Real-Time Assessment of Fatigue in Patients With Multiple Sclerosis: How Does It Relate to Commonly Used Self-Report Fatigue Questionnaires?

Determining minimal clinically important differences in ecological momentary assessment measures of fatigue in people with multiple sclerosis

PURPOSE

Fatigue is a common debilitating symptom of multiple sclerosis (MS). Ecological momentary assessment (EMA) provides a more reliable and sensitive assessment of fatigue outcomes relative to traditional recall surveys; however, the minimal clinically important difference (MCID) for EMA fatigue outcomes has not been established.

METHODS

MCIDs for EMA fatigue intensity and fatigue interference (0-10 numerical rating scale) that were assessed as outcomes in a pragmatic randomized clinical trial of three fatigue interventions were determined using two statistical approaches. The Patient Global Impression of Change (PGIC) and the Modified Fatigue Impact Scale (MFIS) were used within the anchor-based approach, and standard deviations (SD) and standard error of measurements (SEM) were examined within the distribution-based approach.

RESULTS

Pre- and post-treatment EMA data from 336 individuals with MS (76.2% female, 71.1% relapsing-remitting MS, mean age 48.8 (± 11.7) years, mean duration of MS 12.2 (± 9.8) years) were included in the analysis. Percent complete EMA data (4 EMAs/day) for 7 days were comparable pre- and post-treatment for fatigue intensity and for fatigue interference. Using the PGIC and MFIS anchors, change in EMA scores averaged 0.94 and 1.04 for fatigue intensity and 0.62 and 1.04 for fatigue interference, respectively. The SD and SEM for EMA fatigue intensity were 0.75 and 1.19 and for EMA fatigue interference were 0.83 and 1.30, respectively.

CONCLUSION

Combining two approaches, our study contributes foundational information regarding meaningful change on EMA measures of fatigue, enabling effective use of EMA to assess fatigue treatment outcomes in a person-centered manner.

Fatigue in multiple sclerosis: can we measure it and can we treat it?

Fatigue is a common and debilitating symptom in multiple sclerosis (MS). However, after over 100 years of inquiry its definition, measurement and understanding remains elusive. This paper describes the challenges clinicians and researchers face when assessing and treating MS patients, as well as our understanding of neural mechanisms involved in fatigue. Challenges for the future are discussed.

The Relationship between Diurnal Measures of Tonic Alertness and Self-Reported Fatigue in Persons with Multiple Sclerosis-A Retrospective Data Analysis

OBJECTIVE

Fatigue in multiple sclerosis (MS) is common, burdensome, and usually assessed by self-report measures. This retrospective data analysis of the twice-daily Alertness test (Test battery of Attentional Performance) examined the extent to which this assessment procedure is associated with MS-related fatigue.

METHOD

Two-hundred and thirteen German inpatients (136 women) aged 18-69 years with predominantly relapsing MS (72.8%) were included. Based on reaction time (RT) differences between morning tonic alertness (8:30-11:00 a.m.) and afternoon tonic alertness (3:00-4:30 p.m.), patients were divided into an "improver," "maintainer," or "decliner" group. Multinomial logistic regression (MLR) was calculated to predict the likelihood of belonging to one of these performance groups, taking into account cognitive fatigue (Fatigue Scale of Motor and Cognition, FSMCcog), disease severity (Expanded Disability Status Scale, EDSS), depression (Center for Epidemiologic Studies Depression Scale, CES-D), gender, and tonic alertness (a.m.).

RESULTS

The final MLR model (R2 = .30) included tonic alertness (a.m.) (<.001), FSMCcog (.008), EDSS (.038), CES-D (.161), and gender (.057). Using this model, correct assignment to alertness performance groups was 56.8%. Tonic alertness (p.m.) demonstrated the greatest potential for differentiation among the three performance groups (<.001).

CONCLUSIONS

These results show a relationship between subjective fatigue and tonic alertness. However, other variables also contribute to this association, suggesting that the RT differences between twice-daily measures of tonic alertness is not related to increased subjective fatigue in a substantial number of pwMS, which diminishes the diagnostic value. Further studies including relevant variables such as sleepiness are urgently needed.

