The problem of bias in behavioural intervention studies: Lessons from the PACE trial
Abstract:
Geraghty’s recent editorial on the PACE trial for chronic fatigue syndrome has stimulated a lively discussion. Here, I consider whether the published claims are justified by the data. I also discuss wider issues concerning trial procedures, researcher allegiance and participant reporting bias. Cognitive behavioural therapy and graded exercise therapy had modest, time-limited effects on self-report measures, but little effect on more objective measures such as fitness and employment status. Given that the trial was non-blinded, and the favoured treatments were promoted to participants as ‘highly effective’, these effects may reflect participant response bias. In non-blinded trials, the issue of reporting biases deserves greater attention in future.
Source: Carolyn Wilshire. The problem of bias in behavioural intervention studies: Lessons from the PACE trial. Journal of Health Psychology. First published date: March-23-2017. http://journals.sagepub.com/doi/full/10.1177/1359105317700885 (Full article)
PACE team response shows a disregard for the principles of science. Journal of Health Psychology
Abstract:
The PACE trial of cognitive behavioural therapy and graded exercise therapy for chronic fatigue syndrome/myalgic encephalomyelitis has raised serious questions about research methodology. An editorial article by Geraghty gives a fair account of the problems involved, if anything understating the case. The response by White et al. fails to address the key design flaw, of an unblinded study with subjective outcome measures, apparently demonstrating a lack of understanding of basic trial design requirements. The failure of the academic community to recognise the weakness of trials of this type suggests that a major overhaul of quality control is needed.
Source: Jonathan Edwards. PACE team response shows a disregard for the principles of science. Journal of Health Psychology. First published date: March-28-2017. http://journals.sagepub.com/doi/full/10.1177/1359105317700886 (Full article)
The Role of Autonomic Function in Exercise-induced Endogenous Analgesia: A Case-control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndromeand Healthy People
Abstract:
BACKGROUND: Patients with myalgic encephalomyelitis /chronic fatigue syndrome(ME/CFS) are unable to activate brain-orchestrated endogenous analgesia (or descending inhibition) in response to exercise. This physiological impairment is currently regarded as one factor explaining post-exertional malaise in these patients. Autonomic dysfunction is also a feature of ME/CFS.
OBJECTIVES: This study aims to examine the role of the autonomic nervous system in exercise-induced analgesia in healthy people and those with ME/CFS, by studying the recovery of autonomic parameters following aerobic exercise and the relation to changes in self-reported pain intensity.
STUDY DESIGN: A controlled experimental study.
SETTING: The study was conducted at the Human Physiology lab of a University.
METHODS: Twenty women with ME/CFS- and 20 healthy, sedentary controls performed a submaximal bicycle exercise test known as the Aerobic Power Index with continuous cardiorespiratory monitoring. Before and after the exercise, measures of autonomic function (i.e., heart rate variability, blood pressure, and respiration rate) were performed continuously for 10 minutes and self-reported pain levels were registered. The relation between autonomous parameters and self-reported pain parameters was examined using correlation analysis.
RESULTS: Some relationships of moderate strength between autonomic and pain measures were found. The change (post-exercise minus pre-exercise score) in pain severity was correlated (r = .580, P = .007) with the change in diastolic blood pressure in the healthy group. In the ME/CFS group, positive correlations between the changes in pain severity and low frequency (r = .552, P = .014), and between the changes in bodily pain and diastolic blood pressure (r = .472, P = .036), were seen. In addition, in ME/CHFS the change in headache severity was inversely correlated (r = -.480, P = .038) with the change in high frequency heart rate variability.
LIMITATIONS: Based on the cross-sectional design of the study, no firm conclusions can be drawn on the causality of the relations.
CONCLUSIONS: Reduced parasympathetic reactivation during recovery from exercise is associated with the dysfunctional exercise-induced analgesia in ME/CFS. Poor recovery of diastolic blood pressure in response to exercise, with blood pressure remaining elevated, is associated with reductions of pain following exercise in ME/CFS, suggesting a role for the arterial baroreceptors in explaining dysfunctional exercise-induced analgesia in ME/CFS patients.
