Rasch analysis of clinical outcome measures in spinal muscular atrophy.

INTRODUCTION: Trial design for SMA depends on meaningful rating scales to assess outcomes. In this study Rasch methodology was applied to 9 motor scales in spinal muscular atrophy (SMA). METHODS: Data from all 3 SMA types were provided by research groups for 9 commonly used scales. Rasch methodology assessed the ordering of response option thresholds, tests of fit, spread of item locations, residual correlations, and person separation index. RESULTS: Each scale had good reliability. However, several issues impacting scale validity were identified, including the extent that items defined clinically meaningful constructs and how well each scale measured performance across the SMA spectrum. CONCLUSIONS: The sensitivity and potential utility of each SMA scale as outcome measures for trials could be improved by establishing clear definitions of what is measured, reconsidering items that misfit and items whose response categories have reversed thresholds, and adding new items at the extremes of scale ranges.

Life with home mechanical ventilation for young men with Duchenne muscular dystrophy.

AIM: This paper is a report of a study from a patient perspective of the life experiences with home mechanical ventilation among young men with Duchenne muscular dystrophy. BACKGROUND: People with chronic respiratory failure due to neuromuscular diseases have been offered life-long ventilator support at home for more than a decade. People having this treatment are positive about it and agree on having made the right choice about receiving it. METHOD: Nineteen people with Duchenne muscular dystrophy and invasive home mechanical ventilation were interviewed in 2007. The interviews were tape-recorded, transcribed verbatim and analysed according to a method inspired by Ricoeur's theory of interpretation, which consists of: a naive reading, a structural analysis, and a critical analysis and discussion. FINDINGS: The participants described how the ventilators had saved their lives and were the best thing that had happened to them, but they had had difficulty making the decision of when to start invasive ventilation. Invasive ventilation was preferred to non-invasive ventilation by those who had experienced both. The participants wanted individualized care tailored to their needs in the home setting. Problems were described as being due to both human and technical factors, and sometimes resulted in inadequate ventilation. CONCLUSION: Society needs to discuss if it is a basic human right to be able to breathe, and whether people with Duchenne muscular dystrophy therefore have the right to invasive home mechanical ventilation. Healthcare professionals need to guide ventilator-users in decision-making about when to receive invasive home mechanical ventilation.

Predictors of Health-Related Quality of Life in boys with Duchenne muscular dystrophy from six European countries.

Duchenne muscular dystrophy (DMD) is a progressive, genetically determined neuromuscular disease that affects males and leads to severe physical disability in early teenage years. Over the last decades, patient-reported outcomes such as Health-Related Quality of Life (HRQoL) gained great interest in clinical research. However, little is known about factors affecting HRQoL in boys with DMD. Data from the multi-center CARE-NMD project of boys with DMD from six European countries collected between 2011 and 2012 were analyzed (8-17 years old; n = 321). HRQoL was measured using the KIDSCREEN-10 index, the Pediatric Quality of Life Inventory (PedsQL) and the Neuromuscular Module of the PedsQL (NMM). Linear regression models served to examine influences of socio-demographic, disease- and treatment-specific as well as participation- and environment-related factors on overall and disease-specific HRQoL. Proportions of explained variance varied across models using different outcomes (18-34%). Overall HRQoL according to the KIDSCREEN-10 index was associated with household income, the frequency of attending a clinic with specialized staff, the number of days spent outside home, and the attitude of the local community, but no significant association with age occurred. Overall HRQoL according to the generic PedsQL and disease-specific HRQoL were both positively associated with age and influenced by the country of residence, the disease stage, number of days spent outside home, and the attitude of the local community. Our results may be relevant for clinical practice and planning interventions for this population, but should be confirmed by future research. Further questions for future studies on boys with DMD are proposed.

European Cross-Sectional Survey of Current Care Practices for Duchenne Muscular Dystrophy Reveals Regional and Age-Dependent Differences.

