Does the effect of cognitive behavior therapy for chronic fatigue syndrome (ME/CFS) vary by patient characteristics? A systematic review and individual patient data meta-analysis.

Debate is ongoing on the efficacy of cognitive behavior therapy (CBT) for myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS). With an individual patient data (IPD) meta-analysis we investigated whether the effect of CBT varied by patient characteristics. These included post-exertional malaise (PEM), a central feature of ME/CFS according to many. We searched for randomized controlled trials similar with respect to comparison condition, outcomes and treatment-protocol. Moderation on fatigue severity (Checklist Individual Strength, subscale fatigue severity), functional impairment (Sickness Impact Profile-8) and physical functioning (Short Form-36, subscale physical functioning) was investigated using linear mixed model analyses and interaction tests. PROSPERO (CRD42022358245). Data from eight trials (n = 1298 patients) were pooled. CBT showed beneficial effects on fatigue severity (ß = -11.46, 95% CI -15.13 to -7.79); p < 0.001, functional impairment (ß = -448.40, 95% CI -625.58 to -271.23); p < 0.001; and physical functioning (ß = 9.64, 95% CI 3.30 to 15.98); p < 0.001. The effect of CBT on fatigue severity varied by age (pinteraction = 0.003), functional impairment (pinteraction = 0.045) and physical activity pattern (pinteraction = 0.027). Patients who were younger, reported less functional impairments and had a fluctuating activity pattern benefitted more. The effect on physical functioning varied by self-efficacy (pinteraction = 0.025), with patients with higher self-efficacy benefitting most. No other moderators were found. It can be concluded from this study that CBT for ME/CFS can lead to significant reductions of fatigue, functional impairment, and physical limitations. There is no indication patients meeting different case definitions or reporting additional symptoms benefit less from CBT. Our findings do not support recent guidelines in which evidence from studies not mandating PEM was downgraded.

Cognitive behavioral therapy or graded exercise therapy compared with usual care for severe fatigue in patients with advanced cancer during treatment: a randomized controlled trial.

BACKGROUND: Cancer-related fatigue remains a prevalent and burdensome symptom experienced by patients with advanced cancer. Our aim was to assess the effects of cognitive behavioral therapy (CBT) or graded exercise therapy (GET) on fatigue in patients with advanced cancer during treatment with palliative intent. PATIENTS AND METHODS: A randomized controlled trial was conducted from 1 January 2013 to 1 September 2017. Adult patients with locally advanced or metastatic cancer who reported severe fatigue during treatment [Checklist Individual Strength, subscale fatigue severity (CIS-fatigue) ≥35] were accrued across nine centers in The Netherlands. Patients were randomly assigned to either 12 weeks of CBT or GET, or usual care (1 : 1: 1, computer-generated sequence). Primary outcome was CIS-fatigue at 14 weeks. Secondary outcomes included fatigue measured with the European Organisation for Research and Treatment of Cancer-Quality of Life Questionnaire (EORTC-QLQ-C30), quality of life, emotional functioning, physical functioning, and functional impairments at baseline, 14, 18, and 26 weeks. RESULTS: Among 134 participants randomized, the mean age was 63 (standard deviation 9) years and 77 (57%) were women. Common diagnoses included: breast (41%), colorectal (28%), and prostate cancer (17%). A total of 126 participants completed assessment at 14 weeks. Compared with usual care, CBT significantly reduced fatigue [difference -7.2, 97.5% confidence interval (CI) -12.7 to -1.7; P = 0.003, d = 0.7], whereas GET did not (-4.7, 97.5% CI -10.2 to 0.9; P = 0.057, d = 0.4). CBT significantly reduced EORTC-QLQ-C30 fatigue (-13.1, 95% CI -22.1 to -4.0; P = 0.005) and improved quality of life (10.2, 95% CI 2.4 to 17.9; P = 0.011) and physical functioning (7.1, 95% CI 0.5 to 13.7; P = 0.036) compared with usual care. Improvement in emotional functioning and decrease in functional impairments failed to reach significance. GET did not improve secondary outcomes compared with usual care. CONCLUSIONS: Among advanced cancer patients with severe fatigue during treatment, a CBT intervention was more effective than usual care for reducing fatigue. Following GET, patients reported lower fatigue, but results were not significant, probably due to a smaller sample size and lower adherence than anticipated. TRIAL REGISTRATION: Netherlands National Trial Register, identifier: NTR3812.

