Physical Activity Measures in Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Correlations Between Peak Oxygen Consumption, the Physical Functioning Scale of the SF-36 Questionnaire, and the Number of Steps From an Activity Meter

Abstract:

Background: Most studies to assess effort intolerance in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have used questionnaires. Few studies have compared questionnaires with objective measures like an actometer or an exercise test. This study compared three measures of physical activity in ME/CFS patients: the physical functioning scale (PFS) of the SF-36, the number of steps/day (Steps) using an actometer, and the %peak VO2 of a cardiopulmonary stress test.

Methods: Female ME/CFS patients were selected from a clinical database if the three types of measurements were available, and the interval between measurements was ≤ 3 months. Data from the three measures were compared by linear regression.

Results: In 99 female patients the three different measures were linearly, significantly, and positively correlated (PFS vs Steps, PFS vs %peak VO2 and Steps vs %peak VO2: all P < 0.001). Subgroup analysis showed that the relations between the three measures were not different in patients with versus without fibromyalgia and with versus without a maximal exercise effort (RER ≥ 1.1). In 20 patients re-evaluated for symptom worsening, the mean of all three measures was significantly lower (P < 0.0001), strengthening the observation of the relations between them. Despite the close correlation, we observed a large variation between the three measures in individual patients.

Conclusions: Given the large variation in ME/CFS patients, the use of only one type of measurement is inadequate. Integrating the three modalities may be useful for patient care by detecting overt discrepancies in activity and may inform studies that compare methods of improving exercise capacity.

Source: van Campen CMC, Rowe PC, Verheugt FWA, Visser FC. Physical activity measures in patients with myalgic encephalomyelitis/chronic fatigue syndrome: correlations between peak oxygen consumption, the physical functioning scale of the SF-36 questionnaire, and the number of steps from an activity meter. J Transl Med. 2020;18(1):228. Published 2020 Jun 8. doi:10.1186/s12967-020-02397-7 https://pubmed.ncbi.nlm.nih.gov/32513266/

Assessing functioning in adolescents with chronic fatigue syndrome: psychometric properties and factor structure of the School and Social Adjustment Scale and the Physical Functioning Subscale of the SF36

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) has a major impact on functioning. However, no validated measures of functioning for this population exist.

AIMS: We aimed to establish the psychometric properties of the 5-item School and Social Adjustment Scale (SSAS) and the 10-item Physical Functioning Subscale of the SF-36 in adolescents with CFS.

METHOD: Measures were completed by adolescents with CFS (n = 121).

RESULTS: For the Physical Functioning Subscale, a 2-factor solution provided a close fit to the data. Internal consistency was satisfactory. For the SSAS, a 1-factor solution provided an adequate fit to the data. The internal consistency was satisfactory. Inter-item and item-total correlations did not indicate any problematic items and functioning scores were moderately correlated with other measures of disability, providing evidence of construct validity.

CONCLUSION: Both measures were found to be reliable and valid and provide brief measures for assessing these important outcomes. The Physical Functioning Subscale can be used as two subscales in adolescents with CFS.

Source: Loades ME, Vitoratou S, Rimes KA, Chalder T. Assessing functioning in adolescents with chronic fatigue syndrome: psychometric properties and factor structure of the School and Social Adjustment Scale and the Physical Functioning Subscale of the SF36. Behav Cogn Psychother. 2020 Apr 1:1-11. doi: 10.1017/S1352465820000193. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/32234097

Health-related quality of life in patients with myalgic encephalomyelitis/chronic fatigue syndrome: an Australian cross-sectional study.

Abstract:

BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious and debilitating disorder associated with significant disruptions in daily life including. This study aimed to examine the impact of sociodemographic and patient symptom characteristics on health-related quality of life (HRQoL) of Australians with ME/CFS.

METHODS: Self-reported data collected from 480 individuals diagnosed with ME/CFS were obtained between August 2014 and August 2018. This cross-sectional survey analysed sociodemographic, symptom characteristics and HRQoL according to the 36-Item Health Survey (SF-36). Multivariate linear regression models were used to determine ME/CFS symptoms associated with eight domains of HRQoL.

RESULTS: Reported HRQoL was significantly impaired in ME/CFS patients across all domains compared with the general population. Scores were the lowest for physical role (4.11 ± 15.07) and energy/fatigue (13.54 ± 13.94). Associations with females, higher body mass index (BMI), employment status, cognitive difficulties, sensory disturbances and cardiovascular symptoms were observed in the physical functioning domain. Impaired pain domain scores were associated with high BMI, annual visits to their general practitioner, flu-like symptoms and fluctuations in body temperature. Reduced well-being scores were associated with smoking status, psychiatric comorbidity, cognitive difficulties, sleep disturbances and gastrointestinal difficulties.

