Mixed methods system for the assessment of post-exertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: an exploratory study

Background

A central feature of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is post-exertional malaise (PEM), which is an acute worsening of symptoms after a physical, emotional and/or mental exertion. Dynamic measures of PEM have historically included scaled questionnaires, which have not been validated in ME/CFS. To enhance our understanding of PEM and how best to measure it, we conducted semistructured qualitative interviews (QIs) at the same intervals as visual analogue scale (VAS) measures after a cardiopulmonary exercise test (CPET).

Methods

Ten ME/CFS and nine healthy volunteers participated in a CPET. For each volunteer, PEM symptom VAS (12 symptoms) and semistructured QIs were administered at six timepoints over 72 hours before and after a single CPET. QI data were used to plot the severity of PEM at each time point and identify the self-described most bothersome symptom for each ME/CFS volunteer. Performance of QI and VAS data was compared with each other using Spearman correlations.

Results

Each ME/CFS volunteer had a unique PEM experience, with differences noted in the onset, severity, trajectory over time and most bothersome symptom. No healthy volunteers experienced PEM. QI and VAS fatigue data corresponded well an hour prior to exercise (pre-CPET, r=0.7) but poorly at peak PEM (r=0.28) and with the change from pre-CPET to peak (r=0.20). When the most bothersome symptom identified from QIs was used, these correlations improved (r=0.0.77, 0.42. and 0.54, respectively) and reduced the observed VAS scale ceiling effects.

Conclusion

In this exploratory study, QIs were able to capture changes in PEM severity and symptom quality over time, even when VAS scales failed to do so. Measurement of PEM can be improved by using a quantitative-qualitative mixed model approach.

Cognitive behavioural therapy for neurologists

In neurological practice, we take pride in accurate diagnosis and using neuroscience to develop novel disease-modifying therapies, but we sometimes neglect symptom management and the treatment of distress. Most patients with neurological disorders report that their mental health needs are not being met. Of the many forms of psychological therapy, cognitive behavioural therapy (CBT) is the most likely to be available to our patients. This article sets out to answer the following questions: (1) What is CBT? (2) What will patients experience if they have CBT? (3) Is CBT effective for people with neurological disorders? (4) Who is most suitable for CBT? (5) How and where can a neurologist refer their patients for CBT? (6) Can we as neurologists use aspects of the CBT model in our own consultations?

Anomalies in the review process and interpretation of the evidence in the NICE guideline for chronic fatigue syndrome and myalgic encephalomyelitis

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a disabling long-term condition of unknown cause. The National Institute for Health and Care Excellence (NICE) published a guideline in 2021 that highlighted the seriousness of the condition, but also recommended that graded exercise therapy (GET) should not be used and cognitive-behavioural therapy should only be used to manage symptoms and reduce distress, not to aid recovery. This U-turn in recommendations from the previous 2007 guideline is controversial.We suggest that the controversy stems from anomalies in both processing and interpretation of the evidence by the NICE committee. The committee: (1) created a new definition of CFS/ME, which 'downgraded' the certainty of trial evidence; (2) omitted data from standard trial end points used to assess efficacy; (3) discounted trial data when assessing treatment harm in favour of lower quality surveys and qualitative studies; (4) minimised the importance of fatigue as an outcome; (5) did not use accepted practices to synthesise trial evidence adequately using GRADE (Grading of Recommendations, Assessment, Development and Evaluations trial evidence); (6) interpreted GET as mandating fixed increments of change when trials defined it as collaborative, negotiated and symptom dependent; (7) deviated from NICE recommendations of rehabilitation for related conditions, such as chronic primary pain and (8) recommended an energy management approach in the absence of supportive research evidence.We conclude that the dissonance between this and the previous guideline was the result of deviating from usual scientific standards of the NICE process. The consequences of this are that patients may be denied helpful treatments and therefore risk persistent ill health and disability.

Behavioural modification interventions for medically unexplained symptoms in primary care: systematic reviews and economic evaluation

BACKGROUND

The term 'medically unexplained symptoms' is used to cover a wide range of persistent bodily complaints for which adequate examination and appropriate investigations do not reveal sufficiently explanatory structural or other specified pathologies. A wide range of interventions may be delivered to patients presenting with medically unexplained symptoms in primary care. Many of these therapies aim to change the behaviours of the individual who may have worsening symptoms.

OBJECTIVES

An evidence synthesis to determine the clinical effectiveness and cost-effectiveness of behavioural modification interventions for medically unexplained symptoms delivered in primary care settings was undertaken. Barriers to and facilitators of the effectiveness and acceptability of these interventions from the perspective of patients and service providers were evaluated through qualitative review and realist synthesis.

DATA SOURCES

Full search strategies were developed to identify relevant literature. Eleven electronic sources were searched. Eligibility criteria - for the review of clinical effectiveness, randomised controlled trials were sought. For the qualitative review, UK studies of any design were included. For the cost-effectiveness review, papers were restricted to UK studies reporting outcomes as quality-adjusted life-year gains. Clinical searches were conducted in November 2015 and December 2015, qualitative searches were conducted in July 2016 and economic searches were conducted in August 2016. The databases searched included MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO and EMBASE. Updated searches were conducted in February 2019 and March 2019.

PARTICIPANTS

Adult participants meeting the criteria for medically unexplained symptoms, including somatoform disorders, chronic unexplained pain and functional somatic syndromes.

