Development of a patient reported outcome measure for fatigue in motor neurone disease: the Neurological Fatigue Index (NFI-MND)

Health and Quality of Life Outcomes

Research

A Tennant¹  Kevin Talbot²  John Ealing³  Everard W Thornton⁴  John D Mitchell⁵  Pamela J Shaw⁶  Carolyn A Young⁷  Roger J Mills⁷  Chris J Gibbons⁸ 

[1] Academic Department of Rehabilitation Medicine, University of Leeds, Leeds, UK;Department of Clinical Neurology, John Radcliffe Hospital, Oxford, UK;Department of Neurology, Hope Hospital, Stott Lane, Greater Manchester, UK;Department of Psychology, The University of Liverpool, Bedford Street South, Liverpool, UK;Royal Preston Hospital, Sharoe Green Lane, Preston, UK;Sheffield Institute of Translational Neuroscience (SITraN), University of Sheffield, 385A Glossop Road, Sheffield, UK;Walton Centre for Neurology and Neurosurgery, Lower Lane, Liverpool, UK;Walton Centre for Neurology and Neurosurgery, Lower Lane, Liverpool, UK;Department of Psychology, The University of Liverpool, Bedford Street South, Liverpool, UK;

关键词: Differential Item Functioning;    Motor Neurone Disease;    Local Dependency;    Summary Scale;    Misfit Item;   

DOI  :  10.1186/1477-7525-9-101

 received in 2011-04-15, accepted in 2011-11-22,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundThe objective of this research was to develop a disease-specific measure for fatigue in patients with motor neurone disease (MND) by generating data that would fit the Rasch measurement model. Fatigue was defined as reversible motor weakness and whole-body tiredness that was predominantly brought on by muscular exertion and was partially relieved by rest.MethodsQualitative interviews were undertaken to confirm the suitability of a previously identified set of 52 neurological fatigue items as relevant to patients with MND. Patients were recruited from five U.K. MND clinics. Questionnaires were administered during clinic or by post. A sub-sample of patients completed the questionnaire again after 2-4 weeks to assess test-retest validity. Exploratory factor analyses and Rasch analysis were conducted on the item set.ResultsQualitative interviews with ten MND patients confirmed the suitability of 52 previously identified neurological fatigue items as relevant to patients with MND. 298 patients consented to completing the initial questionnaire including this item set, with an additional 78 patients completing the questionnaire a second time after 4-6 weeks. Exploratory Factor Analysis identified five potential subscales that could be conceptualised as representing: 'Energy', 'Reversible muscular weakness' (shortened to 'Weakness'), 'Concentration', 'Effects of heat' and 'Rest'. Of the original five factors, two factors 'Energy' and 'Weakness' met the expectations of the Rasch model. A higher order fatigue summary scale, consisting of items from the 'Energy' and 'Weakness' subscales, was found to fit the Rasch model and have acceptable unidimensionality. The two scales and the higher order summary scale were shown to fulfil model expectations, including assumptions of unidimensionality, local independency and an absence of differential item functioning.ConclusionsThe Neurological Fatigue Index for MND (NFI-MND) is a simple, easy-to-administer fatigue scale. It consists of an 8-item fatigue summary scale in addition to separate scales for measuring fatigue experienced as reversible muscular weakness and fatigue expressed as feelings of low energy and whole body tiredness. The underlying two factor structure supports the patient concept of fatigue derived from qualitative interviews in this population. All three scales were shown to be reliable and capable of interval level measurement.

【 授权许可】

Unknown   
© Gibbons et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.