CONCLUSION: This study provides evidence that ME/CFS has a profound and negative impact on HRQoL in an Australian cohort.

Source: Eaton-Fitch N, Johnston SC, Zalewski P, Staines D, Marshall-Gradisnik S. Health-related quality of life in patients with myalgic encephalomyelitis/chronic fatigue syndrome: an Australian cross-sectional study. Qual Life Res. 2020 Jan 22. doi: 10.1007/s11136-019-02411-6. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31970624

Assessing chronic fatigue syndrome: Self-reported physical functioning and correlations with physical testing

Abstract:

The pathophysiology of chronic fatigue syndrome (CFS) remains unclear; no biomarkers have thus far been identified or physical tests designed to underpin its diagnosis. Assessment mainly uses Fukuda’s criteria and is based on the exclusion of symptoms related to other diseases/syndromes, subjective self-reporting, and outcomes of self-report questionnaires.

In order to improve the baseline assessment and progress evaluation of individuals suspected of CFS and using an association-oriented research strategy and a cross-correlational design, this study investigates possible associations between the performance on two physical tests, i.e. ‘Timed Loaded Standing’ (TLS), assessing trunk-arm endurance, and the ‘Stops Walking with Eyes Closed while performing a secondary Cognitive Task’ (SWECCT), measuring impaired automaticity of gait, and the results of two self-report questionnaires, the Checklist Individual Strength (CIS, total score and fatigue subscale score) and the physical functioning and vitality subscales of the Short Form Health Survey (SF-36) to gauge the participants’ subjective feelings of fatigue and beliefs regarding their abilities to perform daily-life activities.

Comparisons of the outcomes obtained in 27 female patients with a confirmed diagnosis of CFS revealed that trunk-arm endurance as measured with the TLS correlated with the SF-36 physical functioning subscale only (raw p value: 0.004). None of the other correlations were statistically significant. It is concluded that the TLS may have potential as an objective assessment tool to support the diagnosis and monitoring of treatment effects in CFS.

Copyright © 2019 Elsevier Ltd. All rights reserved.

Source: Eyskens JB, Illegems J, De Nil L, Nijs J, Kampen JK, Moorkens G. Assessing chronic fatigue syndrome: Self-reported physical functioning and correlations with physical testing. J Bodyw Mov Ther. 2019 Jul;23(3):598-603. doi: 10.1016/j.jbmt.2019.03.006. Epub 2019 Mar 16. https://www.ncbi.nlm.nih.gov/pubmed/31563377

Defining the minimally clinically important difference of the SF-36 physical function subscale for paediatric CFS/ME: triangulation using three different methods

Abstract:

BACKGROUND: Defining the minimally clinically important difference (MCID) is important for the design and analysis of clinical trials and ensures that findings are clinically meaningful. Studies in adult populations have investigated the MCID of The Short Form 36 physical function sub-scale (SF-36-PFS). However, to our knowledge no studies have defined the MCID of the SF-36-PFS in a paediatric population. We aimed to triangulate findings from distribution, anchor and qualitative methods to identify the MCID of the SF-36-PFS for children and adolescents with CFS/ME.

METHODS: Quantitative methods: We analysed routinely-collected data from a specialist paediatric CFS/ME service in South-West England using: 1) the anchor method, based on Clinical Global Impression (CGI) outcomes at 6 months’ follow-up; 2) the distribution method, based on the standard deviation of baseline SF-36-PFS scores. Qualitative methods: Young people (aged 12-17 years) and parents were asked to complete the SF-36-PFS, marking each question twice: once for where they would currently rate themselves/their child and a second time to show what they felt would be the smallest amount of change for them/their child to feel treatment had made a difference. Semi-structured interviews were designed to explore what factors were deemed important to patients and to what extent an improvement was considered satisfactory. We thematically analysed qualitative interviews from 21 children and their parents.

RESULTS: Quantitative results: Six-month follow-up data were available for 198 children with a mean age of 14 years. Most were female (74%, 146/198) and 95% gave their ethnicity as “White British”. Half the standard deviation of the baseline SF-36-PFS scores was 11.0. “A little better” on the CGI equated to a mean difference on the SF-36-PFS from baseline to 6-month follow-up of 9.0. Qualitative results: Twenty-one children with CFS/ME participated: 16 females (76.2%) with a mean age of 14.4 years. Twenty mothers and two fathers were also interviewed. The median minimal improvement in the SF-36-PFS was 10. Participants indicated that small changes in physical function can lead to important improvements in valued social and family function. Patients and parents were positive about improvement even in the presence of persisting symptoms. Triangulation: The MCID based on the mean score from the three methods was 10.