INTERVENTIONS

Behavioural interventions were categorised into types. These included psychotherapies, exercise-based interventions, multimodal therapies (consisting of more than one intervention type), relaxation/stretching/social support/emotional support, guided self-help and general practitioner interventions, such as reattribution. Evidence synthesis: a network meta-analysis was conducted to allow a simultaneous comparison of all evaluated interventions in a single coherent analysis. Separate network meta-analyses were performed at three time points: end of treatment, short-term follow-up (< 6 months since the end of treatment) and long-term follow-up (≥ 6 months after the end of treatment). Outcomes included physical and psychological symptoms, physical functioning and impact of the illness on daily activities. Economic evaluation: within-trial estimates of cost-effectiveness were generated for the subset of studies where utility values (or quality-adjusted life-years) were reported or where these could be estimated by mapping from Short Form questionnaire-36 items or Short Form questionnaire-12 items outcomes.

RESULTS

Fifty-nine studies involving 9077 patients were included in the clinical effectiveness review. There was a large degree of heterogeneity both between and within intervention types, and the networks were sparse across all outcomes. At the end of treatment, behavioural interventions showed some beneficial effects when compared with usual care, in particular for improvement of specific physical symptoms [(1) pain: high-intensity cognitive-behavioural therapy (CBTHI) standardised mean difference (SMD) 0.54 [95% credible interval (CrI) 0.28 to 0.84], multimodal SMD 0.52 (95% CrI 0.19 to 0.89); and (2) fatigue: low-intensity cognitive-behavioural therapy (CBTLI) SMD 0.72 (95% CrI 0.27 to 1.21), relaxation/stretching/social support/emotional support SMD 0.87 (95% CrI 0.20 to 1.55), graded activity SMD 0.51 (95% CrI 0.14 to 0.93), multimodal SMD 0.52 (95% CrI 0.14 to 0.92)] and psychological outcomes [(1) anxiety CBTHI SMD 0.52 (95% CrI 0.06 to 0.96); (2) depression CBTHI SMD 0.80 (95% CrI 0.26 to 1.38); and (3) emotional distress other psychotherapy SMD 0.58 (95% CrI 0.05 to 1.13), relaxation/stretching/social support/emotional support SMD 0.66 (95% CrI 0.18 to 1.28) and sport/exercise SMD 0.49 (95% CrI 0.03 to 1.01)]. At short-term follow-up, behavioural interventions showed some beneficial effects for specific physical symptoms [(1) pain: CBTHI SMD 0.73 (95% CrI 0.10 to 1.39); (2) fatigue: CBTLI SMD 0.62 (95% CrI 0.11 to 1.14), relaxation/stretching/social support/emotional support SMD 0.51 (95% CrI 0.06 to 1.00)] and psychological outcomes [(1) anxiety: CBTHI SMD 0.74 (95% CrI 0.14 to 1.34); (2) depression: CBTHI SMD 0.93 (95% CrI 0.37 to 1.52); and (3) emotional distress: relaxation/stretching/social support/emotional support SMD 0.82 (95% CrI 0.02 to 1.65), multimodal SMD 0.43 (95% CrI 0.04 to 0.91)]. For physical functioning, only multimodal therapy showed beneficial effects: end-of-treatment SMD 0.33 (95% CrI 0.09 to 0.59); and short-term follow-up SMD 0.78 (95% CrI 0.23 to 1.40). For impact on daily activities, CBTHI was the only behavioural intervention to show beneficial effects [end-of-treatment SMD 1.30 (95% CrI 0.59 to 2.00); and short-term follow-up SMD 2.25 (95% CrI 1.34 to 3.16)]. Few effects remained at long-term follow-up. General practitioner interventions showed no significant beneficial effects for any outcome. No intervention group showed conclusive beneficial effects for measures of symptom load (somatisation). A large degree of heterogeneity was found across individual studies in the assessment of cost-effectiveness. Several studies suggested that the interventions produce fewer quality-adjusted life-years than usual care. For those interventions that generated quality-adjusted life-year gains, the mid-point incremental cost-effectiveness ratios (ICERs) ranged from £1397 to £129,267, but, where the mid-point ICER fell below £30,000, the exploratory assessment of uncertainty suggested that it may be above £30,000.

LIMITATIONS

Sparse networks meant that it was not possible to conduct a metaregression to explain between-study differences in effects. Results were not consistent within intervention type, and there were considerable differences in characteristics between studies of the same type. There were moderate to high levels of statistical heterogeneity. Separate analyses were conducted for three time points and, therefore, analyses are not repeated-measures analyses and do not account for correlations between time points.

CONCLUSIONS

Behavioural interventions showed some beneficial effects for specific medically unexplained symptoms, but no one behavioural intervention was effective across all medically unexplained symptoms. There was little evidence that these interventions are effective for measures of symptom load (somatisation). General practitioner-led interventions were not shown to be effective. Considerable heterogeneity in interventions, populations and sparse networks mean that results should be interpreted with caution. The relationship between patient and service provider is perceived to play a key role in facilitating a successful intervention. Future research should focus on testing the therapeutic effects of the general practitioner-patient relationship within trials of behavioural interventions, and explaining the observed between-study differences in effects within the same intervention type (e.g. with more detailed reporting of defined mechanisms of the interventions under study).

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015025520.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 46. See the NIHR Journals Library website for further project information.