Daily patterns of fatigue after subarachnoid haemorrhage: an ecological momentary assessment study

OBJECTIVE

To examine the daily course of, and factors associated with, momentary fatigue after subarachnoid haemorrhage, and to explore subgroups of patients with distinct diurnal patterns of fatigue.

DESIGN

Observational study using ecological momentary assessment.

SUBJECTS

A total of 41 participants with subarachnoid haemorrhage.

METHODS

Patients with fatigue were included within one year post-onset. Momentary fatigue (scale 1-7) was assessed with repeated measurements (10-11 times/day) during 7 consecutive days. Multilevel-mixed-model analyses and latent-class trajectory modelling were conducted.

RESULTS

Mean (standard deviation; SD) age of the group was 53.9 (13.0) years, 56% female, and mean (SD) time post-subarachnoid haemorrhage onset was 9.3 (3.2) months. Mean (SD) momentary fatigue over all days was 3.22 (1.47). Fatigue increased significantly (p < 0.001) over the day, and experiencing more burden of fatigue and day type (working day vs weekend day) were significantly (p < 0.05) associated with higher momentary fatigue. Three subgroups could be distinguished based on diurnal patterns of fatigue. The largest group (n = 17, 41.5%) showed an increasing daily pattern of fatigue.

CONCLUSION

Momentary fatigue in patients with subarachnoid haemorrhage increases over the day, and diurnal patterns of fatigue differ between  participants. In addition to conventional measures, momentary measures of fatigue might provide valuable information for physicians to optimize personalized management of fatigue after subarachnoid haemorrhage.

Real-time daily fatigue, sleep, physical activity, and health-related fitness in adults with cerebral palsy

AIM

To explore whether subgroups of adults with cerebral palsy (CP) with different fatigue diurnal profiles can be discerned, and to explore whether sleep, physical activity, or health-related fitness are associated with these profiles.

METHOD

Thirty-two adults (median age 29 years 8 months; range 20-54 years; 11 males, 21 females) with spastic CP (Gross Motor Function Classification System levels I-III) with physical activity-related fatigue complaints participated. Real-time fatigue and physical activity were assessed for 7 consecutive days by short message service text four times during the day and by wearing an accelerometer respectively. Sleep was assessed by the Pittsburgh Sleep Quality Index, and fitness by assessing body composition and aerobic capacity. Latent class growth modelling was used to classify subgroups according to their diurnal profiles of real-time fatigue. Univariable multinomial logistic regression analysis explored whether participant characteristics, sleep, physical activity, or health-related fitness were associated with diurnal profiles.

RESULTS

Three distinct fatigue diurnal profiles were identified: stable low (n = 10), increasing (n = 14), and stable high (n = 8). Only aerobic capacity was associated with fatigue profiles (odds ratio 1.15, 95% confidence interval 1.00-1.34; p = 0.05).

INTERPRETATION

Fatigue in adults with CP may be low or high stable or may increase during the day. These findings indicate the relevance of assessing fatigue variability.

WHAT THIS PAPER ADDS

We found three patterns of daily fatigue in adults with cerebral palsy (CP). Only aerobic capacity was associated with fatigue profiles in adults with CP. Moment-to-moment variations in fatigue can help with personalized fatigue management.

Real-time associations among MS symptoms and cognitive dysfunction using ecological momentary assessment

Introduction

Multiple sclerosis (MS) is characterized by a wide range of disabling symptoms, including cognitive dysfunction, fatigue, depression, anxiety, pain, and sleep difficulties. The current study aimed to examine real-time associations between non-cognitive and cognitive symptoms (latter measured both objectively and subjectively in real-time) using smartphone-administered ecological momentary assessment (EMA).

Methods

Forty-five persons with MS completed EMA four times per day for 3 weeks. For each EMA, participants completed mobile versions of the Trail-Making Test part B (mTMT-B) and a finger tapping task, as well as surveys about symptom severity. Multilevel models were conducted to account for within-person and within-day clustering.