Graded activity is an important component in cognitive behavioral therapy to reduce severe fatigue: results of a pragmatic crossover trial in cancer survivors.

Background: Fatigue is one of the most common and distressing long-term effects of cancer treatment. Cognitive behavioral therapy (CBT) is an evidence-based intervention for patients with severe post-cancer fatigue. CBT for fatigue is a complex intervention consisting of multiple elements like a graded activity program, regulation of the sleep-wake rhythm and reformulation of fatigue-related cognitions. The contribution of the separate elements to the positive effect of CBT on fatigue is unclear. The main objective of this pragmatic crossover trial was comparing the efficacy of graded activity with the other elements of CBT in reducing post-cancer fatigue.Material and methods: Severely fatigued cancer survivors were randomized to (i) graded activity followed by the other elements of CBT after crossover (n = 41), or (ii) the two components in reverse order (n = 48). Fatigue severity was measured at baseline, before crossover and after CBT (Checklist Individual Strength (CIS), Fatigue Severity subscale). Differences in effects on fatigue were examined with a linear regression analysis. Objective physical activity, perceived activity and self-efficacy were explored as mediators of the effect of graded activity.Results: Before crossover, the reduction in fatigue was significantly larger after graded activity than after the other elements (ß = 4.75, 95% confidence interval (95% CI) = -9.19; -0.32). An increase in perceived activity mediated this effect (ß = -4.17, 95% CI = -7.37; -1.37).Conclusions: Graded activity is an important component of CBT for post-cancer fatigue as it resulted in a larger reduction in fatigue compared with the other elements, mediated by an increased level of perceived activity. Results indicated that the other elements of CBT are of added value in reducing fatigue.

Efficacy of web-based cognitive-behavioural therapy for chronic fatigue syndrome: randomised controlled trial.

BACKGROUND: Face-to-face cognitive-behavioural therapy (CBT) leads to a reduction of fatigue in chronic fatigue syndrome (CFS). Aims To test the efficacy of internet-based CBT (iCBT) for adults with CFS. METHOD: A total of 240 patients with CFS were randomised to either iCBT with protocol-driven therapist feedback or with therapist feedback on demand, or a waiting list. Primary outcome was fatigue severity assessed with the Checklist Individual Strength (Netherlands Trial Register: NTR4013). RESULTS: Compared with a waiting list, intention-to-treat (ITT) analysis showed a significant reduction of fatigue for both iCBT conditions (protocol-driven feedback: B = -8.3, 97.5% CI -12.7 to -3.9, P < 0.0001; feedback on demand: B = -7.2, 97.5% CI -11.3 to -3.1, P < 0.0001). No significant differences were found between both iCBT conditions on all outcome measures (P = 0.3-0.9). An exploratory analysis revealed that feedback-on-demand iCBT required less therapist time (mean 4 h 37 min) than iCBT with protocol-driven feedback (mean 6 h 9 min, P < 0.001) and also less than face-to-face CBT as reported in the literature. CONCLUSIONS: Both iCBT conditions are efficacious and time efficient. Declaration of interest None.

Cognitive behavioural therapy for MS-related fatigue explained: A longitudinal mediation analysis.

