Validation of the Italian version of the Charcot-Marie-Tooth Health Index (CMT-HI).

BACKGROUND AND AIMS The CMT-HI is a disease-specific patient-reported outcome measure measuring overall disease burden in CMT patients, designed for natural history studies and clinical trials in English-speaking affected individuals. We developed and validated its Italian version (I-CMT-HI). METHODS The questionnaire was translated and culturally adapted from source into Italian by two neurologists experienced in CMT and neuromuscular disorders (NMD). The two translations were reviewed by a panel of seven experts in CMT and NMD. The provisional version was back-translated into English by a professional translator. The definitive Italian version was developed during a consensus teleconference by the panel and a patient representative from ACMT-Rete. A series of clinically and genetically characterized CMT patients completed the final questionnaire; 11 participated in a test-retest reliability assessment of the instrument. RESULTS The I-CMT-HI was administered to 30 CMT patients (13 CMT1A, 8 CMTX1, 2 CMT1B, 2 CMT1E, 2 CMT2I, 1 CMT2A, 1 CMT2N, 1 dHMN), with test-rest in 11:14 females, 16 males, aged (mean ± SD) 48.0 ± 16.4 years (range 18-81), with CMTES = 10.0 ± 4.4 (range 2-18). The I-CMT-HI mean total score was 29.4 ± 21.2 (range 0.1-60.3). The I-CMT-HI showed a high test-retest reliability: ICC = 0.95 (95% CI, 0.84-0.99). No patient had difficulty in completing the questionnaire and none reported any problem with the questions' formulation. The total CMT-HI score was positively correlated with age and CMTES, with higher disease burden with increasing age and disease severity according to the CMTES. INTERPRETATION The I-CMT-HI is now ready for use in clinical studies in the Italian population.