BACKGROUND: Publication of comprehensive clinical care guidelines for Duchenne muscular dystrophy (DMD) in 2010 was a milestone for DMD patient management. Our CARE-NMD survey investigates the neuromuscular, medical, and psychosocial care of DMD patients in Europe, and compares it to the guidelines. METHODS: A cross-sectional survey of 1677 patients contacted via the TREAT-NMD patient registries was conducted using self-report questionnaires in seven European countries. RESULTS: Survey respondents were 861 children and 201 adults. Data describe a European DMD population with mean age of 13.0 years (range 0.8-46.2) of whom 53% had lost ambulation (at 10.3 years of age, median). Corticosteroid medication raised the median age for ambulatory loss from 10.1 years in patients never medicated to 11.4 years in patients who received steroids (p < 0.0001). The majority of patients reported receiving care in line with guidelines, although we identified significant differences between countries and important shortcomings in prevention and treatment. Summarised, 35% of patients aged≥ nine years received no corticosteroid medication, 24% of all patients received no regular physiotherapy, echocardiograms were not performed regularly in 22% of patients, pulmonary function was not regularly assessed in 71% of non-ambulatory patients. Patients with regular follow-up by neuromuscular specialists were more likely to receive care according to guidelines, were better satisfied, and experienced shorter unplanned hospitalization periods.

[Functional assessment for people unable to walk due to spinal muscular atrophy and Duchenne muscular dystrophy. Translation and validation of the Egen Klassifikation 2 scale for the Spanish population]. / Evaluación funcional para personas no ambulantes afectas de atrofia muscular espinal y distrofia muscular de Duchenne. Traducción y validación de la escala Egen Klassifikation 2 para la población española.

INTRODUCTION: The Egen Klassifikation 2 Scale (EK2), expansion of the EK scale, assesses the functional capacity of people with spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) that are in wheelchair phase. This version is more specific for SMA than its EK predecessor. AIM: To examine the validity and reliability of the Spanish version of the scale as a tool for measuring the functional capacity in patients with DMD and SMA who are in wheelchairs. PATIENTS AND METHODS: First, a translation-back-translation into Spanish of the English version of the EK2 was performed; later, we studied the reliability of the translated version. For this, 39 patients, aged between 4 and 60, who were evaluated by two observers, were recruited. To evaluate the intra-observer consistency, two assessments by the same observer were performed, and the inter-observer third assessment was performed by a second observer. RESULTS: The obtained values based on the total score of the scale items (sum EK2) reflect excellent intra- and inter-observer reliability, 0.993 and 0.988 respectively. Also, for each of the items, reliability was excellent except for one item in which it was good. CONCLUSIONS: The Spanish version of the EK2 scale is a valid and reliable instrument for the Spanish population as a tool for measuring the functional capacity in patients with SMA and DMD who are in wheelchairs.

TITLE: Evaluacion funcional para personas no ambulantes afectas de atrofia muscular espinal y distrofia muscular de Duchenne. Traduccion y validacion de la escala Egen Klassifikation 2 para la poblacion española.Introduccion. La escala Egen Klassifikation 2 (EK2), ampliacion de la escala EK, evalua la capacidad funcional de personas con atrofia muscular espinal (AME) y distrofia muscular de Duchenne (DMD) que estan en fase de silla de ruedas. Esta version es mas especifica para la AME que su antecesora. Objetivo. Analizar la validez y fiabilidad de la version española de dicha escala como instrumento de medicion de la capacidad funcional en pacientes afectos de AME y DMD que estan en silla de ruedas. Pacientes y metodos. Primeramente se realizo una traduccion-retrotraduccion al español de la version en ingles de la EK2 y, posteriormente, se estudio la fiabilidad de la version traducida. Para ello, se seleccionaron 39 pacientes, de edades comprendidas entre 4 y 60 años, que fueron valorados por dos observadores. Para evaluar la concordancia intraobservador se realizaron dos evaluaciones por un mismo observador, y para la interobservador, se realizo una tercera evaluacion por un segundo observador. Resultados. Los valores obtenidos referidos a la puntuacion total de los items de la escala (suma EK2) reflejan una fiabilidad intra e interobservador excelente, de 0,993 y 0,988, respectivamente. Asimismo, para cada uno de los items, la fiabilidad fue excelente, a excepcion de un item, en el que fue buena. Conclusiones. La version española de la escala EK2 es un instrumento valido y fiable para la poblacion española como herramienta de medicion de la capacidad funcional en pacientes con AME y DMD que estan en silla de ruedas.

[Translation and validation of the Egen Klassifikation scale for the Spanish population: functional assessment for non-ambulatory individuals with Duchenne's muscular dystrophy and spinal muscular atrophy]. / Traducción y validación de la escala Egen Klassifikation para la población española: evaluación funcional para personas no ambulantes afectas de distrofia muscular de Duchenne y atrofia muscular espinal.