BACKGROUND: Cognitive behavioural therapy (CBT) effectively reduces fatigue directly following treatment in patients with Multiple Sclerosis (MS), but little is known about the process of change during and after CBT. DESIGN: Additional analysis of a randomized clinical trial. OBJECTIVE: To investigate which psychological factors mediate change in fatigue during and after CBT. METHODS: TREFAMS-CBT studied the effectiveness of a 16-week CBT treatment for MS-related fatigue. Ninety-one patients were randomized (44 to CBT, 47 to the MS-nurse consultations). Mediation during CBT treatment was studied using assessments at baseline, 8 and 16weeks. Mediation of the change in fatigue from post-treatment to follow-up was studied separately using assessments at 16, 26 and 52weeks. Proposed mediators were: changes in illness cognitions, general self-efficacy, coping styles, daytime sleepiness, concentration and physical activity, fear of disease progression, fatigue perceptions, depression and physical functioning. Mediators were separately analysed according to the product-of-coefficients approach. Confidence intervals were calculated with a bootstrap procedure. RESULTS: During treatment the decrease in fatigue brought on by CBT was mediated by improved fatigue perceptions, increased physical activity, less sleepiness, less helplessness, and improved physical functioning. Post-treatment increases in fatigue levels were mediated by reduced physical activity, reduced concentration, and increased sleepiness. CONCLUSION: These results suggests that focusing on improving fatigue perceptions, perceived physical activity, daytime sleepiness, helplessness, and physical functioning may further improve the effectiveness of CBT for fatigue in patients with MS. Maintenance of treatment effects may be obtained by focusing on improving physical activity, concentration and sleepiness.

The assessment of fatigue: Psychometric qualities and norms for the Checklist individual strength.

OBJECTIVE: The Checklist Individual Strength (CIS) measures four dimensions of fatigue: Fatigue severity, concentration problems, reduced motivation and activity. On the fatigue severity subscale, a cut-off score of 35 is used. This study 1) investigated the psychometric qualities of the CIS; 2) validated the cut-off score for severe fatigue and 3) provided norms. METHODS: Representatives of the Dutch general population (n=2288) completed the CIS. The factor structure was investigated using an exploratory factor analysis. Internal consistency and test-retest reliability were determined. Concurrent validity was assessed in two additional samples by correlating the CIS with other fatigue scales (Chalder Fatigue Questionnaire, MOS Short form-36 Vitality subscale, EORTC QLQ-C30 fatigue subscale). To validate the fatigue severity cut-off score, a Receiver Operating Characteristics analysis was performed with patients referred to a chronic fatigue treatment centre (n=5243) and a healthy group (n=1906). Norm scores for CIS subscales were calculated for the general population, patients with chronic fatigue syndrome (CFS; n=1407) and eight groups with other medical conditions (n=1411). RESULTS: The original four-factor structure of the CIS was replicated. Internal consistency (α=0.84-0.95) and test-retest reliability (r=0.74-0.86) of the subscales were high. Correlations with other fatigue scales were moderate to high. The 35 points cut-off score for severe fatigue is appropriate, but, given the 17% false positive rate, should be adjusted to 40 for research in CFS. CONCLUSION: The CIS is a valid and reliable tool for the assessment of fatigue, with a validated cut-off score for severe fatigue that can be used in clinical practice.

The efficacy of guided self-instruction for patients with idiopathic chronic fatigue: A randomized controlled trial.

OBJECTIVE: To determine the efficacy of a cognitive-behavioral intervention for patients meeting U.S. Centers for Disease Control and Prevention (CDC) criteria for idiopathic chronic fatigue (ICF). ICF is thought to be a less severe disorder than chronic fatigue syndrome (CFS). The intervention consisted of a booklet with self-instructions combined with e-mail contact with a therapist. METHOD: Randomized controlled trial conducted at an outpatient facility. All patients suffered from severe and persistent fatigue with moderate impairment levels or fewer than 4 additional symptoms. Patients were randomly allocated to either guided self-instruction or a wait-list control group. Primary outcome measures were fatigue severity assessed with the Checklist Individual Strength and level of overall impairment assessed with the Sickness Impact Profile. Outcome measures were assessed prior to randomization and following treatment or wait-list control group. RESULTS: One hundred patients were randomly allocated to the intervention or a wait-list control group and 95 completed second assessment. An intention-to-treat analysis showed significant treatment effects for fatigue severity (-8.98, 95% confidence interval [CI] [-13.99, -3.97], Cohen's d = 0.68, p < .001) and for overall impairment (-317.19, 95% CI [-481.70, -152.68], Cohen's d = 0.53, p < .01) in favor of the intervention. The number of additional symptoms and overall impairment at baseline did not moderate posttreatment fatigue severity. Baseline overall impairment moderated posttreatment impairment. CONCLUSIONS: Patients with ICF can be treated effectively with a minimal intervention. This is relevant as ICF is more prevalent than CFS and treatment capacity is limited.

