Journal Article

Assessment of fatigability in patients with spinal muscular atrophy: development and content validity of a set of endurance tests

Stam, Marloes, van der Pol, W. Ludo, Schoenmakers, Marja A. G. C., Takken, Tim, Habets, Laura E., Hulzebos, Erik H.J., Wadman, Renske I., Wijngaarde, Camiel A., Bartels, Bart, de Groot, Janke F.

2019

Overview

Background Fatigability has emerged as an important dimension of physical impairment in patients with Spinal Muscular Atrophy (SMA). At present reliable and valid outcome measures for both mildly and severely affected patients are lacking. Therefore the primary aim of this study is the development of clinical outcome measures for fatigability in patients with SMA across the range of severity. Methods We developed a set of endurance tests using five methodological steps as recommended by the ‘COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). In this iterative process, data from multiple sources were triangulated including a scoping review of scientific literature, input from a scientific and clinical multidisciplinary expert panel and three pilot studies including healthy persons ( N  = 9), paediatric patients with chronic disorders ( N  = 10) and patients with SMA ( N  = 15). Results Fatigability in SMA was operationalised as the decline in physical performance. The following test criteria were established; one method of testing for patients with SMA type 2–4, a set of outcome measures that mimic daily life activities, a submaximal test protocol of repetitive activities over a longer period; external regulation of pace. The scoping review did not generate suitable outcome measures. We therefore adapted the Endurance Shuttle Walk Test for ambulatory patients and developed the Endurance Shuttle Box and Block Test and the - Nine Hole Peg Test for fatigability testing of proximal and distal arm function. Content validity was established through input from experts and patients. Pilot testing showed that the set of endurance tests are comprehensible, feasible and meet all predefined test criteria. Conclusions The development of this comprehensive set of endurance tests is a pivotal step to address fatigability in patients with SMA.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Activities of daily living / Adult / Adults / Atrophy / Care and treatment / Child / Child, Preschool / Endurance / Exercise Test - methods / Exercise Test - standards / Fatigability / Fatigue - diagnosis / Fatigue - etiology / Female / Health / Health aspects / Human performance / Humans / Kinesiology / Male / Measuring instruments / Medicine / Medicine & Public Health / Motor ability / Muscle fatigue / Muscular atrophy / Muscular Atrophy, Spinal - complications / Neurochemistry / Neurology / Neuromuscular diseases / Neuromuscular disorders and peripheral neurology / Neurons / Neurophysiology / Neurosurgery / Occupational therapy / Outcome Assessment (Health Care) / Outcome measure / Patients / Physical Endurance / Pilot Projects / Quality of life / Research Article / Spinal muscular atrophy / Studies / Validity