P.10.9 A cross sectional validation study of the English version of the NM-Score in patients with neuromuscular diseases

Abstract

The NM-Score is questionnaire based clinical severity score first developed in French to assess functional ability of patients with neuromuscular diseases in 3 domains; D1: standing position and transfers, D2: axial and proximal motor function and D3: distal motor function, thus reflecting the domains tested by the Motor Function Measure (MFM). Previous validation studies have demonstrated its reproductibility (κ = 0.77, 0.69, and 0.64) and its content validity through a Delphi process involving 23 professionals. Its concurrent validity with the Motor Function Measure, the Brooke and Vignos scale was assessed (correlation coefficients from −0.7 to −0.9 with the Motor Function Measure and from 0.63 to 0.86 with Vignos and Brooke scale respectively for D2 and D1) promoting the use of NM-Score as a quick outcome measure in clinical practice to monitor patients and in clinical research for the description and characterization of homogenous groups in regard to motor function. To extend the applicability of the NM-Score to English-speaking patients and professionnals, the NM-Score was forward and backward translated, cross-culturally adapted, and tested for reliability and validity. The study design was cross-sectional and was performed in 60 patients with neuromuscular diseases. For each patient, three different NM-Score scores were administered by a physician, physical therapist and patient or family member to assess informant agreement between patient-reported and clinician-reported clinical severity score. Applicability of NM-Score was studied by response rate and number of missing values. We assessed floor and ceiling effects, test–retest reliability (intraclass correlation) and convergent and discriminant validity (correlations coefficient between NM-Score and MFM, Myometry, Activlim). The English translated and adapted NM-Score can be possibly used in patients affected by neuromuscular diseases to evaluate patients’ motor function in different domains. The NM-Score is questionnaire based clinical severity score first developed in French to assess functional ability of patients with neuromuscular diseases in 3 domains; D1: standing position and transfers, D2: axial and proximal motor function and D3: distal motor function, thus reflecting the domains tested by the Motor Function Measure (MFM). Previous validation studies have demonstrated its reproductibility (κ = 0.77, 0.69, and 0.64) and its content validity through a Delphi process involving 23 professionals. Its concurrent validity with the Motor Function Measure, the Brooke and Vignos scale was assessed (correlation coefficients from −0.7 to −0.9 with the Motor Function Measure and from 0.63 to 0.86 with Vignos and Brooke scale respectively for D2 and D1) promoting the use of NM-Score as a quick outcome measure in clinical practice to monitor patients and in clinical research for the description and characterization of homogenous groups in regard to motor function. To extend the applicability of the NM-Score to English-speaking patients and professionnals, the NM-Score was forward and backward translated, cross-culturally adapted, and tested for reliability and validity. The study design was cross-sectional and was performed in 60 patients with neuromuscular diseases. For each patient, three different NM-Score scores were administered by a physician, physical therapist and patient or family member to assess informant agreement between patient-reported and clinician-reported clinical severity score. Applicability of NM-Score was studied by response rate and number of missing values. We assessed floor and ceiling effects, test–retest reliability (intraclass correlation) and convergent and discriminant validity (correlations coefficient between NM-Score and MFM, Myometry, Activlim). The English translated and adapted NM-Score can be possibly used in patients affected by neuromuscular diseases to evaluate patients’ motor function in different domains.