CONCLUSIONS: Converging evidence indicates future studies in paediatric CFS/ME should use an MCID of 10 on the SF-36-PFS.

Source: Brigden A, Parslow RM, Gaunt D, Collin SM, Jones A, Crawley E. Defining the minimally clinically important difference of the SF-36 physical function subscale for paediatric CFS/ME: triangulation using three different methods. Health Qual Life Outcomes. 2018 Oct 19;16(1):202. doi: 10.1186/s12955-018-1028-2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6194701/ (Full article)

Assessing current functioning as a measure of significant reduction in activity level

Abstract:

BACKGROUND: Myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) have case definitions with varying criteria, but almost all criteria require an individual to have a substantial reduction in activity level. Unfortunately, a consensus has not been reached regarding what constitutes substantial reductions. One measure that has been used to measure substantial reduction is the Medical Outcomes Study Short Form-36 Health Survey (SF-36).[1].

PURPOSE: The current study examined the relationship between the SF-36, a measure of current functioning, and a self-report measure of the percent reduction in hours spent on activities.

RESULTS: Findings indicated that select subscales of the SF-36 accurately measure significant reductions in functioning. Further, this measure significantly differentiates patients from controls.

CONCLUSION: Determining what constitutes a significant reduction in activity is difficult because it is subjective to the individual. However, certain subscales of the SF-36 could provide a uniform way to accurately measure and define substantial reductions in functioning.

 

Source: Thorpe T, McManimen S, Gleason K, Stoothoff J, Newton JL, Strand EB, Jason LA. Assessing current functioning as a measure of significant reduction in activity level. Fatigue. 2016;4(3):175-188. doi: 10.1080/21641846.2016.1206176. Epub 2016 Jul 19. https://www.ncbi.nlm.nih.gov/pubmed/28217427

 

Reliability and validity of Short Form 36 Version 2 to measure health perceptions in a sub-group of individuals with fatigue

Abstract:

PURPOSE: To determine the validity and reliability of Short Form 36 Version 2 (SF36v2) in sub-groups of individuals with fatigue.

METHOD: Thirty subjects participated in this study, including n = 16 subjects who met case definition criteria for chronic fatigue syndrome (CFS) and n = 14 non-disabled sedentary matched control subjects. SF36v2 and Multidimensional Fatigue Inventory (MFI-20) were administered before two maximal cardiopulmonary exercise tests (CPETs) administered 24 h apart and an open-ended recovery questionnaire was administered 7 days after CPET challenge. The main outcome measures were self-reported time to recover to pre-challenge functional and symptom status, frequency of post-exertional symptoms and SF36v2 sub-scale scores.

RESULTS: Individuals with CFS demonstrated significantly lower SF36v2 and MFI-20 sub-scale scores prior to CPET. Between-group differences remained significant post-CPET, however, there were no significant group by test interaction effects. Subjects with CFS reported significantly more total symptoms (p < 0.001), as well as reports of fatigue (p < 0.001), neuroendocrine (p < 0.001), immune (p < 0.01), pain (p < 0.01) and sleep disturbance (p < 0.01) symptoms than control subjects as a result of CPET. Many symptom counts demonstrated significant relationships with SF36v2 sub-scale scores (p < 0.05). SF36v2 and MFI-20 sub-scale scores demonstrated significant correlations (p < 0.05). Various SF36v2 sub-scale scores demonstrated significant predictive validity to identify subjects who recovered from CPET challenge within 1 day and 7 days (p < 0.05). Potential floor effects were observed for both questionnaires for individuals with CFS.

CONCLUSION: Various sub-scales of SF36v2 demonstrated adequate reliability and validity for clinical and research applications. Adequacy of sensitivity to change of SF36v2 as a result of a fatiguing stressor should be the subject of additional study.

