients with hand disorders (Phase 2), in addition to Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, Visual analogue scale (VAS) for pain assessment and grip strength, to psychometric properties of the new version, 55 patients repeated the questionnaire after 7 days for test-retest to assess the reproducibility of the questionnaire. All data were subsequently analyzed (descriptive statistics, multitrait analysis, reliability and construct validity assessment). Results: Phase 1 was performed without major problems, thus the final Italian version was approved for Phase 2. The questionnaire was clear and easily understood (missing data 0-2.9%). Multitrait analysis brought very good results for each outcome measure. High reliability (Cronbach's alpha: 0.91-0.99) and very good reproducibility (Intraclass correlation coefficients: 0.83-0.98) were revealed. High to moderate correlation was found between MHQ and DASH, grip strength and VAS. Conclusions: The Italian version of MHQ has demonstrated to be reliable and valid.