Source: Oosterwijck JV,Marusic U,De Wandele I,Paul L,Meeus M,Moorkens G,Lambrecht L,Danneels L,Nijs J. The Role of Autonomic Function in Exercise-induced Endogenous Analgesia: A Case-control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndromeand Healthy People. Pain Physician.2017 Mar;20(3):E389-E399. https://www.ncbi.nlm.nih.gov/pubmed/28339438
Multi-Site Clinical Assessment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (MCAM): Design and Implementation of a Prospective/Retrospective Rolling Cohort Study
Abstract:
In the Multi-Site Clinical Assessment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome(MCAM), we relied on expert clinician diagnoses to enroll patients from 7 specialty clinics in the United States in order to perform a systematic collection of data on measures of myalgic encephalomyelitis (ME)/chronic fatigue syndrome(CFS). Healthy persons and those with other illnesses that share some features with ME/CFS were enrolled in comparison groups. The major objectives were to:
1) use standardized questionnaires to measure illness domains of ME/CFS and to evaluate patient heterogeneity overall and between clinics;
2) describe the course of illness, identify the measures that best correlate with meaningful clinical differences, and assess the performances of questionnaires as patient/person-reported outcome measures;
3) describe prescribed medications, orders for laboratory and other tests, and management tools used by expert clinicians to care for persons with ME/CFS;
4) collect biospecimens for future hypothesis testing and for evaluation of morning cortisol profiles; and
5) identify measures that best distinguish persons with ME/CFS from those in the comparison groups and detect subgroups of persons with ME/CFS who may have different underlying causes.
Enrollment began in 2012 and is planned to continue in multiple stages through 2017. We present the MCAM methods in detail, along with an initial description of the 471 patients with ME/CFS who were enrolled in stage 1.
Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US
Source: Unger ER,Lin JS,Tian H,Natelson BH,Lange G,Vu D,Blate M,Klimas NG,Balbin EG,Bateman L,Allen A,Lapp CW,Springs W,Kogelnik AM,Phan CC,Danver J,Podell RN,Fitzpatrick T,Peterson DL,Gottschalk CG,Rajeevan MS;MCAM Study Group. Multi-Site Clinical Assessment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome(MCAM): Design and Implementation of a Prospective/Retrospective Rolling Cohort Study. Am J Epidemiol.2017 Mar 17:1-10. doi: 10.1093/aje/kwx029. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28338983
Acupuncture and moxibustion for chronic fatigue syndrome in traditional Chinese medicine: a systematic review and meta-analysis
Abstract:
BACKGROUND: As the etiology ofchronic fatigue syndrome(CFS) is unclear and the treatment is still a big issue. There exists a wide range of literature about acupuncture and moxibustion (AM) for CFS in traditional Chinese medicine (TCM). But there are certain doubts as well in the effectiveness of its treatment due to the lack of a comprehensive and evidence-based medical proof to dispel the misgivings. Current study evaluated systematically the effectiveness of acupuncture and moxibustion treatments on CFS, and clarified the difference among them and Chinese herbal medicine, western medicine and sham-acupuncture.
METHODS: We comprehensively reviewed literature including PubMed, EMBASE, Cochrane library, CBM (Chinese Biomedical Literature Database) and CNKI (China National Knowledge Infrastructure) up to May 2016, for RCT clinical research on CFS treated by acupuncture and moxibustion. Traditional direct meta-analysis was adopted to analyze the difference between AM and other treatments. Analysis was performed based on the treatment in experiment and control groups. Network meta-analysis was adopted to make comprehensive comparisons between any two kinds of treatments. The primary outcome was total effective rate, while relative risks (RR) and 95% confidence intervals (CI) were used as the final pooled statistics.
RESULTS: A total of 31 randomized controlled trials (RCTs) were enrolled in analyses. In traditional direct meta-analysis, we found that in comparison to Chinese herbal medicine, CbAM (combined acupuncture and moxibustion, which meant two or more types of acupuncture and moxibustion were adopted) had a higher total effective rate (RR (95% CI), 1.17 (1.09 ~ 1.25)). Compared with Chinese herbal medicine, western medicine and sham-acupuncture, SAM (single acupuncture or single moxibustion) had a higher total effective rate, with RR (95% CI) of 1.22 (1.14 ~ 1.30), 1.51 (1.31-1.74), 5.90 (3.64-9.56). In addition, compared with SAM, CbAM had a higher total effective rate (RR (95% CI), 1.23 (1.12 ~ 1.36)). In network meta-analyses, similar results were recorded. Subsequently, we ranked all treatments from high to low effective rate and the order was CbAM, SAM, Chinese herbal medicine, western medicine and sham-acupuncture.
CONCLUSIONS: In the treatment of CFS, CbAM and SAM may have better effect than other treatments. However, the included trials have relatively poor quality, hence high quality studies are needed to confirm our finding.
