Adverse outcomes in trials of graded exercise therapy for adult patients with chronic fatigue syndrome.

OBJECTIVES: Graded exercise therapy (GET) is an effective treatment for chronic fatigue syndrome (CFS), but concerns have been raised about its safety. Two randomised controlled trials have not supported these concerns. We further assessed safety outcomes in all ten published trials of GET for CFS. METHODS: We undertook meta-analyses of three outcomes: Self-ratings of Clinical Global Impression (CGI) change scores of 6 or 7 ("much worse" or "very much worse"), numbers of participants withdrawing from treatments, and numbers of participants dropping out of trial follow up. We provide risk ratios (95% confidence intervals (CI)), comparing GET with control interventions. RESULTS: The 10 trials involved 1279 participants. CGI scores of 6 or 7 were reported by 14/333 (4%) participants after GET and 26/334 (8%) participants after control interventions (RR (CI): 0.62 (0.32, 1.17)). Withdrawals from treatment occurred in 64/535 (12%) participants after GET and 53/534 (10%) participants after control interventions (RR (CI):1.21 (0.86, 1.69)). Drop-outs from trial follow up occurred in 74/679 (11%) participants after GET and 41/600 (7%) participants after control interventions (RR (CI): 1.51 (1.03, 2.22)). The certainty of this evidence was rated low by GRADE, due to imprecision. CONCLUSIONS: There was no evidence of excess harm with graded exercise therapy by either self-rated deterioration or by withdrawing from GET, in comparison to control interventions. More GET participants dropped out of trial follow up in comparison to control interventions. Future research should ascertain the most effective and safest form of graded exercise therapy.

Patterns of daytime physical activity in patients with chronic fatigue syndrome.

OBJECTIVES: To classify patients with chronic fatigue syndrome (CFS) by pattern of physical activity and determine the clinical associations of each type. METHODS: 579 out of 641 participants with CFS from the PACE (Pacing, graded Activity, Cognitive behavioural therapy: a randomised Evaluation) trial wore an Actiwatch (accelerometer) for between 3 and 7 days before any trial treatments, which provided a measure of physical activity. Participants' activity was categorised into one of four patterns (pervasively inactive, pervasively active, boom and bust, or indeterminate) primarily using a priori definitions of activity. Clinical associations were sought with each group using an exploratory logistic regression with the indeterminate activity group being the reference group. RESULTS: 124 (21%) of the participants were classified as pervasively inactive, 65 (11%) as pervasively active, 172 (30%) showed a 'boom and bust' pattern of activity, and 218 (38%) had an indeterminate pattern. Pervasively inactive patients were more physically disabled, those in the pervasively active group were more anxious, and those in the boom and bust group had more sleep disturbance. CONCLUSION: We were able to classify patients with CFS into groups by their daytime activity pattern. The different patterns of activity were associated with important clinical variables, suggesting that they might be helpful in determining prognosis and targeting treatments. These associations need replication.

Measurement error, time lag, unmeasured confounding: Considerations for longitudinal estimation of the effect of a mediator in randomised clinical trials.

Clinical trials are expensive and time-consuming and so should also be used to study how treatments work, allowing for the evaluation of theoretical treatment models and refinement and improvement of treatments. These treatment processes can be studied using mediation analysis. Randomised treatment makes some of the assumptions of mediation models plausible, but the mediator-outcome relationship could remain subject to bias. In addition, mediation is assumed to be a temporally ordered longitudinal process, but estimation in most mediation studies to date has been cross-sectional and unable to explore this assumption. This study used longitudinal structural equation modelling of mediator and outcome measurements from the PACE trial of rehabilitative treatments for chronic fatigue syndrome (ISRCTN 54285094) to address these issues. In particular, autoregressive and simplex models were used to study measurement error in the mediator, different time lags in the mediator-outcome relationship, unmeasured confounding of the mediator and outcome, and the assumption of a constant mediator-outcome relationship over time. Results showed that allowing for measurement error and unmeasured confounding were important. Contemporaneous rather than lagged mediator-outcome effects were more consistent with the data, possibly due to the wide spacing of measurements. Assuming a constant mediator-outcome relationship over time increased precision.