Results

A total of 3,174 EMA sessions were collected; compliance rate was 84%. There was significant intra-day variability in mTMT-B performance (p < 0.001) and levels of self-reported fatigue (p < 0.001). When participants reported depressive symptoms that were worse than their usual levels, they also performed worse on the mTMT-B (p < 0.001), independent of upper extremity motor functioning. Other self-reported non-cognitive symptoms were not associated with real-time performance on the mTMT-B [p > 0.009 (Bonferroni-corrected)]. In contrast, when self-reported fatigue (p < 0.001), depression (p < 0.001), anxiety (p < 0.001), and pain (p < 0.001) were worse than the individual's typical levels, they also reported more severe cognitive dysfunction at the same time. Further, there was a statistical trend that self-reported cognitive dysfunction (not mTMT-B performance) predicted one's self-reported sense of accomplishment in real-time.

Discussion

The current study was the first to identify divergent factors that influence subjectively and objectively measured cognitive functioning in real time among persons with MS. Notably, it is when symptom severity was worse than the individual's usual levels (and not absolute levels) that led to cognitive fluctuations, which supports the use of EMA in MS symptom monitoring.

The Role of Remote Monitoring in Evaluating Fatigue in Multiple Sclerosis: A Review

Fatigue is one of the most common multiple sclerosis (MS) symptoms. Despite this, monitoring and measuring fatigue (subjective lack of energy)- and fatigability (objectively measurable and quantifiable performance decline)- in people with MS have remained challenging. Traditionally, administration of self-report questionnaires during in-person visits has been used to measure fatigue. However, remote measurement and monitoring of fatigue and fatigability have become feasible in the past decade. Traditional questionnaires can be administered through the web in any setting. The ubiquitous availability of smartphones allows for momentary and frequent measurement of MS fatigue in the ecological home-setting. This approach reduces the recall bias inherent in many traditional questionnaires and demonstrates the fluctuation of fatigue that cannot be captured by standard measures. Wearable devices can assess patients' fatigability and activity levels, often influenced by the severity of subjective fatigue. Remote monitoring of fatigue, fatigability, and activity in real-world situations can facilitate quantifying symptom-severity in clinical and research settings. Combining remote measures of fatigue as well as objective fatigability in a single construct, composite score, may provide a more comprehensive outcome. The more granular data obtained through remote monitoring techniques may also help with the development of interventions aimed at improving fatigue and lowering the burden of this disabling symptom.

Distinguishing between Fatigue and Fatigability in Multiple Sclerosis

Fatigue is one of the most common debilitating symptoms reported by persons with multiple sclerosis (MS). It reflects feelings of tiredness, lack of energy, low motivation, and difficulty in concentrating. It can be measured at a specific instant in time as a perception that arises from interoceptive networks involved in the regulation of homeostasis. Such ratings indicate the state level of fatigue and likely reflect an inability to correct deviations from a balanced homeostatic state. In contrast, the trait level of fatigue is quantified in terms of work capacity (fatigability), which can be either estimated (perceived fatigability) or measured (objective fatigability). Clinically, fatigue is most often quantified with questionnaires that require respondents to estimate their past capacity to perform several cognitive, physical, and psychosocial tasks. These retrospective estimates provide a measure of perceived fatigability. In contrast, the change in an outcome variable during the actual performance of a task provides an objective measure of fatigability. Perceived and objective fatigability do not assess the same underlying construct. Persons with MS who report elevated trait levels of fatigue exhibit deficits in interoceptive networks (insula and dorsal anterior cingulate cortex), including increased functional connectivity during challenging tasks. The state and trait levels of fatigue reported by an individual can be modulated by reward and pain pathways. Understanding the distinction between fatigue and fatigability is critical for the development of effective strategies to reduce the burden of the symptom for individuals with MS.

Assessment of Activity Pacing in Relation to Physical Activity and Health-Related Quality of Life in Adults with Multiple Sclerosis: A Foundation for Further Intervention Development

BACKGROUND

Activity pacing is a behavioral strategy for coping with fatigue, optimizing physical activity (PA) levels, and achieving a paced approach to lifestyle and sustainable self-regulated exercise practice to optimize health and well-being. Yet little is known about how activity pacing affects PA and health-related quality of life (HRQOL) while controlling for fatigue and demographic characteristics over time in adults with multiple sclerosis (MS). This study examined the natural use of activity pacing and how it is associated with PA and HRQOL over time in adults with MS.