Source: Wang T,Xu C,Pan K,Xiong H. Acupuncture and moxibustion forchronic fatigue syndromein traditional Chinese medicine: a systematic review and meta-analysis. BMC Complement Altern Med.2017 Mar 23;17(1):163. doi: 10.1186/s12906-017-1647-x. https://www.ncbi.nlm.nih.gov/pubmed/28335756
Can patients with chronic fatigue syndrome really recover after graded exercise or cognitive behavioural therapy? A critical commentary and preliminary re-analysis of the PACE trial
Abstract:
BACKGROUND: Publications from the PACE trial reported that 22% of chronic fatigue syndrome patients recovered following graded exercise therapy (GET), and 22% following a specialised form of CBT. Only 7% recovered in a control, no-therapy group. These figures were based on a definition of recovery that differed markedly from that specified in the trial protocol.
PURPOSE: To evaluate whether these recovery claims are justified by the evidence.
METHODS: Drawing on relevant normative data and other research, we critically examine the researchers’ definition of recovery, and whether the late changes they made to this definition were justified. Finally, we calculate recovery rates based on the original protocol-specified definition.
RESULTS: None of the changes made to PACE recovery criteria were adequately justified. Further, the final definition was so lax that on some criteria, it was possible to score below the level required for trial entry, yet still be counted as ‘recovered’. When recovery was defined according to the original protocol, recovery rates in the GET and CBT groups were low and not significantly higher than in the control group (4%, 7% and 3%, respectively).
CONCLUSIONS: The claim that patients can recover as a result of CBT and GET is not justified by the data, and is highly misleading to clinicians and patients considering these treatments.
Source: Carolyn Wilshire, Tom Kindlon, Alem Matthees & Simon McGrath. Can patients with chronic fatigue syndrome really recover after graded exercise or cognitive behavioural therapy? A critical commentary and preliminary re-analysis of the PACE trial. Fatigue: Biomedicine, Health & Behavior Volume 5, 2017 – Issue 1. http://www.tandfonline.com/doi/full/10.1080/21641846.2017.1259724 (Full article)
PACE trial claims of recovery are not justified by the data: a rejoinder to Sharpe, Chalder, Johnson, Goldsmith and White (2017)
Abstract:
Background:Recently, we critically evaluated the claim from the PACE trial that cognitive behavioural therapy (CBT) and graded exercise therapy (GET) can lead to recovery from chronic fatigue syndrome (CFS). We showed that the trial’s definition of recovery was so loose it failed to capture the term’s core meaning. Also, this definition was substantially loosened very late in the trial, in ways that favoured the study hypotheses. The investigators do not acknowledge any of these criticisms and stand by their original analyses.
Purpose:To examine the arguments advanced in defence of PACE’s recovery claims.
Methods:Drawing on various sources of evidence, we consider three major arguments raised in defence of PACE’s recovery claims: (1) that since there is no agreed definition of recovery, it comes down to a matter of opinion; (2) that the original definition was ‘too stringent’; and (3) the revised definition generates results that align with previous studies.
Results:We find that: (1) ‘recovery’ is a strong claim, which implies evidence a return to health, and that the trial’s final definition did not preserve this core meaning; (2) there is no evidence to suggest that the original protocol-specified definition was ‘too stringent’; (3) absolute recovery rates from other studies are not a legitimate source of support for the recovery definition used.
Conclusions:The PACE trial provides no evidence that CBT and GET can lead to recovery from CFS. The recovery claims made in the PACE trial are therefore misleading for patients and clinicians.
Source: Carolyn Wilshire, Tom Kindlon & Simon McGrath. PACE trial claims of recovery are not justified by the data: a rejoinder to Sharpe, Chalder, Johnson, Goldsmith and White (2017). Fatigue: Biomedicine, Health & Behavior. Volume 5, 2017 – Issue 1. http://www.tandfonline.com/doi/full/10.1080/21641846.2017.1299358
Multimodal and simultaneous assessments of brain and spinal fluid abnormalities inchronic fatigue syndromeand the effects of psychiatric comorbidity
Abstract:
The purpose of this study was to investigate whether CFS patients without comorbid psychiatric diagnoses differ from CFS patients with comorbid psychiatric diagnoses and healthy control subjects in neuropsychological performance, the proportion with elevated spinal fluid protein or white cell counts, cerebral blood flow (CBF), brain ventricular lactate and cortical glutathione (GSH). The results of the study did not show any differences in any of the outcome measures between CFS patients with and without psychiatric comorbidity, thus indicating that psychiatric status may not be an exacerbating factor in CFS.
Importantly, significant differences were found between the pooled samples of CFS compared to controls. These included lower GSH and CBF and higher ventricular lactate and rates of spinal fluid abnormalities in CFS patients compared to healthy controls. Thirteen of 26 patients had abnormal values on two or more of these 4 brain-related variables.
These findings, which replicate the results of several of our prior studies, support the presence of a number of neurobiological and spinal fluid abnormalities in CFS. These results will lead to further investigation into objective biomarkers of the disorder to advance the understanding of CFS.