 

Source: Davenport TE, Stevens SR, Baroni K, Van Ness JM, Snell CR. Reliability and validity of Short Form 36 Version 2 to measure health perceptions in a sub-group of individuals with fatigue. Disabil Rehabil. 2011;33(25-26):2596-604. doi: 10.3109/09638288.2011.582925. Epub 2011 Jun 20. https://www.ncbi.nlm.nih.gov/pubmed/21682669

 

Measuring substantial reductions in functioning in patients with chronic fatigue syndrome

Abstract:

PURPOSE: All the major current case definitions for chronic fatigue syndrome (CFS) specify substantial reductions in previous levels of occupational, educational, social, or personal activities to meet criteria. Difficulties have been encountered in operationalizing ‘substantial reductions.’ For example, the Medical Outcomes Study Short Form-36 Health Survey (SF-36) has been used to determine whether individuals met the CFS disability criterion. However, previous methods of using the SF-36 have been prone to including people without substantial reductions in key areas of physical functioning when diagnosing CFS. This study sought to empirically identify the most appropriate SF-36 subscales for measuring substantial reductions in patients with CFS.

METHOD: The SF-36 was administered to two samples of patients with CFS: one recruited from tertiary care and the other a community-based sample; as well as a non-fatigued control group. Receiver operating characteristics were used to determine the optimal cutoff scores for identifying patients with CFS.

RESULTS: The SF-36 Role-Emotional subscale had the worst sensitivity and specificity, whereas the Vitality, Role-Physical, and Social Functioning subscales had the best sensitivity and specificity.

CONCLUSION: Based on the evidence from this study, the potential criteria for defining substantial reductions in functioning and diagnosing CFS is provided.

© 2011 Informa UK, Ltd.

 

Source: Jason L, Brown M, Evans M, Anderson V, Lerch A, Brown A, Hunnell J, Porter N. Measuring substantial reductions in functioning in patients with chronic fatigue syndrome. Disabil Rehabil. 2011;33(7):589-98. doi: 10.3109/09638288.2010.503256. Epub 2010 Jul 9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3170036/ (Full article)

 

Employment status in chronic fatigue syndrome. A cross-sectional study examining the value of exercise testing and self-reported measures for the assessment of employment status

Abstract:

OBJECTIVE: To examine the value of exercise testing and self-reported disability for the assessment of employment status in patients with chronic fatigue syndrome.

DESIGN: Cross-sectional observational study.

SETTING: A university-based chronic fatigue clinic.

SUBJECTS: Fifty-four consecutive, Flemish, employed (not self-employed) chronic fatigue syndrome patients (49/54 female).

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Participants were questioned about their current and premorbid employment status, filled in the Chronic Fatigue Syndrome Activities and Participation Questionnaire (CFS-APQ), the Medical Outcomes Short Form 36 Health Status Survey (SF-36), and performed a maximal exercise test on a bicycle ergometer with continuous monitoring of cardiorespiratory variables.

RESULTS: A significant association was observed between the current employment rate and two SF-36 subscales (i.e., role limitations due to physical functioning and social functioning; rho = 0.39 and 0.35 respectively) (n = 54). Analysing only the female chronic fatigue syndrome patients (n = 49), the current employment rate correlated significantly with the peak workload (rho = 0.38).

CONCLUSIONS: The associations between either exercise testing or self-reported disability and employment status are too weak to predict employment status.

 

Source: Nijs J, Van de Putte K, Louckx F, De Meirleir K. Employment status in chronic fatigue syndrome. A cross-sectional study examining the value of exercise testing and self-reported measures for the assessment of employment status. Clin Rehabil. 2005 Dec;19(8):895-9. http://www.ncbi.nlm.nih.gov/pubmed/16323389

 

A pilot randomized controlled trial of dexamphetamine in patients with chronic fatigue syndrome

Abstract:

This study determined whether dexamphetamine improved symptoms and quality of life in patients with chronic fatigue syndrome. The setting was a specialized clinic within a tertiary referral hospital. This was a 6-week parallel-group, placebo-controlled trial with random allocation. There was a 2-week dose-adjustment phase and a 4-week stable treatment period. Outcome measures were the Fatigue Severity Scale, the Medical Outcomes Study 36-item Short-Form Health Survey, and two patient-determined outcomes. Ten patients were randomly assigned to dexamphetamine, and 10 were assigned to placebo. Fatigue Severity Scale scores improved in nine of 10 dexamphetamine and four of 10 placebo patients. The change in mean score was statistically significant. There were large but statistically nonsignificant changes in scores for the Short-Form Health Survey domains vitality and physical functioning. Dexamphetamine may be useful in the management of chronic fatigue syndrome; a larger and longer trial is justified by these results.

 

Source: Olson LG, Ambrogetti A, Sutherland DC. A pilot randomized controlled trial of dexamphetamine in patients with chronic fatigue syndrome. Psychosomatics. 2003 Jan-Feb;44(1):38-43. http://www.ncbi.nlm.nih.gov/pubmed/12515836