The role of the partner and relationship satisfaction on treatment outcome in patients with chronic fatigue syndrome.

BACKGROUND: Cognitive behaviour therapy (CBT) for chronic fatigue syndrome (CFS) leads to a significant decrease in CFS-related symptoms and disability. The primary objective of this study was to explore whether partners' solicitous responses and patients' and partners' perceived relationship satisfaction had an effect on treatment outcome. METHOD: The treatment outcome of a cohort of 204 consecutively referred patients treated with CBT was analysed. At baseline, CFS patients completed the Maudsley Marital Questionnaire. The Checklist Individual Strength subscale Fatigue and the Sickness Impact Profile total scores completed by CFS patients post-treatment were used as measures of clinically significant improvement. Partners completed the Family Response Questionnaire, the Maudsley Marital Questionnaire, the Brief Illness Perception Questionnaire, and the Causal Attribution List. Logistic regression analyses were performed with clinically significant improvement in fatigue and disability as dependent variables and scores on questionnaires at baseline as predictors. RESULTS: Solicitous responses of the partner were associated with less clinically significant improvement in fatigue and disability. Partners more often reported solicitous responses when they perceived CFS as a severe condition. Patients' relationship dissatisfaction was negatively associated with clinically significant improvement in fatigue. CONCLUSIONS: Partners' solicitous responses and illness perceptions at the start of the therapy can negatively affect the outcome of CBT for CFS. We emphasize the importance of addressing this in therapy.

Effect of Aerobic Exercise Training on Fatigue in Rheumatoid Arthritis: A Meta-Analysis.

OBJECTIVE: Rheumatoid arthritis (RA) fatigue is not being well-managed currently, and evidence of effective interventions is limited. Aerobic exercise may provide benefit to treat fatigue in RA. Therefore, the purpose of this meta-analysis is to analyze the effect of aerobic land-based exercise on fatigue in RA. METHODS: A literature search was conducted using PubMed, Cochrane Library, Embase, and trial registers to identify randomized controlled trials (RCTs) with a supervised land-based aerobic exercise program performed with an intensity between 50% and 90% of maximal heart rate, of at least 15 minutes' duration, performed at least 2 times a week, and lasting for a time period of at least 4 consecutive weeks. Risk of bias was assessed using the Cochrane tool. A meta-analysis of fatigue outcomes was performed by calculating the standardized mean difference (SMD) using a random-effects model. RESULTS: Five RCTs were included. None of the trials selected patients with RA for having fatigue. Risk of bias was low in 3 RCTs and unclear in 2. Land-based aerobic exercise programs had a positive effect on fatigue in RA compared to no exercise at 12 weeks, SMD -0.31 (95% confidence interval [95% CI] -0.55, -0.06). At 24 weeks, the effect of aerobic land-based exercise was smaller and not statistically significant: SMD -0.15 (95% CI -0.33, 0.02). CONCLUSION: There is evidence with low risk of bias that an aerobic exercise program is effective in reducing fatigue among patients with RA, especially in the short term; however, effects are small. To substantiate the evidence, RCTs should be performed in patients with RA selected for having fatigue.

Severe fatigue in patients with adrenal insufficiency: physical, psychosocial and endocrine determinants.

BACKGROUND: Fatigue is a frequently experienced complaint in patients with adrenal insufficiency (AI) and may be influenced by cortisol levels. AIM: The objective of this study was to determine the prevalence of severe fatigue in adrenal insufficiency (AI) patients, to assess which dimensions contribute to fatigue severity and to determine the association between salivary cortisol levels and momentary fatigue. SUBJECTS AND METHODS: We performed a cross-sectional study in the outpatient department of a university hospital. Included were 27 patients with congenital adrenal hyperplasia (CAH), 26 patients with primary AI (PAI), 24 patients with secondary AI (SAI) and 31 patients with adrenal insufficiency after treatment for Cushing's syndrome (Cush-AI). Measurements included computerised questionnaires to determine fatigue severity and physical and psychosocial contributors. Patients took four saliva samples at home, in which cortisol levels were measured. RESULTS: Severe fatigue was experienced by 41 % of the CAH patients, 42 % of the PAI patients, 50 % of the SAI patients and 42 % of the Cush-AI patients. Psychological distress, functional impairment, sleep disturbance, physical activity, concentration problems and social functioning contributed to the subjective experience of fatigue. Salivary cortisol levels were not correlated with momentary fatigue. CONCLUSIONS: A considerable proportion of AI patients experience severe fatigue. Salivary cortisol level is not a significant predictor for momentary fatigue in AI patients.