METHODS

Sixty-eight adults with MS (mean ± SD age, 45.2 ± 10.9 years) completed questionnaires on their activity pacing, fatigue, PA, and HRQOL 14, 33, and 52 weeks after rehabilitation. Associations between the variables were examined using multilevel models.

RESULTS

No associations were found between activity pacing and PA (β = -0.01, P = .89) or between activity pacing and HRQOL (β = -0.15, P = .09).

CONCLUSIONS

This study provides an initial understanding of how activity pacing relates to PA and HRQOL in people with MS over time and indicates that there is no clear strategy among adults with MS that is successful in improving PA and HRQOL in the short or long term. Persons with MS may benefit from goal-directed activity pacing interventions to improve longitudinal engagement in PA, and the present study provides a foundation for further intervention development.

How to measure fluctuating impairments in people with MS: development of an ambulatory assessment version of the EQ-5D-5L in an exploratory study

Background

Health fluctuations even within a single day are typical in multiple sclerosis (MS), but are not captured by widely used questionnaires like the EQ-5D-5L. This exploratory study aimed to develop an ambulatory assessment (AA) version of the EQ-5D-5L (EQ-5D-AA) where patients rate their health on mobile phones multiple times per day over several days, and to assess its feasibility and face validity.

Methods

An initial EQ-5D-AA version was based on two patient focus groups. It was then tested and continuously developed in an iterative process: patients completed it over several days, followed by debriefing interviews. Findings were used to refine the EQ-5D-AA, with the resulting version being tested by the subsequent wave of patients until participants declared no need for changes anymore. Before and after the AA period, participants completed the standard paper-based EQ-5D-5L asking about ‘today’.

Results

Focus group participants reported that their impairments often fluctuated between and within days. They regarded an AA with three assessments per day over seven days most appropriate; assessment should be retrospective to the previous assessment, but not all items should be assessed at each time point. Four waves of AA testing were conducted. Thirteen out of the 17 participants preferred the AA over standard assessment as they regarded it more informative, but not too burdensome.

Conclusion

The newly developed one-week AA of the EQ-5D-5L captures within-day and day-to-day health fluctuations in people with MS. From the patients’ perspective, it is a feasible and face valid way to provide important information beyond what is captured by the standard EQ-5D-5L.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11136-021-02802-8.

Early neuropsychological markers of cognitive involvement in multiple sclerosis

BACKGROUND

Cognitive impairment due to multiple sclerosis (MS) is common and often limits occupational functioning, contributes to disability, and reduces quality of life. Early detection of cognitive involvement in MS is critical for treatment planning and intervention, and frequent, regular cognitive monitoring may provide insight into subtle changes in disease progression.

OBJECTIVE

To compare the sensitivity and specificity of clinical, computer-based and experimental measures to early cognitive involvement in MS.

METHODS

Cognitive functioning was compared in MS participants early in the disease course to matched healthy controls using conventional, computer-based and functional assessments: the Brief International Cognitive Assessment in MS (BICAMS); the computer-based Cogstate Brief Battery (CBB); the Attention Network Test-Interaction (ANT-I), including intra-individual variability; and the Test of Everyday Cognitive Ability (TECA), a functional measure of instrumental activities of daily living.

RESULTS

MS participants (n = 25, mean disease duration= 5.82 ± 3.65 years) and demographically matched healthy controls (n = 29) completed the cognitive assessments. The Cogstate measure of choice reaction time (AUC = 0.73, p = .004), intra-individual variability on the ANT-I (AUC = 0.79, p = .001), and TECA (AUC = 0.78, p = .001) scores were the most sensitive and specific markers of cognitive involvement in MS.

CONCLUSIONS

Brief, repeatable, computer-based measures of reaction time and variability detect early MS associated cognitive involvement.

Real-world keystroke dynamics are a potentially valid biomarker for clinical disability in multiple sclerosis

Background:

Clinical measures in multiple sclerosis (MS) face limitations that may be overcome by utilising smartphone keyboard interactions acquired continuously and remotely during regular typing.

