Scott Rooney1, Dr Angus McFadyen2, Dr Leslie Wood3, Dr Fiona Moffat4, Professor Lorna Paul3. 1. School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, Scotland, UK. Electronic address: scott.rooney@gcu.ac.uk. 2. AKM-Stats, Statistical Consultant, Glasgow, Scotland, UK. 3. School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, Scotland, UK. 4. NHS Forth Valley, Scotland, UK.
Abstract
BACKGROUND: Fatigue is a common and debilitating symptom of Multiple Sclerosis (MS); however, it is unknown what constitutes a clinically significant change in fatigue. Establishing the minimally important difference (MID) of fatigue outcome measures can inform the interpretation of changes in fatigue by estimating the level of change that is considered clinically relevant. AIM: Determine the MID for the Fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS) in people with MS. METHODS: This cross-sectional study collected information on self-reported fatigue (FSS and MFIS) and quality of life (EQ-5D and MS Impact Scale 29) through an online survey. Anchor-based methods were used to estimate MID, and ordinal logistic regression models were used to determine the difference in fatigue that would predict a significant effect on quality of life. RESULTS: 365 people with MS (81.9% female, 69.3% relapsing-remitting MS, mean age 46.2 ± 11.6 years, mean time since diagnosis 9.6 ± 8.7 years) responded to the survey. MID estimates for the FSS and MFIS ranged from 0.45-0.88 and 3.86-8.11 respectively, accounting for 6.4-12.6% of maximum FSS score and 4.6-9.7% of maximum MFIS score. CONCLUSIONS: MID estimates derived from this study indicate that a difference of at least 0.45 points on the FSS or 4 points on the MFIS constitutes a clinically significant difference in fatigue. Therefore, these estimates represent a threshold value which can be used to interpret changes in the FSS and MFIS over time or in response to an intervention.
BACKGROUND:Fatigue is a common and debilitating symptom of Multiple Sclerosis (MS); however, it is unknown what constitutes a clinically significant change in fatigue. Establishing the minimally important difference (MID) of fatigue outcome measures can inform the interpretation of changes in fatigue by estimating the level of change that is considered clinically relevant. AIM: Determine the MID for the Fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS) in people with MS. METHODS: This cross-sectional study collected information on self-reported fatigue (FSS and MFIS) and quality of life (EQ-5D and MS Impact Scale 29) through an online survey. Anchor-based methods were used to estimate MID, and ordinal logistic regression models were used to determine the difference in fatigue that would predict a significant effect on quality of life. RESULTS: 365 people with MS (81.9% female, 69.3% relapsing-remitting MS, mean age 46.2 ± 11.6 years, mean time since diagnosis 9.6 ± 8.7 years) responded to the survey. MID estimates for the FSS and MFIS ranged from 0.45-0.88 and 3.86-8.11 respectively, accounting for 6.4-12.6% of maximum FSS score and 4.6-9.7% of maximum MFIS score. CONCLUSIONS: MID estimates derived from this study indicate that a difference of at least 0.45 points on the FSS or 4 points on the MFIS constitutes a clinically significant difference in fatigue. Therefore, these estimates represent a threshold value which can be used to interpret changes in the FSS and MFIS over time or in response to an intervention.
Authors: Farrah J Mateen; Andre C Vogel; Tamara B Kaplan; Gladia C Hotan; Sara J Grundy; Kathryn B Holroyd; Natalie Manalo; Matthew Stauder; Aleksandar Videnovic Journal: J Neurol Date: 2020-04-24 Impact factor: 4.849
Authors: Morten Riemenschneider; Lars G Hvid; Steffen Ringgaard; Mikkel K E Nygaard; Simon F Eskildsen; Thor Petersen; Egon Stenager; Ulrik Dalgas Journal: BMJ Open Date: 2021-01-12 Impact factor: 2.692
Authors: Terry L Wahls; Tyler J Titcomb; Babita Bisht; Patrick Ten Eyck; Linda M Rubenstein; Lucas J Carr; Warren G Darling; Karin F Hoth; John Kamholz; Linda G Snetselaar Journal: Mult Scler J Exp Transl Clin Date: 2021-07-31
Authors: Clara Martínez-Arias; Juan Sobrino-Plata; David Macaya-Sanz; Natalie Marie Aguirre; Carmen Collada; Luis Gil; Juan Antonio Martín; Jesús Rodríguez-Calcerrada Journal: Tree Physiol Date: 2020-06-30 Impact factor: 4.196
Authors: Kristen M Krysko; Antje Bischof; Bardia Nourbakhsh; Roland G Henry; Nisha Revirajan; Michael Manguinao; Khang Nguyen; Amit Akula; Yan Li; Emmanuelle Waubant Journal: Ann Clin Transl Neurol Date: 2021-03-06 Impact factor: 4.511