Cytokine responses to exercise and activity in patients with chronic fatigue syndrome: case-control study.

Chronic fatigue syndrome (CFS) is characterized by fatigue after exertion. A systematic review suggested that transforming growth factor (TGF)-ß concentrations are often elevated in cases of CFS when compared to healthy controls. This study attempted to replicate this finding and investigate whether post-exertional symptoms were associated with altered cytokine protein concentrations and their RNA in CFS patients. Twenty-four patients fulfilling Centers for Disease Control criteria for CFS, but with no comorbid psychiatric disorders, were recruited from two CFS clinics in London, UK. Twenty-one healthy, sedentary controls were matched by gender, age and other variables. Circulating proteins and RNA were measured for TGF-ß, tumour necrosis factor (TNF), interleukin (IL)-8, IL-6 and IL-1ß. We measured six further cytokine protein concentrations (IL-2, IL-4, IL-5, IL-10, IL-12p70, and interferon (IFN)-γ). Measures were taken at rest, and before and after both commuting and aerobic exercise. CFS cases had higher TGF-ß protein levels compared to controls at rest (median (quartiles) = 43·9 (19·2, 61·8) versus 18·9 (16·1, 30·0) ng/ml) (P = 0·003), and consistently so over a 9-day period. However, this was a spurious finding due to variation between different assay batches. There were no differences between groups in changes to TGF-ß protein concentrations after either commuting or exercise. All other cytokine protein and RNA levels were similar between cases and controls. Post-exertional symptoms and perceived effort were not associated with any increased cytokines. We were unable to replicate previously found elevations in circulating cytokine concentrations, suggesting that elevated circulating cytokines are not important in the pathophysiology of CFS.

A survey to determine usual care after cancer treatment within the United Kingdom national health service.

BACKGROUND: Approximately one third of cancer survivors in the United Kingdom face ongoing and debilitating psychological and physical symptoms related to poor quality of life. Very little is known about current post-cancer treatment services. METHODS: Oncology healthcare professionals (HCPs) were invited to take part in a survey, which gathered both quantitative and free text data about the content and delivery of cancer aftercare and patient needs. Analysis involved descriptive statistics and content analysis. RESULTS: There were 163 complete responses from 278 survey participants; 70% of NHS acute trusts provided data. HCPs views on patient post-cancer treatment needs were most frequently: fear of recurrence (95%), fatigue (94%), changes in physical capabilities (89%), anxiety (89%) and depression (88%). A median number of 2 aftercare sessions were provided (interquartile range: 1,4) lasting between 30 and 60 min. Usually these were provided face-to-face and intermittently by a HCP. However, sessions did not necessarily address the issues HCPs asserted as important. Themes from free-text responses highlighted inconsistencies in care, uncertain funding for services and omission of some evidence based approaches. CONCLUSION: Provision of post-cancer treatment follow-up care is neither universal nor consistent in the NHS, nor does it address needs HCPs identified as most important.

Heterogeneity in chronic fatigue syndrome - empirically defined subgroups from the PACE trial.

BACKGROUND: Chronic fatigue syndrome is likely to be a heterogeneous condition. Previous studies have empirically defined subgroups using combinations of clinical and biological variables. We aimed to explore the heterogeneity of chronic fatigue syndrome. METHOD: We used baseline data from the PACE trial, which included 640 participants with chronic fatigue syndrome. Variable reduction, using a combination of clinical knowledge and principal component analyses, produced a final dataset of 26 variables for 541 patients. Latent class analysis was then used to empirically define subgroups. RESULTS: The most statistically significant and clinically recognizable model comprised five subgroups. The largest, 'core' subgroup (33% of participants), had relatively low scores across all domains and good self-efficacy. A further three subgroups were defined by: the presence of mood disorders (21%); the presence of features of other functional somatic syndromes (such as fibromyalgia or irritable bowel syndrome) (21%); or by many symptoms - a group which combined features of both of the above (14%). The smallest 'avoidant-inactive' subgroup was characterized by physical inactivity, belief that symptoms were entirely physical in nature, and fear that they indicated harm (11%). Differences in the severity of fatigue and disability provided some discriminative validation of the subgroups. CONCLUSIONS: In addition to providing further evidence for the heterogeneity of chronic fatigue syndrome, the subgroups identified may aid future research into the important aetiological factors of specific subtypes of chronic fatigue syndrome and the development of more personalized treatment approaches.

