Category: Methodology

Clinical History Segment Extraction From Chronic Fatigue Syndrome Assessments to Model Disease Trajectories

Abstract:

Chronic fatigue syndrome (CFS) is a long-term illness with a wide range of symptoms and condition trajectories. To improve the understanding of these, automated analysis of large amounts of patient data holds promise. Routinely documented assessments are useful for large-scale analysis, however relevant information is mainly in free text. As a first step to extract symptom and condition trajectories, natural language processing (NLP) methods are useful to identify important textual content and relevant information. In this paper, we propose an agnostic NLP method of extracting segments of patients’ clinical histories in CFS assessments. Moreover, we present initial results on the advantage of using these segments to quantify and analyse the presence of certain clinically relevant concepts.

Source: Priou S, Viani N, Vernugopan V, et al. Clinical History Segment Extraction from Chronic Fatigue Syndrome Assessments to Model Disease Trajectories. Stud Health Technol Inform. 2020;270:98-102. doi:10.3233/SHTI200130 https://pubmed.ncbi.nlm.nih.gov/32570354/

Properties of Measurements Obtained During Cardiopulmonary Exercise Testing in Individuals With Myalgic encephalomyelitis/chronic Fatigue Syndrome

Abstract:

Background: Diminished cardiopulmonary exercise test (CPET) performance indicates the physiological basis for reduced capacity for activities of daily living and work. Thus, it may be a biomarker for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Objective: To determine statistical properties of cardiac, pulmonary, and metabolic measurements obtained during CPET in people with ME/CFS.

Methods: Fifty-one females with ME/CFS and 10 sedentary females with similar age and body mass received cardiac, pulmonary, and metabolic measurements during 2 CPETs separated by 24 hours. Two-way analysis of variance and effect size calculations (Cohen’s d) were used to assess the magnitude and statistical significance of differences in measurements between groups. Reliability of CPET measurements was estimated using intraclass correlation coefficients (formula 2,1; ICC2,1). Responsiveness of CPET measurements was assessed using minimum detectable change outside the 95% confidence interval (MDC95) and coefficients of variation (CoV).

Results: CPET measurements demonstrated moderate to high reliability for individuals with ME/CFS. Comparing subjects with ME/CFS and control subjects yielded moderate to large effect sizes on all CPET measurements. MDC95 for all individuals with ME/CFS generally exceeded control subjects and CoVs for CPET measurements were comparable between groups.

Conclusions: CPET measurements demonstrate adequate responsiveness and reproducibility for research and clinical applications.

Source: Davenport TE, Stevens SR, Stevens MAJ, Snell CR, Van Ness JM. Properties of measurements obtained during cardiopulmonary exercise testing in individuals with myalgic encephalomyelitis/chronic fatigue syndrome [published online ahead of print, 2020 Jun 16]. Work. 2020;10.3233/WOR-203170. doi:10.3233/WOR-203170

Clinically Accessible Tools for Documenting the Impact of Orthostatic Intolerance on Symptoms and Function in ME/CFS

Abstract:

Background: Clinical observations have indicated that hours of upright activity (HUA) reported by Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients correlated with orthostatic symptoms and impaired physical function. This study examined the relationship between HUA and orthostatic intolerance (OI).

Methods: Twenty-five female ME/CFS subjects and 25 age and race matched female healthy controls (HCs) were enrolled. Subjects reported HUA (defined as hours per day spent with feet on the floor) and completed questionnaires to assess the impact of OI on daily activities and symptoms. ME/CFS patients were categorized into those with <5 HUA and ≥5 HUA and analyzed by employment status. Data analysis used one-way ANOVA.

Results: ME/CFS patients had fewer HUA, worse symptoms and greater interference with daily activities due to OI than HCs. The <5 HUA ME/CFS subjects had more severe OI related symptoms than ≥5 HUA ME/CFS subjects even though OI interfered with daily activities similarly. Only 33% of ME/CFS subjects were employed and all were ≥5 HUA ME/CFS subjects with an average HUA of 8.

Conclusions: ME/CFS subjects experienced more frequent and severe OI symptoms, higher interference with daily activities, and reduced ability to work than HCs. Reported HUA and assessment of OI using standardized instruments may be useful clinical tools for physicians in the diagnosis, treatment and management of ME/CFS patients.

Source: Lee J, Wall P, Kimler C, Bateman L, Vernon SD. Clinically accessible tools for documenting the impact of orthostatic intolerance on symptoms and function in ME/CFS [published online ahead of print, 2020 Jun 16]. Work. 2020;10.3233/WOR-203169. doi:10.3233/WOR-203169 https://pubmed.ncbi.nlm.nih.gov/32568144/

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/

Symptom frequency and development of a generic functional disorder symptom scale suitable for use in studies of patients with irritable bowel syndrome, fibromyalgia syndrome or chronic fatigue syndrome

Abstract:

OBJECTIVES: To describe the extent to which irritable bowel syndrome (IBS), fibromyalgia syndrome (FMS), and chronic fatigue syndrome (CFS) exhibit symptom overlap, and to validate a patient-derived, generic symptom questionnaire.