Relationship between objectively assessed physical activity and fatigue in patients with rheumatoid arthritis: inverse correlation of activity and fatigue.

OBJECTIVE: Fatigue is generally associated with low physical activity in patients with various chronic medical conditions. However, such an association has not been reported among patients with rheumatoid arthritis (RA). The objectives of this study were to investigate whether daily activity level is associated with fatigue in patients with RA, and whether pain, disability, coping, and/or cognition are associated with the level of daily activity. METHODS: Patients with RA who visited our outpatient clinic were recruited consecutively. Fatigue severity was measured using the Checklist Individual Strength (CIS20). Physical activity was measured for 14 consecutive days using an ankle-worn actometer. The daily activity level of each patient was calculated, and each patient was classified as having a low or high activity level with respect to the group average. Data were analyzed by linear regression. RESULTS: A total of 167 patients were included in the analysis; 25% had a low activity level and 75% had a high activity level. A regression analysis revealed that higher activity levels were associated with reduced fatigue (P = 0.008). The mean ± SD CIS fatigue score was 30.9 ± 12.3 among the patients with a high activity level and 35.7 ± 12.8 among the patients with a low activity level (P = 0.03). Pain, disability, coping, and cognition were not associated significantly with daily activity level. CONCLUSION: Among patients with RA, a higher level of daily physical activity was associated with reduced levels of fatigue. This relationship was not explained by differences in sex, age, disease duration, pain, disability, or other fatigue-related factors.

Association between fatigue and pain in rheumatoid arthritis: does pain precede fatigue or does fatigue precede pain?

OBJECTIVE: Fatigue and pain are important symptoms for patients with rheumatoid arthritis (RA), but their temporal association is unknown. Therefore, the objective of this study was to investigate the longitudinal relationship between fatigue and pain in patients with RA using time-lag models. METHODS: Consecutive RA outpatients (n = 228) were enrolled for this 1-year study. Fatigue was assessed monthly with the Checklist Individual Strength (CIS; range 8-56) and pain was assessed monthly with the bodily pain subscale (inverted, range 0-100) of the Short Form 36. The association between monthly changes in fatigue and pain was analyzed using longitudinal regression (mixed models), using the same months and with a 1-month time lag. RESULTS: A total of 198 patients were included in the analyses. At baseline, the mean ± SD pain score was 35.23 ± 19.82 and the mean ± SD CIS fatigue score was 31.0 ± 12.4. Severe fatigue at baseline (CIS score ≥35) was present in 42% of the patients. The mean ± SD patient-averaged CIS fatigue score over 1 year was 30.9 ± 6.0 and the mean ± SD patient-averaged pain score over 1 year was 36.4 ± 18.3. The longitudinal regression analysis showed a significant positive relationship between fatigue and pain during the same month (ß = 2.04; 95% confidence interval 1.82, 2.27). The models using a time lag showed no significant association between changes in pain and changes in fatigue. CONCLUSION: In established RA, pain and fatigue show monthly fluctuations that are synchronous rather than showing a temporal relationship with a time lag; within this timeframe, the results do not indicate that one precedes the other.

The role of physical activity and physical fitness in postcancer fatigue: a randomized controlled trial.