Complementary and alternative healthcare use by participants in the PACE trial of treatments for chronic fatigue syndrome.

BACKGROUND: Chronic Fatigue Syndrome (CFS) is characterised by persistent fatigue, disability and a range of other symptoms. The PACE trial was randomised to compare four non-pharmacological treatments for patients with CFS in secondary care clinics. The aims of this sub study were to describe the use of complementary and alternative medicine (CAM) in the trial sample and to test whether CAM use correlated with an improved outcome. METHOD: CAM use was recorded at baseline and 52weeks. Logistic and multiple regression models explored relationships between CAM use and both patient characteristics and trial outcomes. RESULTS: At baseline, 450/640 (70%) of participants used any sort of CAM; 199/640 (31%) participants were seeing a CAM practitioner and 410/640 (64%) were taking a CAM medication. At 52weeks, those using any CAM fell to 379/589 (64%). Independent predictors of CAM use at baseline were female gender, local ME group membership, prior duration of CFS and treatment preference. At 52weeks, the associated variables were being female, local ME group membership, and not being randomised to the preferred trial arm. There were no significant associations between any CAM use and fatigue at either baseline or 52weeks. CAM use at baseline was associated with a mean (CI) difference of 4.10 (1.28, 6.91; p=0.024) increased SF36 physical function score at 52weeks, which did not reach the threshold for a clinically important difference. CONCLUSION: CAM use is common in patients with CFS. It was not associated with any clinically important trial outcomes.

Chronic fatigue syndrome and circulating cytokines: A systematic review.

There has been much interest in the role of the immune system in the pathophysiology of chronic fatigue syndrome (CFS), as CFS may develop following an infection and cytokines are known to induce acute sickness behaviour, with similar symptoms to CFS. Using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) guidelines, a search was conducted on PubMed, Web of Science, Embase and PsycINFO, for CFS related-terms in combination with cytokine-related terms. Cases had to meet established criteria for CFS and be compared with healthy controls. Papers retrieved were assessed for both inclusionary criteria and quality. 38 papers met the inclusionary criteria. The quality of the studies varied. 77 serum or plasma cytokines were measured without immune stimulation. Cases of CFS had significantly elevated concentrations of transforming growth factor-beta (TGF-ß) in five out of eight (63%) studies. No other cytokines were present in abnormal concentrations in the majority of studies, although insufficient data were available for some cytokines. Following physical exercise there were no differences in circulating cytokine levels between cases and controls and exercise made no difference to already elevated TGF-ß concentrations. The finding of elevated TGF-ß concentration, at biologically relevant levels, needs further exploration, but circulating cytokines do not seem to explain the core characteristic of post-exertional fatigue.

Pain in chronic fatigue syndrome: response to rehabilitative treatments in the PACE trial.

BACKGROUND: Pain is a common symptom of chronic fatigue syndrome (CFS). We investigated the effects of the treatments used in the PACE trial [cognitive behavioural therapy (CBT), graded exercise therapy (GET), adaptive pacing therapy (APT) and specialist medical care (SMC)] on pain in CFS. METHOD: We compared pain outcomes including individual painful symptoms, taken from the CDC criteria for CFS and co-morbid fibromyalgia. We modelled outcomes adjusting for baseline variables with multiple linear regression. RESULTS: Significantly less frequent muscle pain was reported by patients following treatment with CBT compared to SMC (mean difference = 0.38 unit change in frequency, p = 0.02), GET versus SMC (0.42, p = 0.01) and GET versus APT (0.37, p = 0.01). Significantly less joint pain was reported following CBT versus APT (0.35, p = 0.02) and GET versus APT (0.36, p = 0.02). Co-morbid fibromyalgia was less frequent following GET versus SMC (0.03, p = 0.03). The effect sizes of these differences varied between 0.25 and 0.31 for muscle pain and 0.24 and 0.26 for joint pain. Treatment effects on pain were independent of 'change in fatigue'. CONCLUSIONS: CBT and GET were more effective in reducing the frequency of both muscle and joint pain than APT and SMC. When compared to SMC, GET also reduced the frequency of co-morbid fibromyalgia; the size of this effect on pain was small.

