Development of a New Scale of Quality of Life, Specific of Neuro Muscular Diseases and More Specifically of Steinert Disease, by the Rasch Model Methods.

A Quality work was conducted to enable the future construction of a Quality of Life Questionnaire Related to Health (HRQoL) in patients with slowly progressive neuromuscular disease (NMD) as myopathies and muscular dystrophies. The discussion group training is an effective method to perform a thorough investigation of aspects of HRQoL potentially altered by NMD. Patients were recruited in France by 4 reference centers MNMs. All verbal interactions between participants focus groups were recorded. A qualitative analysis of the transcript was performed. The transcript provided 2424 CIF categories. The results helped to identify and quantify aspects of life that are altered by NMDs between patients. A pool of 64 items and a validated questionnaire (the WHOQOLBREF) were thern passed by 159 patients enrolled in eight reference centers MNMs. The investigators constructed a questionnaire called QoLNMD which is composed of two general items and 24 items classified into three areas: (1) \ Impact bodily symptoms, "(2) \ Self-perception" and (3) \ Activity participation. "Each area has good psychometric properties (Cronbach's alpha> 0.77, test-retest ICC> 0.81, H Loevinger> 0.41) and met the assumptions of IRT. the comparison with the WHOQOL-BREF was used to assess similarities and differences with a generic questionnaire. The next step was to validate the QoLNMD reassessing its psychometric properties in a new patient sample and calibrate the IRT measurement system. The purpose of these new part of study was to validate the French version of the QoL-NMD on a confirmatory sample of patients and to calibrate its measurement system. A prospective study in 8 NMD referral centers (France) was conducted. Both the QoL-NMD and a validated generic questionnaire (the WHOQOLBREF) were administered to patients. 156 patients were included for the confirmatory psychometric analysis. All three domains showed adequate psychometric properties and met IRT assumptions. The IRT model calibration was then performed successfully on 315 patients. The French version of the QoL-NMD showed adequate psychometric properties and can be used in rehabilitation services. A conversion table enables easy transformation of sum scores into IRT-calibrated measures. Minimum detectable change tables help interpreting score change.