Alina Ionela Palimaru1, William E Cunningham2, Marcus Dillistone3, Arturo Vargas-Bustamante4, Honghu Liu5, Ron D Hays2. 1. Department of Health Policy and Management, Fielding School of Public Health, The University of California, Los Angeles (UCLA), Los Angeles, California, United States. Electronic address: alinapalimaru@ucla.edu. 2. Department of Health Policy and Management, Fielding School of Public Health, The University of California, Los Angeles (UCLA), Los Angeles, California, United States; Division of General Internal Medicine and Health Services Research, Department of Medicine, Geffen School of Medicine, UCLA, Los Angeles, California, United States. 3. Royal Society of Medicine, Marylebone, London, United Kingdom. 4. Department of Health Policy and Management, Fielding School of Public Health, The University of California, Los Angeles (UCLA), Los Angeles, California, United States. 5. Division of General Internal Medicine and Health Services Research, Department of Medicine, Geffen School of Medicine, UCLA, Los Angeles, California, United States; Division of Public Health and Community Dentistry, School of Dentistry, UCLA, Los Angeles, California, United States; Department of Biostatistics, Fielding School of Public Health, UCLA, Los Angeles, California, United States.
Abstract
OBJECTIVE: To develop and evaluate psychometrically a self-reported instrument assessing physical fatigability (PF) and mental fatigability (MF) in adults with spinal cord injury (SCI). DESIGN: Cross-sectional. SETTING: Peer-support groups at rehabilitation centers, online support groups. PARTICIPANTS: Adults with SCI (N=464) in the United States. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The dimensional structure was assessed by confirmatory factor analysis. The relationship between item responses and fatigability was measured with item response theory (graded response model). Reliability was measured with test information functions. Differential item functioning was evaluated with Wald chi-square tests and the weighted area between the curves. Construct validity was assessed using the known groups method. RESULTS: An 82-item pool was developed from prior qualitative research and consultations with rehabilitation experts. A non-probability sample (N=464) was used to evaluate the psychometric properties of the PF and MF scales. The item pool was reduced to 75 based on factor loadings and R2. Both scales are primarily unidimensional, despite moderate multidimensionality. There is good discrimination overall: 18 PF items and 26 MF items have high or very high discrimination power (slopes > 1.35). The measurement precision in the theta range -2.0 to 2.5 is the equivalent of 0.94 reliability for PF and 0.91 for MF. For both measures, F statistics P values were significant at P<.01, and means were higher for those with paraplegia vs quadriplegia, and for those with incomplete paraplegia. CONCLUSIONS: The Fatigability Index is the first instrument designed to assess physical and mental fatigability in adults with SCI. The index highlights causes of fatigue and areas requiring immediate intervention. Development of short-forms and further research on representative samples are necessary.
OBJECTIVE: To develop and evaluate psychometrically a self-reported instrument assessing physical fatigability (PF) and mental fatigability (MF) in adults with spinal cord injury (SCI). DESIGN: Cross-sectional. SETTING: Peer-support groups at rehabilitation centers, online support groups. PARTICIPANTS: Adults with SCI (N=464) in the United States. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The dimensional structure was assessed by confirmatory factor analysis. The relationship between item responses and fatigability was measured with item response theory (graded response model). Reliability was measured with test information functions. Differential item functioning was evaluated with Wald chi-square tests and the weighted area between the curves. Construct validity was assessed using the known groups method. RESULTS: An 82-item pool was developed from prior qualitative research and consultations with rehabilitation experts. A non-probability sample (N=464) was used to evaluate the psychometric properties of the PF and MF scales. The item pool was reduced to 75 based on factor loadings and R2. Both scales are primarily unidimensional, despite moderate multidimensionality. There is good discrimination overall: 18 PF items and 26 MF items have high or very high discrimination power (slopes > 1.35). The measurement precision in the theta range -2.0 to 2.5 is the equivalent of 0.94 reliability for PF and 0.91 for MF. For both measures, F statistics P values were significant at P<.01, and means were higher for those with paraplegia vs quadriplegia, and for those with incomplete paraplegia. CONCLUSIONS: The Fatigability Index is the first instrument designed to assess physical and mental fatigability in adults with SCI. The index highlights causes of fatigue and areas requiring immediate intervention. Development of short-forms and further research on representative samples are necessary.
Authors: Alina Palimaru; William E Cunningham; Marcus Dillistone; Arturo Vargas-Bustamante; Honghu Liu; Ron D Hays Journal: Qual Life Res Date: 2017-07-15 Impact factor: 4.147
Authors: Catherine A Richardson; Nancy W Glynn; Luigi G Ferrucci; Dawn C Mackey Journal: J Gerontol A Biol Sci Med Sci Date: 2014-09-04 Impact factor: 6.053
Authors: Alan M Jette; Mary D Slavin; Pengsheng Ni; Pamela A Kisala; David S Tulsky; Allen W Heinemann; Susie Charlifue; Denise G Tate; Denise Fyffe; Leslie Morse; Ralph Marino; Ian Smith; Steve Williams Journal: J Spinal Cord Med Date: 2015-05 Impact factor: 1.985
Authors: David Cella; Hilary Wilson; Huda Shalhoub; Dennis A Revicki; Joseph C Cappelleri; Andrew G Bushmakin; Elizabeth Kudlacz; Ming-Ann Hsu Journal: J Patient Rep Outcomes Date: 2019-05-20