Treatment outcome in adults with chronic fatigue syndrome: a prospective study in England based on the CFS/ME National Outcomes Database.

BACKGROUND: Chronic fatigue syndrome (CFS) is relatively common and disabling. Over 8000 patients attend adult services each year, yet little is known about the outcome of patients attending NHS services. AIM: Investigate the outcome of patients with CFS and what factors predict outcome. DESIGN: Longitudinal patient cohort. METHODS: We used data from six CFS/ME (myalgic encephalomyelitis) specialist services to measure changes in fatigue (Chalder Fatigue Scale), physical function (SF-36), anxiety and depression (Hospital Anxiety and Depression Scale) and pain (visual analogue pain rating scale) between clinical assessment and 8-20 months of follow-up. We used multivariable linear regression to investigate baseline factors associated with outcomes at follow-up. RESULTS: Baseline data obtained at clinical assessment were available for 1643 patients, of whom 834 (51%) had complete follow-up data. There were improvements in fatigue [mean difference from assessment to outcome: -6.8; 95% confidence interval (CI) -7.4 to -6.2; P < 0.001]; physical function (4.4; 95% CI 3.0-5.8; P < 0.001), anxiety (-0.6; 95% CI -0.9 to -0.3; P < 0.001), depression (-1.6; 95% CI -1.9 to -1.4; P < 0.001) and pain (-5.3; 95% CI -7.0 to -3.6; P < 0.001). Worse fatigue, physical function and pain at clinical assessment predicted a worse outcome for fatigue at follow-up. Older age, increased pain and physical function at assessment were associated with poorer physical function at follow-up. CONCLUSION: Patients who attend NHS specialist CFS/ME services can expect similar improvements in fatigue, anxiety and depression to participants receiving cognitive behavioural therapy and graded exercise therapy in a recent trial, but are likely to experience less improvement in physical function. Outcomes were predicted by fatigue, disability and pain at assessment.

Recovery from chronic fatigue syndrome after treatments given in the PACE trial.

BACKGROUND: A multi-centre, four-arm trial (the PACE trial) found that rehabilitative cognitive behaviour therapy (CBT) and graded exercise therapy (GET) were more effective treatments for chronic fatigue syndrome (CFS) than specialist medical care (SMC) alone, when each was added to SMC, and more effective than adaptive pacing therapy (APT) when added to SMC. In this study we compared how many participants recovered after each treatment. METHOD: We defined recovery operationally using multiple criteria, and compared the proportions of participants meeting each individual criterion along with two composite criteria, defined as (a) recovery in the context of the trial and (b) clinical recovery from the current episode of the illness, however defined, 52 weeks after randomization. We used logistic regression modelling to compare treatments. RESULTS: The percentages (number/total) meeting trial criteria for recovery were 22% (32/143) after CBT, 22% (32/143) after GET, 8% (12/149) after APT and 7% (11/150) after SMC. Similar proportions met criteria for clinical recovery. The odds ratio (OR) for trial recovery after CBT was 3.36 [95% confidence interval (CI) 1.64­6.88] and for GET 3.38 (95% CI 1.65­6.93), when compared to APT, and after CBT 3.69 (95% CI 1.77­7.69) and GET 3.71 (95% CI 1.78­7.74), when compared to SMC (p values < or =0.001 for all comparisons). There was no significant difference between APT and SMC. Similar proportions recovered in trial subgroups meeting different definitions of the illness. CONCLUSIONS: This study confirms that recovery from CFS is possible, and that CBT and GET are the therapies most likely to lead to recovery.

Cognitions, behaviours and co-morbid psychiatric diagnoses in patients with chronic fatigue syndrome.