Objective:

The aim of this study was to determine the reliability and validity of keystroke dynamics to assess clinical aspects of MS.

Methods:

In total, 102 MS patients and 24 controls were included in this observational study. Keyboard interactions were obtained with the Neurokeys keyboard app. Eight timing-related keystroke features were assessed for reliability with intraclass correlation coefficients (ICCs); construct validity by analysing group differences (in fatigue, gadolinium-enhancing lesions on magnetic resonance imaging (MRI), and patients vs controls); and concurrent validity by correlating with disability measures.

Results:

Reliability was moderate in two (ICC = 0.601 and 0.742) and good to excellent in the remaining six features (ICC = 0.760–0.965). Patients had significantly higher keystroke latencies than controls. Latency between key presses correlated the highest with Expanded Disability Status Scale (r = 0.407) and latency between key releases with Nine-Hole Peg Test and Symbol Digit Modalities Test (ρ = 0.503 and r = −0.553, respectively), ps < 0.001.

Conclusion:

Keystroke dynamics were reliable, distinguished patients and controls, and were associated with clinical disability measures. Consequently, keystroke dynamics are a promising valid surrogate marker for clinical disability in MS.

Associations between Activity Pacing, Fatigue, and Physical Activity in Adults with Multiple Sclerosis: A Cross Sectional Study

Fatigue is common in people with multiple sclerosis (MS). Activity pacing is a behavioral way to cope with fatigue and limited energy resources. However, little is known about how people with MS naturally pace activities to manage their fatigue and optimize daily activities. This study explored how activity pacing relates to fatigue and physical activity in people with MS. Participants were 80 individuals (60 females, 20 males) with a diagnosis of MS. The participants filled in questionnaires on their activity pacing, fatigue, physical activity, and health-related quality of life, 3-6 weeks before discharge from rehabilitation. The relationships between the variables were examined using hierarchical regression. After controlling for demographics, health-related quality of life, and perceived risk of overactivity, no associations were found between activity pacing and fatigue (β = 0.20; t = 1.43, p = 0.16) or between activity pacing and physical activity (β = -0.24; t = -1.61, p = 0.12). The lack of significant associations between activity pacing and fatigue or physical activity suggests that without interventions, there appears to be no clear strategy amongst people with MS to manage fatigue and improve physical activity. People with MS may benefit from interventions to manage fatigue and optimize engagement in physical activity.

Is Symptomatic Fatigue Associated With Physical Activity and Sedentary Behaviors Among Persons With Multiple Sclerosis?

Background. Fatigue is a debilitating symptom in multiple sclerosis (MS) that may be associated with reduced physical activity and increased sedentary behavior. Objective. This study examined the associations among fatigue and device-measured physical activity and sedentary behavior in people with MS. Methods. The participants (n = 252) completed the Patient Determined Disease Steps (PDDS) and Fatigue Severity Scale (FSS) and wore a waist-mounted accelerometer for 7 days. Participants were divided into 2 groups based on fatigue severity as measured by the FSS scale. We compared percentage of wear time spent in sedentary, light physical activity (LPA), and moderate to vigorous physical activity (MVPA) between the 2 groups. Results. Persons in the fatigued group (FSS score ≥ 4) spent a greater percentage of time in sedentary behavior (P = .004) and a lower percentage of time in LPA (P = .035). Persons in the fatigued group further spent a lower percentage of time in nontransformed MVPA (P < .001) and square-root-transformed MVPA (P < .001) than persons in the nonfatigued group. When controlling for PDDS scores and years of education, there were no longer significant differences between groups in sedentary behavior, LPA, or transformed MVPA values; the difference in nontransformed MVPA was still statistically significant but likely the result of nonnormally distributed data. Conclusion. The present study suggests that factors other than fatigue might be associated with physical activity and sedentary behavior in MS, and this group might benefit from focal behavioral interventions that take into account mobility status in persons with MS who have fatigue.

Testing Feasibility of a Mobile Application to Monitor Fatigue in People With Multiple Sclerosis

BACKGROUND

Fatigue is a significant and burdensome symptom for patients with multiple sclerosis and is associated with other symptoms, signs, and decreased quality of life.