PURPOSE: Patients suffering from postcancer fatigue have both an inferior physical activity and physical fitness compared to non-fatigued cancer survivors. The aims of this study were (1) to examine the effect of cognitive behavior therapy, an effective treatment for postcancer fatigue, on physical activity and physical fitness and (2) to examine whether the effect of cognitive behavior therapy on postcancer fatigue is mediated by physical activity and/or physical fitness. METHODS: Severely fatigued cancer survivors were randomly assigned to either the intervention (cognitive behavior therapy) or the waiting list condition. After assigning 23 patients in the intervention condition and 14 patients in the waiting list condition, they were assessed both at baseline and 6 months later. Physical activity was assessed via actigraphy and physical fitness was assessed by a maximal exercise test. A nonparametric bootstrap approach was used to test the statistical significance of the mediation effects. RESULTS: A significant increase in physical activity was observed in the intervention group from baseline to follow-up, whereas physical activity did not change from baseline to follow-up in the waiting list group. Physical fitness did not significantly change after cognitive behavior therapy or after 6 months of waiting for therapy. Fatigue decreased more significantly in the intervention group than in the waiting list group. The mediation hypotheses were rejected. CONCLUSIONS: Cognitive behavior therapy effectively reduced postcancer fatigue and increased physical activity but did not change physical fitness. The effect of cognitive behavior therapy on postcancer fatigue is not mediated by a change in physical activity or physical fitness.

The effect of anti-TNF-α vs. DMARDs on fatigue in rheumatoid arthritis patients.

OBJECTIVES: Fatigue is experienced frequently by patients with rheumatoid arthritis (RA). Fatigue may be caused by high levels of pain and disease activity in RA but can remain present while disease activity is moderate to low. It is not clear whether RA patients receiving anti-tumour necrosis factor (TNF) treatment reach lower levels of acute fatigue than RA patients receiving disease-modifying anti-rheumatic drug (DMARD) treatment. The aim of our study was to analyse whether, in patients with RA, the effect of anti-TNF on fatigue is greater than the effect of DMARD treatment. METHOD: Sixty-seven RA patients receiving anti-TNF treatment and 104 RA patients receiving DMARDs were included. All patients were on stable treatment for at least 6 months prior to baseline measurement. Fatigue was measured monthly over 1 year with the fatigue severity subscale of the Checklist Individual Strength (CIS-fatigue). The association between persistent severe fatigue and medication group was analysed using multiple linear regression including confounders. RESULTS: In the anti-TNF group the mean (SD) level of persistent fatigue was significantly higher than in the DMARD group [32.2 (11.4) vs. 28.3 (10.9), p = 0.025] and more patients experienced persistent severe (CIS-fatigue score ≥ 35) fatigue (42% and 27% respectively, p = 0.043). However, when correcting for age, disease activity, haemoglobin, treatment duration, pain, physical disability, and clinical depression, medication type seemed to influence neither the mean level of persistent fatigue (p = 0.251) nor the percentage of patients with persistent severe fatigue (p = 0.745). CONCLUSIONS: When taking into account probable confounders including disease activity, medication type did not influence persistent fatigue in RA patients. It seems that, besides its anti-inflammatory effect, anti-TNF has no complementary effect on persistent fatigue.

Maximal exercise performance in patients with postcancer fatigue.

PURPOSE: The aim of this study is to examine whether physical fitness of severely fatigued and non-fatigued cancer survivors, as measured by maximal exercise performance, is different between both groups and, if so, whether this difference can be explained by differences in physical activity, self-efficacy regarding the exercise test, and/or social support. METHODS: Severely fatigued (n = 20) and sex- and age-matched non-fatigued (n = 20) disease-free cancer survivors, who completed treatment for a malignant, solid tumor at least 1 year earlier, participated in this case-control study. Maximal oxygen consumption was measured during an incremental cycling exercise test. Physical activity was assessed via actigraphy. Self-efficacy regarding the test and social support were assessed via questionnaires to study its relationship with physical fitness. RESULTS: Maximal oxygen consumption was significantly lower in fatigued compared to non-fatigued participants. Actual physical activity, self-efficacy regarding the test, and negative interactions of social support were significantly different between both groups. However, after inclusion of these three variables in linear regression analyses, the difference in physical fitness between fatigued and non-fatigued cancer survivors persisted. CONCLUSIONS: Maximal oxygen consumption, a measure for physical fitness, was reduced in severely fatigued compared to non-fatigued cancer survivors. The inferior maximal exercise performance cannot fully be explained by differences in physical activity, self-efficacy, or social support between both groups. Other currently still unknown factors, such as a disturbance in the cardiopulmonary circuit, may play a role.

