Carole Vuillerot1, Pascal Rippert2, Virginie Kinet3, Anne Renders3, Minal Jain4, Melissa Waite4, Allan M Glanzman5, Francoise Girardot6, Dalil Hamroun7, Jean Iwaz8, René Ecochard8, Susana Quijano-Roy9, Carole Bérard6, Isabelle Poirot6, Carsten G Bönnemann10. 1. Hospices Civils de Lyon, Hôpital Femme-Mère-Enfant, L'Escale, Service de Médecine Physique et de Réadaptation Pédiatrique, Bron, France; Université de Lyon, Lyon, France; Université Lyon I, Villeurbanne, France; CNRS UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique Santé, Pierre-Bénite, France; National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD. Electronic address: carole.vuillerot@gmail.com. 2. Hospices Civils de Lyon, Pôle Information Médicale, Évaluation, Recherche, Lyon, France. 3. Cliniques Universitaires Saint-Luc, Centre de Référence des maladies neuromusculaires, Université Catholique de Louvain, Brussels, Belgium. 4. Clinical Research Center, National Institutes of Health, Bethesda, MD. 5. Physical Therapy Department, The Children's Hospital of Philadelphia, Philadelphia, PA. 6. Hospices Civils de Lyon, Hôpital Femme-Mère-Enfant, L'Escale, Service de Médecine Physique et de Réadaptation Pédiatrique, Bron, France. 7. Centre Hospitalo-Universitaire de Montpellier, Hôpital Arnaud de Villeneuve, Montpellier, France. 8. Université de Lyon, Lyon, France; Université Lyon I, Villeurbanne, France; CNRS UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique Santé, Pierre-Bénite, France; Hospices Civils de Lyon, Service de Biostatistique, Lyon, France. 9. AP-HP, Hôpitaux Universitaires Paris-Ile-de-France Ouest, Pôle pédiatrique, Centre de Référence Maladies Neuromusculaires (GNMH), Hôpital Raymond Poincaré, Garches, St Quentin, France; Université Versailles Saint-Quentin, St Quentin, France. 10. National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD. Electronic address: carsten.bonnemann@nih.gov.
Abstract
OBJECTIVES: To monitor treatment effects in patients with congenital myopathies and congenital muscular dystrophies, valid outcome measures are necessary. The Motor Function Measure (MFM) was examined for robustness, and changes are proposed for better adequacy. DESIGN: Observational study based on data previously collected from several cohorts. SETTING: Nineteen departments of physical medicine or neuromuscular consultation in France, Belgium, and the United States. PARTICIPANTS: Patients (N=289) aged 5 to 77 years. INTERVENTIONS: None. MAIN OUTCOME MEASURES: A Rasch analysis examined the robustness of the MFM across the disease spectrum. The 3 domains of the scale (standing position and transfers, axial and proximal motor function, and distal motor function) were independently examined with a partial credit model. RESULTS: The original 32-item MFM did not sufficiently fit the Rasch model expectations in either of its domains. Switching from a 4- to a 3-category response scale in 18 items restored response order in 16. Various additional checks suggested the removal of 7 items. The resulting Rasch-scaled Motor Function Measure with 25 items for congenital disorders of the muscle (Rs-MFM25(CDM)) demonstrated a good fit to the Rasch model. Domain 1 was well targeted to the whole severity spectrum-close mean locations for items and persons (0 vs 0.316)-whereas domains 2 and 3 were better targeted to severe cases. The reliability coefficients of the Rs-MFM25(CDM) suggested sufficient ability for each summed score to distinguish between patient groups (0.9, 0.8, and 0.7 for domains 1, 2, and 3, respectively). A sufficient agreement was found between results of the Rasch analysis and physical therapists' opinions. CONCLUSIONS: The Rs-MFM25(CDM) can be considered a clinically relevant linear scale in each of its 3 domains and may be soon reliably used for assessment in congenital disorders of the muscle.
OBJECTIVES: To monitor treatment effects in patients with congenital myopathies and congenital muscular dystrophies, valid outcome measures are necessary. The Motor Function Measure (MFM) was examined for robustness, and changes are proposed for better adequacy. DESIGN: Observational study based on data previously collected from several cohorts. SETTING: Nineteen departments of physical medicine or neuromuscular consultation in France, Belgium, and the United States. PARTICIPANTS: Patients (N=289) aged 5 to 77 years. INTERVENTIONS: None. MAIN OUTCOME MEASURES: A Rasch analysis examined the robustness of the MFM across the disease spectrum. The 3 domains of the scale (standing position and transfers, axial and proximal motor function, and distal motor function) were independently examined with a partial credit model. RESULTS: The original 32-item MFM did not sufficiently fit the Rasch model expectations in either of its domains. Switching from a 4- to a 3-category response scale in 18 items restored response order in 16. Various additional checks suggested the removal of 7 items. The resulting Rasch-scaled Motor Function Measure with 25 items for congenital disorders of the muscle (Rs-MFM25(CDM)) demonstrated a good fit to the Rasch model. Domain 1 was well targeted to the whole severity spectrum-close mean locations for items and persons (0 vs 0.316)-whereas domains 2 and 3 were better targeted to severe cases. The reliability coefficients of the Rs-MFM25(CDM) suggested sufficient ability for each summed score to distinguish between patient groups (0.9, 0.8, and 0.7 for domains 1, 2, and 3, respectively). A sufficient agreement was found between results of the Rasch analysis and physical therapists' opinions. CONCLUSIONS: The Rs-MFM25(CDM) can be considered a clinically relevant linear scale in each of its 3 domains and may be soon reliably used for assessment in congenital disorders of the muscle.
Authors: Stefan J Cano; Anna Mayhew; Allan M Glanzman; Kristin J Krosschell; Kathryn J Swoboda; Marion Main; Birgit F Steffensen; Carole Bérard; Françoise Girardot; Christine A M Payan; Eugenio Mercuri; Elena Mazzone; Bakri Elsheikh; Julaine Florence; Linda S Hynan; Susan T Iannaccone; Leslie L Nelson; Shree Pandya; Michael Rose; Charles Scott; Reza Sadjadi; Mackensie A Yore; Cynthia Joyce; John T Kissel Journal: Muscle Nerve Date: 2013-07-26 Impact factor: 3.217
Authors: Laure Vandervelde; Peter Y K Van den Bergh; Nathalie Goemans; Jean-Louis Thonnard Journal: Neuromuscul Disord Date: 2007-04-11 Impact factor: 4.296
Authors: Anna Mayhew; Stefan Cano; Elaine Scott; Michelle Eagle; Kate Bushby; Francesco Muntoni Journal: Dev Med Child Neurol Date: 2011-03-17 Impact factor: 5.449