METHODS

A prospective pilot study was conducted with a convenience sample (n = 34) of patients with relapsing-remitting multiple sclerosis using a phone application, FatigueApp.com, to collect data on patient-reported outcome measures (Patient-Reported Outcomes Measurement Information System [PROMIS]).

RESULTS

FatigueApp feasibility was good, with the ability to collect data on self-reported fatigue and other symptoms using PROMIS measures.

CONCLUSIONS

This study showed that using a phone application with PROMIS may be useful in the future to provide estimates of fatigue and other variables to facilitate clinical monitoring of fatigue for neurology clinic settings.

Pain, Fatigue, and Cognitive Symptoms Are Temporally Associated Within but Not Across Days in Multiple Sclerosis

OBJECTIVE

To examine the temporal associations, within day and day to day, between pain, fatigue, depressed mood, and cognitive function in multiple sclerosis (MS).

DESIGN

Repeated-measures study involving 7 days of ecological momentary assessment (EMA) of symptoms 5 times a day; multilevel mixed models were used to analyze data.

SETTING

Community.

PARTICIPANTS

Ambulatory adults (N=107) with MS.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

EMA of pain, fatigue, depressed mood, and cognitive function rated on a 0 to 10 scale.

RESULTS

Fatigue and pain were linked within day such that higher pain was associated with higher subsequent fatigue (B=.09, P=.04); likewise, higher fatigue was associated with higher pain in the following time frame (B=.05, P=.04). Poorer perceived cognitive function preceded increased subsequent pain (B=.08, P=.007) and fatigue (B=.10, P=.01) within day. Depressed mood was not temporally linked with other symptoms. In terms of day-to-day effects, a day of higher fatigue related to decreased next day fatigue (B=-.16, P=.01), and a day of higher depressed mood related to increased depressed mood the next day (B=.17, P=.01). There were no cross-symptom associations from one day to the next.

CONCLUSIONS

Findings provide new insights on how common symptoms in MS relate to each other and vary within and over days. Pain and fatigue show evidence of a dynamic bidirectional relation over the course of a day, and worsening of perceived cognitive function preceded worsening of both pain and fatigue. Most temporal associations between symptoms occur within the course of a day, with relatively little carryover from one day to the next.

Ecological Momentary Assessment of Pain, Fatigue, Depressive, and Cognitive Symptoms Reveals Significant Daily Variability in Multiple Sclerosis

OBJECTIVE

To describe the daily variability and patterns of pain, fatigue, depressed mood, and cognitive function in persons with multiple sclerosis (MS).

DESIGN

Repeated-measures observational study of 7 consecutive days of home monitoring, including ecological momentary assessment (EMA) of symptoms. Multilevel mixed models were used to analyze data.

SETTING

General community.

PARTICIPANTS

Ambulatory adults (N=107) with MS recruited through the University of Michigan and surrounding community.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

EMA measures of pain, fatigue, depressed mood, and cognitive function rated on a 0 to 10 scale, collected 5 times a day for 7 days.

RESULTS

Cognitive function and depressed mood exhibited more stable within-person patterns than pain and fatigue, which varied considerably within person. All symptoms increased in intensity across the day (all P<.02), with fatigue showing the most substantial increase. Notably, this diurnal increase varied by sex and age; women showed a continuous increase from wake to bedtime, whereas fatigue plateaued after 7 pm for men (wake-bed B=1.04, P=.004). For the oldest subgroup, diurnal increases were concentrated to the middle of the day compared with younger subgroups, which showed an earlier onset of fatigue increase and sustained increases until bed time (wake-3 pm B=.04, P=.01; wake-7 pm B=.03, P=.02). Diurnal patterns of cognitive function varied by education; those with advanced college degrees showed a more stable pattern across the day, with significant differences compared with those with bachelor-level degrees in the evening (wake-7 pm B=-.47, P=.02; wake-bed B=-.45, P=.04).

CONCLUSIONS

Findings suggest that chronic symptoms in MS are not static, even over a short time frame; rather, symptoms-fatigue and pain in particular-vary dynamically across and within days. Incorporation of EMA methods should be considered in the assessment of these chronic MS symptoms to enhance assessment and treatment strategies.