Determining reliable change on the modified fatigue impact scale (5-item version)

Self-Report Measures of Fatigue for People With Multiple Sclerosis: A Systematic Review

BACKGROUND AND PURPOSE

The symptom of fatigue impairs function in people with multiple sclerosis (MS). Choosing appropriate measures to assess fatigue is challenging. The purpose of this article is to report the findings of a systematic review of patient-reported fatigue measures for people with MS.

METHODS

PubMed, CINAHL, and Embase databases were searched through January 2020 using terms related to fatigue and MS. Studies were included if the sample size was 30 or more or smaller samples if adequately powered, and if information about measurement characteristics (ie, test-retest reliability, content validity, responsiveness, interpretability, or generalizability) of the measure(s) could be extracted. Study quality was appraised with the 2-point COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. Data about measurement characteristics, psychometrics, and clinical utility were extracted and results were synthesized.

RESULTS

Twenty-four articles met inclusion criteria with information about 17 patient-reported fatigue measures. No studies had critical methodologic flaws. Measurement characteristic data were not available for all measures. Clinical utility varied in time to complete and fatigue domains assessed.

DISCUSSION AND CONCLUSIONS

Five measures had data pertaining to all properties of interest. Of these, only the Modified Fatigue Impact Scale (MFIS) and Fatigue Severity Scale (FSS) had excellent reliability, responsiveness data, no notable ceiling/floor effects, and high clinical utility. We recommend the MFIS for comprehensive measurement and the FSS for screening of subjective fatigue in people with MS.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A443 ).

Quality of life in people with multiple sclerosis receiving glatiramer acetate or interferon in Greek clinical practice

Aim: To evaluate glatiramer acetate (GA) or IFN-β effects on quality of life (QoL) in people with relapsing/remitting multiple sclerosis (PwRRMS) in Greece. Methods: A prospective, practice-based study. QoL/function/symptoms were assessed by seven questionnaires/scales. Results: Significant increases in Short Form-36 (SF-36) health survey scores occurred with GA in four of the eight domains and three of the eight domains at 6 and 12 months, respectively, versus baseline. Similar and significant SF-36 score improvements occurred with GA in treatment-naive PwRRMS. SF-36 scores were unaffected in GA-treated, IFN-β treatment-experienced PwRRMS, or with IFN-β versus baseline. Slight improvements in fatigue and sexual satisfaction were evident (6 months). No deteriorations were seen in the other four instruments. Conclusion: The findings show that 12-month treatment with GA, but not IFN-β, improved certain QoL parameters in treatment-naive PwRRMS.

Fear of Relapse Scale: Spanish version and psychometric characteristics in a sample of patients with Relapsing-Remitting multiple sclerosis

INTRODUCTION

Relapses are a hallmark of multiple sclerosis, being a characteristic feature of relapsing-remitting multiple sclerosis (RRMS). The occurrence of a relapse constitutes a source of significant discomfort that impacts all domains of daily life of patients with multiple sclerosis (PwMS). In this study we first explored the psychometric properties of the Spanish version of the Fear of Relapse Scale (FoR) in a sample of patients with RRMS. Besides, we explored the relationship between the Fear of Relapse Scale with fatigue and cognitive perceived deficits in our PwMS sample.

METHODS

An online cross-sectional survey was conducted on 173 MS patients from 12 Spanish-speaking countries (Argentina, Mexico, Uruguay, Dominican Republic, Spain, Cuba, Colombia, Guatemala, Chile, Paraguay, Peru, and El Salvador). Confirmatory factor analysis (CFA) was performed to assess the factor structure of the scale. Multiple linear regression was used to evaluate the effects of health self-perception, fatigue, and perceived cognitive deficits over fear of relapse.

RESULTS

The three-factor model in the CFA yielded a good model fit (χ2/df = 2.25, P < .001, RMSEA = .078, CFI = .91). McDonalds' Omega of the FoR (Spanish version) was .91. There was a statistically significant inverse correlation between FoR and health self-perception, and a positive correlation between FoR, fatigue, and perceived cognitive deficits. Finally, level of fatigue was a predictor of fear of relapse.

CONCLUSIONS

The Spanish version of the Fear of Relapse Scale is a valid and reliable instrument to explore the experience of fear of relapse in patients with RRMS.

Predictors of positive outcomes following resistive inspiratory muscle training in non-ambulatory persons with advanced multiple sclerosis

Background

Inspiratory muscle training (IMT) using a threshold device improves inspiratory muscle strength. What factors influence the IMT outcome has not been examined.

Objective

To identify predictors of the positive outcome following IMT in persons with advanced multiple sclerosis (PwAMS).

Methods

Inclusion criteria were non-ambulatory PwAMS, Expanded Disability Status Scale (EDSS) ≥6.5, age >18 years, no acute medical conditions, current non-smokers, and ability to consent. Participants (n = 38) performed daily inspiratory exercises using a resistive threshold device for 10 weeks. Baseline measurements included age, sex, body mass index, year post multiple sclerosis diagnosis, comorbidities, EDSS, Modified Fatigue Impact Scale-5, and oral Symbol Digit Modality Test. The percentage of completed prescribed exercise trials (Trials%) during the 10-week intervention was calculated. Age- and sex-adjusted predicted values of maximum inspiratory pressure (MIP%pred) and maximum expiratory pressure (MEP%pred) were obtained before and after the 10-week intervention. Backward multivariable regression analyses for the primary outcome (MIP%pred) were conducted.