BACKGROUND: Specific cognitions and behaviours are hypothesized to be important in maintaining chronic fatigue syndrome (CFS). Previous research has shown that a substantial proportion of CFS patients have co-morbid anxiety and/or depression. This study aims to measure the prevalence of specific cognitions and behaviours in patients with CFS and to determine their association with co-morbid anxiety or depression disorders. METHOD: A total of 640 patients meeting Oxford criteria for CFS were recruited into a treatment trial (i.e. the PACE trial). Measures analysed were: the Cognitive Behavioural Response Questionnaire, the Chalder Fatigue Scale and the Work and Social Adjustment Scale. Anxiety and depression diagnoses were from the Structured Clinical Interview for DSM-IV. Multivariate analysis of variance was used to explore the associations between cognitive-behavioural factors in patients with and without co-morbid anxiety and/or depression. RESULTS: Of the total sample, 54% had a diagnosis of CFS and no depression or anxiety disorder, 14% had CFS and one anxiety disorder, 14% had CFS and depressive disorder and 18% had CFS and both depression and anxiety disorders. Cognitive and behavioural factors were associated with co-morbid diagnoses; however, some of the mean differences between groups were small. Beliefs about damage and symptom focussing were more frequent in patients with anxiety disorders while embarrassment and behavioural avoidance were more common in patients with depressive disorder. CONCLUSIONS: Cognitions and behaviours hypothesized to perpetuate CFS differed in patients with concomitant depression and anxiety. Cognitive behavioural treatments should be tailored appropriately.

Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial.

BACKGROUND: Trial findings show cognitive behaviour therapy (CBT) and graded exercise therapy (GET) can be effective treatments for chronic fatigue syndrome, but patients' organisations have reported that these treatments can be harmful and favour pacing and specialist health care. We aimed to assess effectiveness and safety of all four treatments. METHODS: In our parallel-group randomised trial, patients meeting Oxford criteria for chronic fatigue syndrome were recruited from six secondary-care clinics in the UK and randomly allocated by computer-generated sequence to receive specialist medical care (SMC) alone or with adaptive pacing therapy (APT), CBT, or GET. Primary outcomes were fatigue (measured by Chalder fatigue questionnaire score) and physical function (measured by short form-36 subscale score) up to 52 weeks after randomisation, and safety was assessed primarily by recording all serious adverse events, including serious adverse reactions to trial treatments. Primary outcomes were rated by participants, who were necessarily unmasked to treatment assignment; the statistician was masked to treatment assignment for the analysis of primary outcomes. We used longitudinal regression models to compare SMC alone with other treatments, APT with CBT, and APT with GET. The final analysis included all participants for whom we had data for primary outcomes. This trial is registered at http://isrctn.org, number ISRCTN54285094. FINDINGS: We recruited 641 eligible patients, of whom 160 were assigned to the APT group, 161 to the CBT group, 160 to the GET group, and 160 to the SMC-alone group. Compared with SMC alone, mean fatigue scores at 52 weeks were 3·4 (95% CI 1·8 to 5·0) points lower for CBT (p = 0·0001) and 3·2 (1·7 to 4·8) points lower for GET (p = 0·0003), but did not differ for APT (0·7 [-0·9 to 2·3] points lower; p = 0·38). Compared with SMC alone, mean physical function scores were 7·1 (2·0 to 12·1) points higher for CBT (p = 0·0068) and 9·4 (4·4 to 14·4) points higher for GET (p = 0·0005), but did not differ for APT (3·4 [-1·6 to 8·4] points lower; p=0·18). Compared with APT, CBT and GET were associated with less fatigue (CBT p = 0·0027; GET p = 0·0059) and better physical function (CBT p=0·0002; GET p<0·0001). Subgroup analysis of 427 participants meeting international criteria for chronic fatigue syndrome and 329 participants meeting London criteria for myalgic encephalomyelitis yielded equivalent results. Serious adverse reactions were recorded in two (1%) of 159 participants in the APT group, three (2%) of 161 in the CBT group, two (1%) of 160 in the GET group, and two (1%) of 160 in the SMC-alone group. INTERPRETATION: CBT and GET can safely be added to SMC to moderately improve outcomes for chronic fatigue syndrome, but APT is not an effective addition. FUNDING: UK Medical Research Council, Department of Health for England, Scottish Chief Scientist Office, Department for Work and Pensions.