METHODS: A patient-derived 61-item symptom-frequency questionnaire was completed by participants recruited through IBS, FMS and CFS self-help websites. Principal axis factor analysis with oblimin rotation was performed separately for those reporting an IBS, FMS or CFS diagnosis.

RESULTS: Questionnaires were completed by 1751 participants of whom 851 reported more than one of the three diagnoses. Stomach pain on at least a weekly basis was reported by 79% of IBS, 52% of FMS, and 43% of CFS single diagnosis participants. Pain increasing the day after activity was reported by 32% of IBS, 94% of FMS, and 85% of CFS single diagnosis participants. Waking still tired at least once weekly was reported by 75% of IBS, 97% of FMS, and 95% of CFS single diagnosis participants. Exploratory factor analysis produced consistent results across all three diagnostic groups, the 61 items loading on 12 correlated factors with a single higher order factor on which all items loaded. Frequency analysis led to the rejection of one item (cold sores on or near lips), and freeform reporting by participants of additional symptoms identified an additional five, namely, restless legs, hair loss/brittle hair/thinning, dizziness/balance problems, blurred vision and urination problems.

CONCLUSIONS: IBS, FMS and CFS are polysymptomatic spectrum disorders with a wide range of overlapping symptoms, many of which are unrelated to diagnostic criteria. Frequency analysis and factor analysis confirm the validity of using the same questionnaire across different diagnostic categories. The 65-item general symptom questionnaire (GSQ-65) is a valid generic symptom scale suitable for assessing the many different symptoms of people with IBS, FMS and CFS.

Source: Hyland ME, Bacon AM, Lanario JW, Davies AF. Symptom frequency and development of a generic functional disorder symptom scale suitable for use in studies of patients with irritable bowel syndrome, fibromyalgia syndrome or chronic fatigue syndrome. Chronic Dis Transl Med. 2019 Jun 24;5(2):129-138. doi: 10.1016/j.cdtm.2019.05.003. eCollection 2019 Jun. https://www.sciencedirect.com/science/article/pii/S2095882X18300987?via%3Dihub (Full article)

“It’s not one size fits all”; the use of videoconferencing for delivering therapy in a Specialist Paediatric Chronic Fatigue Service

Abstract:

BACKGROUND: There are few specialist paediatric Chronic Fatigue Syndrome (CFS/ME) services in the UK. Therefore, the distance some families have to travel to reach these services can be a barrier to accessing evidence-based treatment. Videoconferencing technology such as Skype provides a means of delivering sessions remotely. This study aimed to explore the views of children and young people, their parents, and healthcare professionals of treatment delivered by videoconferencing in a specialist paediatric CFS/ME team.

METHOD: To explore the experiences of the participants, a qualitative design was selected. Twelve young people (age 9-18), and 6 parents were interviewed about their experience of treatment sessions delivered via videoconferencing within a specialist CFS/ME service. A focus group explored the views of healthcare professionals (N = 9) from the service. Thematic analysis was used.

RESULTS: Three themes were identified from the data: “Challenges and concerns”, “Benefits” and “Treatment provision”. Challenges and concerns that participants identified were; difficulties experienced with technology; a sense of a part of communication being lost with virtual connections; privacy issues with communicating online and feeling anxious on a screen. Participants felt that benefits of videoconferencing were; improving access to the chronic fatigue service; convenience and flexibility of treatment provision; a sense of being more open online and being in the comfort of their own home. In terms of treatment provision participants talked about videoconferencing as a part of a hierarchy of communication; the function of videoconferencing within the context of the chronic fatigue service; additional preparation needed to utilise videoconferencing and an assumption that videoconferencing is “part of young people’s lives”.

CONCLUSIONS: Although the experience of sessions provided by videoconferencing was different to sessions attended in person, participants tended to be positive about videoconferencing as an alternative means of accessing treatment, despite some barriers. Videoconferencing could be an additional option within an individualised care plan, but should not be an alternative to face to face support.