Results

After controlling for the initial MIP%pred, perceived fatigue at the baseline and Trial% were significant and independent predictors of MIP%pred after IMT.

Conclusion

Less fatigue at the baseline and higher adherence to the prescribed exercise repetitions were positive predictors of the positive outcome following IMT in PwAMS.

A much needed metric: Defining reliable and statistically meaningful change of the oral version Symbol Digit Modalities Test (SDMT)

BACKGROUND

The Symbol Digit Modalities Test (SDMT) has been recommended for use in clinical trials and outcome studies to monitor cognitive change. However, defining what is a meaningful change has been elusive for several years.

OBJECTIVE

The present investigation aimed to develop methods for assessing individual-level statistically significant change on the SDMT - reliable change indices (RCIs) and standardized regression-based (SRB) equations.

METHODS

A total of 219 healthy individuals completed the oral version SDMT at baseline, 6-month and 1-year follow-up.

RESULTS

The SDMT demonstrated high reliability across all time points (r's = 0.83 to 0.86). Reliable change scores of 7, 8, and 10 points for the 6-month intervals represented statistically meaningful change at the 0.70, 0.80, and 0.90 confidence intervals, respectively. Over 1-year, a difference of 8, 10, and 12 was statistically meaningful at the 0.70, 0.80, and 0.90 confidence intervals, respectively. SRB equations are also provided taking into account additional factors found to be predictive of SDMT scores over time.

CONCLUSION

Clinicians frequently denote a decline of 4 points on the SDMT as meaningful. Results in this large normative sample show that higher cut-points are needed to demonstrate statistically significant decline at the individual level. RCIs are provided for 6 month and one year assessment, which is typical in clinical practice and trials. SRB equations are also provided for use when applicable and may provide a more precise assessment of meaningful change.

Characterizing gaze and postural stability deficits in people with multiple sclerosis

BACKGROUND

People with Multiple Sclerosis (PwMS) experience a wide range of symptoms that can alter function and limit activity and community participation. Symptoms including sensory changes, weakness, fatigue and others have been well documented. However, symptoms related to changes in vestibular related function, including gaze and postural stability have not been fully explored. While some recent studies have begun to provide insight into these deficits in PwMS and have explored the use of rehabilitation paradigms for their management, much remains unknown about the full extent of these deficits. Therefore, this study aimed to characterize the presence of gaze and postural stability deficits in measures across the World Health Organization International Classification of Functioning, Disability, and Health (WHO ICF) and to examine how deficits in domains of body structure and function and activity contribute to participation level limitations.

METHODS

Baseline data from 41 PwMS (mean(SD) age = 53.9(11.2), 78% female) enrolled as part of a randomized clinical trial were used in this analysis. Measures of gaze and postural stability from the ICF domains of body structure and function (Vestibular ocular reflex [VOR] gain and postural sway area), activity (computerized dynamic visual acuity [cDVA] and MiniBEST test), and participation (Dizziness handicap inventory [DHI] and Activities Balance Confidence [ABC] scale) along with demographic data were used to characterize the sample. To explore relationships between ICF domains for gaze and postural stability, univariate correlations were performed between measures from each domain using Pearson's correlations. Separate multivariate regression models examined how measures from the body structure and function and activity domains contributed to the variance in the participation level outcomes. Variance explained by the models was quantified using R-squared statistic and contribution of the independent variables were quantified using the beta coefficient (p < 0.05).

RESULTS

Correlation analysis demonstrated significant relationships in the postural stability measures across domains. Specifically, between postural sway area on a firm surface and MiniBEST test score (r = -.48;p < 0.01) and MiniBEST test score and ABC score (r = 0.5;p < 0.01). Significant correlations were also found between the gaze stability measures of horizontal and vertical VOR gain (r = .68;p < 0.001), horizontal VOR gain and dynamic visual acuity (r = .38;p = 0.02), and vertical VOR gain and dynamic visual acuity (r = .54;p < 0.001). Regression models assessing postural stability, found that only the MiniBEST score significantly contributed to the variance in ABC score (p = 0.01) and the full model explained 34% of the variance in ABC score. Regression modeling of gaze stability outcomes did not produce any variable that significantly contributed to the variance in DHI score and the full model explained 18% of the variance in DHI score.

CONCLUSIONS

PwMS in this sample demonstrated deficits in gaze and postural stability across the domains of the WHO ICF compared to past samples of PwMS and healthy cohorts. Correlation between measures in the different domains were present, but no strong relationship between measures of body structure and function, activity and participation level outcomes were observed. This lack of relationship across the domains is likely contributed to the relatively small sample size, the high level of variability observed in the outcomes, and the diverse presentation often seen in PwMS.