INTRODUCTION: The Egen Klassifikation (EK) scale is a questionnaire that assesses the functional capacity of people with Duchenne muscular dystrophy and spinal muscular atrophy who can't walk and use a wheelchair. AIM: To translate and validate the scale for the Spanish population as a tool for measuring functional capacity in these patients. PATIENTS AND METHODS: We performed first a translation-back translation of EK in the Spanish population and subsequently practiced reliability study of Spanish translated version of the scale. It held three measurements in 30 patients aged 4 to 67 years. Two of these measurements were performed by the same observer, and the third by a second observer to assess intra- and inter-observer agreement. RESULTS: The values refer to the total score of the scale items, EK sum, and reflect a reliability index of 0.995. They also show a higher reliability to 0.86 in each of the items in both intra- and inter-observations observer. CONCLUSIONS: The Spanish version of the EK is a valid and reliable instrument for the Spanish population as a tool for measuring functional capacity in patients with Duchenne muscular dystrophy and spinal muscular atrophy are not ambulatory and use a wheelchair.

TITLE: Traduccion y validacion de la escala Egen Klassifikation para la poblacion espanola: evaluacion funcional para personas no ambulantes afectas de distrofia muscular de Duchenne y atrofia muscular espinal.Introduccion. La escala Egen Klassifikation (EK) es un cuestionario que valora la capacidad funcional de personas con distrofia muscular de Duchenne y atrofia muscular espinal no ambulantes y que estan en silla de ruedas. Objetivo. Traducir y validar la EK para la poblacion espanola, como instrumento de medicion de la capacidad funcional en dichos pacientes. Pacientes y metodos. Se realiza, en primer lugar, una traduccion-retrotraduccion de la EK en la poblacion espanola y, posteriormente, se practica el estudio de fiabilidad de la version traducida al espanol de dicha escala. Se llevan a cabo tres mediciones a 30 pacientes con edades comprendidas entre 4 y 67 anos. Dos de estas mediciones se realizan por el mismo observador, y la tercera, por un segundo observador, para evaluar la concordancia intra e interobservador. Resultados. Los valores obtenidos referidos a la puntuacion total de los items de la escala, suma EK, reflejan un indice de fiabilidad del 0,995. Tambien muestran una fiabilidad superior a 0,86 en cada uno de los items, tanto en las observaciones intra como interobservador. Conclusiones. La version espanola de la EK es un instrumento valido y fiable para la poblacion espanola, como herramienta de medicion de la capacidad funcional en pacientes con distrofia muscular de Duchenne y atrofia muscular espinal no ambulantes y que estan en silla de ruedas.

Living with severe physical impairment, Duchenne's muscular dystrophy and home mechanical ventilation.

AIM: To study life-experiences of people living with Duchenne's muscular dystrophy (DMD), home mechanical ventilation (HMV) and physical impairment. BACKGROUND: Since the introduction of invasive HMV in the late 1980s people with DMD in Denmark live longer and have the experience of adulthood and a high degree of physical dependency. METHOD: Nineteen patients with DMD and invasive HMV were interviewed in 2007. The interviews were recorded, transcribed verbatim and analysed according to a method inspired by Ricoeur's theory of interpretation. FINDINGS: HMV not only extended the participants lifespan, it also gave them the capacity to live an active life. They were totally dependent in everyday living, but in spite of this, they did not see themselves as physically impaired. They realised that there were activities that were physically impossible, but they considered themselves to be just the same person they had always been. This dependency was described as "independent dependency". CONCLUSION: The lived-experience of physical impairment is found to be "independent dependency" in an active life. To solve problems with loneliness, society needs to work with prejudice and misunderstanding and for better physical accessibility to enable full participation.

Physical capacity in non-ambulatory people with Duchenne muscular dystrophy or spinal muscular atrophy: a longitudinal study.

The purpose of this study was to describe functional ability, muscle strength, forced vital capacity, and clinical events in participants with Duchenne muscular dystrophy (DMD) or spinal muscular atrophy (SMA) in the non-ambulatory stages of the diseases. Nineteen non-ambulatory participants with DMD (all males; 13 to 24 years) and 13 with SMA (six males, seven females; 11 to 57 years) were assessed once a year over 5 years. The assessments comprised functional ability measured with the EK scale and upper extremity grade, muscle strength measured with the manual muscle test, and forced vital capacity defined as a percentage of normal values (FVC%). In the DMD group all variables measured deteriorated and there was a direct correlation between them. In the SMA group only muscle strength and FVC% deteriorated and there was no close relation between the variables measured. In the DMD group, 16 participants had cardiorespiratory clinical events leading to death in five cases. In the SMA group only four participants had respiratory clinical events, none leading to death. Although the participants with SMA had been extremely weak and non-ambulatory since early childhood they were older and less exposed to life-threatening events than the participants with DMD.