Source: Haig-Ferguson A, Loades M, Whittle C, Read R, Higson-Sweeney N, Beasant L, Starbuck J, Crawley E. “It’s not one size fits all”; the use of videoconferencing for delivering therapy in a Specialist Paediatric Chronic Fatigue Service. Internet Interv. 2018 Dec 23;15:43-51. doi: 10.1016/j.invent.2018.12.003. eCollection 2019 Mar. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6312867/ (Full article)

Neuroinflammation and Cytokines in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Critical Review of Research Methods

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is the label given to a syndrome that can include long-term flu-like symptoms, profound fatigue, trouble concentrating, and autonomic problems, all of which worsen after exertion. It is unclear how many individuals with this diagnosis are suffering from the same condition or have the same underlying pathophysiology, and the discovery of biomarkers would be clarifying.

The name “myalgic encephalomyelitis” essentially means “muscle pain related to central nervous system inflammation” and many efforts to find diagnostic biomarkers have focused on one or more aspects of neuroinflammation, from periphery to brain. As the field uncovers the relationship between the symptoms of this condition and neuroinflammation, attention must be paid to the biological mechanisms of neuroinflammation and issues with its potential measurement.

The current review focuses on three methods used to study putative neuroinflammation in ME/CFS: (1) positron emission tomography (PET) neuroimaging using translocator protein (TSPO) binding radioligand (2) magnetic resonance spectroscopy (MRS) neuroimaging and (3) assays of cytokines circulating in blood and cerebrospinal fluid. PET scanning using TSPO-binding radioligand is a promising option for studies of neuroinflammation. However, methodological difficulties that exist both in this particular technique and across the ME/CFS neuroimaging literature must be addressed for any results to be interpretable.

We argue that the vast majority of ME/CFS neuroimaging has failed to use optimal techniques for studying brainstem, despite its probable centrality to any neuroinflammatory causes or autonomic effects. MRS is discussed as a less informative but more widely available, less invasive, and less expensive option for imaging neuroinflammation, and existing studies using MRS neuroimaging are reviewed. Studies seeking to find a peripheral circulating cytokine “profile” for ME/CFS are reviewed, with attention paid to the biological and methodological reasons for lack of replication among these studies.

We argue that both the biological mechanisms of cytokines and the innumerable sources of potential variance in their measurement make it unlikely that a consistent and replicable diagnostic cytokine profile will ever be discovered.

Source: Michael B. VanElzakker, Sydney A. Brumfield and Paula S. Lara Mejia. Neuroinflammation and Cytokines in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Critical Review of Research Methods. Front. Neurol., 10 January 2019 | https://doi.org/10.3389/fneur.2018.01033 https://www.frontiersin.org/articles/10.3389/fneur.2018.01033/full?fbclid=IwAR3KxhofUaLakZRPNiyBliNHSlJvUOdsVqVf5cED_i6o5gF9MCbWxpeS298#h7 (Full article)

The Development of the DePaul Symptom Questionnaire: Original, Expanded, Brief, and Pediatric Versions

Abstract:

One of the key requirements of a reliable case definition is the use of standardized procedures for assessing symptoms. This article chronicles the development of the DePaul Symptom Questionnaire (DSQ) to assess symptoms of the major chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME) case definitions.

The original questionnaire has been modified and expanded over time to more fully capture symptoms from various adult case definitions, and a brief as well as pediatric version have also been developed. The DSQ has demonstrated very good psychometric properties in terms of test-retest reliability and sensitivity/specificity, as well as construct, predictive, and discriminant validity. The DSQ allows for a clear characterization of a patient’s illness and allows scientists and clinicians to improve diagnostic reliability and validity when employing case definitions of ME and CFS.

Source: Jason LA, Sunnquist M. The Development of the DePaul Symptom Questionnaire: Original, Expanded, Brief, and Pediatric Versions. Front Pediatr. 2018 Nov 6;6:330. doi: 10.3389/fped.2018.00330. eCollection 2018.  https://www.ncbi.nlm.nih.gov/pubmed/30460215

The development of an instrument to assess post-exertional malaise in patients with myalgic encephalomyelitis and chronic fatigue syndrome

Abstract:

Post-exertional malaise, or a variation of this term, is a key symptom of myalgic encephalomyelitis and chronic fatigue syndrome, as this symptom is mentioned in almost all myalgic encephalomyelitis and chronic fatigue syndrome case definitions. Until now there has not been a comprehensive questionnaire to assess post-exertional malaise. To rectify this situation, in this article we describe the development of a new questionnaire, called the DePaul Post-Exertional Malaise Questionnaire, which was based on input from hundreds of patients. Preliminary validation was provided by the findings of significant and predictable relationships between different domains of this post-exertional malaise questionnaire and physical functioning.

Source: Jason LA, Holtzman CS, Sunnquist M, Cotler J. The development of an instrument to assess post-exertional malaise in patients with myalgic encephalomyelitis and chronic fatigue syndrome. J Health Psychol. 2018 Oct 24:1359105318805819. doi: 10.1177/1359105318805819. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/30354489

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)