Postural stability is a valid and meaningful disability metric in progressive MS with potential for use in neuroprotective therapy trials

BACKGROUND

Balance impairment is observed in up to 70% of people with MS (pwMS) and worsens with disease progression. Posturography using a force platform is the current gold standard in the measurement of balance. However, posturography has not been adequately studied or widely accepted for use as a disability outcome measure for pwMS. Importantly, the recent emergence of both successful and failed neuroprotective therapy trials in progressive MS has emphasised the need for new disability outcome measures for people with progressive MS. The main objectives of this study were to evaluate the clinical validity, reliability and feasibility of posturography as a disability metric in progressive MS.

METHODS

This was a prospective cross-sectional study. We recruited 73 people with progressive MS (age 18-65 years, EDSS 3.5-6.0). Participants stood in the centre of a force platform, feet comfortably apart, under various conditions: (i) eyes open (EO), (ii) eyes closed (EC) - a single task, each lasting ninety seconds; and simultaneous EO with a cognitive test: (iii) N-Back, a three-minute test whereby participants were instructed to click the mouse when two identical letters were displayed consecutively on a screen, (iv) Sustained Attention Response Task, a five-minute test whereby participants were instructed to click the mouse for every number "1″ to "9″ except "3″ - i.e., dual-tasks. Additionally, we performed a battery of validated physical and cognitive outcome measures. Posturographic data was processed using Matlab. Statistical analysis was performed using SPSS version 26. We used multiple linear regression modelling to determine whether significant univariate correlations between posturography and clinical metrics were independent of covariates that may influence the associations seen. A two-tailed significance level of 0.05 was used.

RESULTS

Of 73 participants, mean age 52.4 (8.5) years, mean MS disease duration 13.8 (10.3) years, median EDSS 5.0 (IQR 4.0-6.0), 44 (60.4%) were female. EO-Path-Length independently predicted upper extremity function (9-Hole-Peg-Test) with a larger effect size (adjusted R²=20.0%, p = 0.001) than that for walking measures (Timed 25-Foot Walk, adjusted R²=1.6%, p = 0.01; Two-Minute Walk Test, adjusted R²=7.2%, p = 0.002), while controlling for age, disease duration, height, weight, and sex. The addition of EO-Mediolateral-Displacement to the MS Functional Composite (MSFC) created a four-component z-score that increased the variance explained for quality of life (QOL) by 62.1%. Postural stability was significantly lower with mediolateral vs anteroposterior direction of sway, removal of vision, increased body weight, male sex, and fampridine use. Postural stability improved during dual-tasks compared to EO single task. Posturography detected significant worsening of balance over a single prolonged stance.

CONCLUSION

Postural stability independently predicted a wide range of clinical metrics including upper extremity function, walking ability, cognition and QOL, therefore establishing construct and concurrent validity as a disability outcome measure for people with progressive MS. Additionally, posturography is a quantitative, non-invasive, quick-and-easy-to-administer, and highly sensitive device, demonstrating its high feasibility for use as a time- and resource-efficient disability metric in neuroprotective therapy trials for progressive MS.

A quick assessment of reliable change in fatigue: Reliable change indices of the modified fatigue impact scale - 5 item (MFIS-5)

BACKGROUND

Reliably monitoring changes in fatigue is an ongoing concern.

OBJECTIVE

Evaluate reliable change using the Modified Fatigue Impact Scale 5-item version (MFIS-5) in people with MS (PwMS).

METHODS

The MFIS-5 was administered at three time points in 157 PwMS. Test-retest reliability and reliable change scores were calculated at the 0.70, 0.80, 0.90, and 0.95 confidence intervals.

RESULTS

Difference scores of 3, 4, 5, and 6 represent statistically meaningful change at the 0.70, 0.80, 0.90, and 0.95 confidence intervals, respectively.

CONCLUSION

Cut points derived from this study and prior work can help reliably assess changes in fatigue over time.

Assessing fatigue in multiple sclerosis: Psychometric properties of the five-item Modified Fatigue Impact Scale (MFIS-5)

Fatigue in multiple sclerosis is a key symptom associated with work-related problems and poor quality of life outcomes. The five-item Modified Fatigue Impact Scale is a brief self-assessment tool for measuring the impact of fatigue on cognitive, physical and psychosocial function. A non-interventional, cross-sectional study was conducted to assess dimensionality and item characteristics of the five-item Modified Fatigue Impact Scale in multiple sclerosis. A total of 302 subjects were studied. Mokken analysis found the five-item Modified Fatigue Impact Scale is a strong one-dimensional scale (overall scalability index H = 0.67) with high reliability (Cronbach's alpha = 0.90). The confirmatory factor analysis model confirmed the one-dimensional structure (comparative fit index = 1.0, root-mean-square error of approximation = 0.035). Samejima's model fitted well as an unconstrained model with different item difficulties. The five-item Modified Fatigue Impact Scale shows appropriate psychometric characteristics and may constitute a valuable and easy-to-implement addition to measure the impact of fatigue in clinical practice.