Copyright © 2017 Elsevier B.V. All rights reserved.
Source: Natelson BH,Mao X,Stegner AJ,Lange G,Vu D,Blate M,Kang G,Soto E,Kapusuz T,Shungu DC. Multimodal and simultaneous assessments of brain and spinal fluid abnormalities inchronic fatigue syndromeand the effects of psychiatric comorbidity. J Neurol Sci.2017 Apr 15;375:411-416. doi: 10.1016/j.jns.2017.02.046. Epub 2017 Feb 22.https://www.ncbi.nlm.nih.gov/pubmed/28320179
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Gulf War Illness patients exhibit increased humoral responses to the Herpesviruses-encoded dUTPase: Implications in disease pathophysiology
Abstract:
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Gulf War Illness (GWI) are debilitating diseases with overlapping symptomology and there are currently no validated tests for definitive diagnosis of either syndrome. While there is evidence supporting the premise that some herpesviruses may act as possible triggers of ME/CFS, the involvement of herpesviruses in the pathophysiology of GWI has not been studied in spite of a higher prevalence of ME/CFS in these patients.
We have previously demonstrated that the deoxyuridine triphosphate nucleotidohydrolases (dUTPase) encoded by Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), and varicella-zoster virus (VZV) possess novel functions in innate and adaptive immunity. The results of this study demonstrate that a significant percentage of patients with ME/CFS (30.91-52.7%) and GWI (29.34%) are simultaneously producing antibodies against multiple human herpesviruses-encoded dUTPases and/or the human dUTPase when compared to controls (17.21%). GWI patients exhibited significantly higher levels of antibodies to the HHV-6 and human dUTPases than controls (p = 0.0053 and p = 0.0036, respectively), while the ME/CFS cohort had higher anti-EBV-dUTPase antibodies than in both GWI patients (p = 0.0008) and controls (p < 0.0001) as well as significantly higher anti-human dUTPase antibodies than in controls (p = 0.0241).
These results suggest that screening of patients’ sera for the presence of various combinations of anti-dUTPase antibodies could be used as potential biomarkers to help identify/distinguish patients with these syndromes and better direct treatment. This article is protected by copyright. All rights reserved.
Source: Halpin P, Williams MV, Klimas NG, Fletcher MA, Barnes Z, Ariza ME.Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Gulf War Illness patients exhibit increased humoral responses to the Herpesviruses-encoded dUTPase: Implications in disease pathophysiology. J Med Virol. 2017 Mar 17. doi: 10.1002/jmv.24810. [Epub ahead of print]https://www.ncbi.nlm.nih.gov/pubmed/28303641
Activin B is a novel biomarker for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) diagnosis: a cross sectional study
Abstract:
Background: Investigations of activin family proteins as serum biomarkers for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). CFS/ME is a disease with complex, wide-ranging symptoms, featuring persistent fatigue of 6 months or longer, particularly post exertion. No definitive biomarkers are available.
Methods: A cross-sectional, observational study of CFS/ME patients fulfilling the 2003 Canadian Consensus Criteria, in parallel with healthy non-fatigued controls, was conducted. Comparisons with a previously defined activin reference population were also performed. For the total study cohort the age range was 18–65 years with a female: male participant ratio of greater than 3:1. All participants were assessed via a primary care community clinic. Blood samples were collected for pathology testing after physical examination and orthostatic intolerance assessment. Cytokines, activin A, activin B and follistatin were also measured in sera from these samples. All data were compared between the CFS/ME and control cohorts, with the activins and follistatin also compared with previously defined reference intervals.
Results: Serum activin B levels for CFS/ME participants were significantly elevated when compared to the study controls, as well as the established reference interval. Serum activin A and follistatin were within their normal ranges. All routine and special pathology markers were within the normal laboratory reference intervals for the total study cohort, with no significant differences detected between CFS/ME and control groups. Also, no significant differences were detected for IL-2, IL-4, IL-6, IL-10, IL-17A, TNF or IFN-gamma.
Conclusion: Elevated activin B levels together with normal activin A levels identified patients with the diagnostic symptoms of CFS/ME, thus providing a novel serum based test. The activins have multiple physiological roles and capture the diverse array of symptoms experienced by CFS/ME patients.
Source:Brett A. Lidbury, Badia Kita, Donald P. Lewis, Susan Hayward, Helen Ludlow, Mark P. Hedger and David M. de Kretser.Activin B is a novel biomarker for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) diagnosis: a cross sectional study. Journal of Translational Medicine 201715:60, DOI: 10.1186/s12967-017-1161-4http://translational-medicine.biomedcentral.com/articles/10.1186/s12967-017-1161-4 (Full article)
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