Implementing a minimal intervention for chronic fatigue syndrome in a mental health centre: a randomized controlled trial.

BACKGROUND: Cognitive behaviour therapy (CBT) for chronic fatigue syndrome (CFS) is an effective but intensive treatment, requiring trained therapists. A minimal intervention based on CBT for CFS, guided self-instruction, was shown to be an effective treatment when delivered in a tertiary treatment centre. Implementing this intervention in a community-based mental health centre (MHC) will increase the treatment capacity for CFS patients. This study evaluated the effectiveness of guided self-instruction for CFS implemented in an MHC, delivered by nurses. METHOD: One hundred and twenty-three patients were randomly assigned to either guided self-instruction (n=62) or a waiting list (n=61). Randomization was computer generated, with allocation by numbered sealed envelopes. Group allocation was open to all those involved. Patients fulfilled US Centers for Disease Control and Prevention (CDC) criteria for CFS. Primary outcome variables were fatigue severity and physical and social functioning, measured with the Checklist Individual Strength (CIS) and the Medical Outcomes Survey Short Form-36 (SF-36) respectively. RESULTS: After 6 months, patients who followed guided self-instruction reported a significantly larger decrease in fatigue compared to the waiting list [mean difference -8.1, 95% confidence interval (CI) -3.8 to -12.4, controlled effect size 0.70]. There was no significant difference in physical and social functioning. However, post-hoc analyses showed a significant decrease in fatigue and physical disabilities following the intervention in a subgroup of patients with physical disabilities at baseline (SF-36 physical functioning ⩽70). CONCLUSIONS: Implementation of guided self-instruction in a community-based MHC was partially successful. The minimal intervention can be effectively implemented for CFS patients with physical impairments.

Fatigue is associated with muscle weakness in Ehlers-Danlos syndrome: an explorative study.

OBJECTIVES: Ehlers-Danlos syndrome (EDS) is a clinically and genetically heterogeneous group of inherited connective tissue disorders characterised by joint hypermobility, skin hyperextensibility and tissue fragility. It has recently been shown that muscle weakness occurs frequently in EDS, and that fatigue is a common and clinically important symptom. The aim of this study was to investigate the relationship between fatigue severity and subjective and objective measures of muscle weakness. Furthermore, the predictive value of muscle weakness for fatigue severity was determined, together with that of pain and physical activity. DESIGN: An explorative, cross-sectional, observational study. SETTING AND PARTICIPANTS: Thirty EDS patients, recruited from the Dutch patient association, were investigated at the neuromuscular outpatient department of a tertiary referral centre in The Netherlands. MAIN OUTCOME MEASURES: Muscle strength measured with manual muscle strength testing and hand-held dynamometry. Self-reported muscle weakness, pain, physical activity levels and fatigue were assessed with standardised questionnaires. RESULTS: Fatigue severity in EDS was significantly correlated with measured and self-reported muscle weakness (r=-0.408 for manual muscle strength, r=0.461 for hand-held dynamometry and r=0.603 for self-reported muscle weakness). Both muscle weakness and pain severity were significant predictors of fatigue severity in a multiple regression analysis. CONCLUSION: The results suggest a positive and direct relationship between fatigue severity and muscle weakness in EDS. Future research should focus on the relationship between fatigue, muscle weakness and objectively measured physical activity, preferably in a larger cohort of EDS patients.

How does cognitive behaviour therapy reduce fatigue in patients with chronic fatigue syndrome? The role of physical activity.

BACKGROUND: Cognitive behaviour therapy (CBT) is known to reduce fatigue severity in chronic fatigue syndrome (CFS). How this change in symptomatology is accomplished is not yet understood. The purpose of the present study was to determine whether the effect of CBT on fatigue is mediated by an increase in physical activity. METHOD: Three randomized controlled trials were reanalysed, previously conducted to evaluate the efficacy of CBT for CFS. In all samples, actigraphy was used to assess the level of physical activity prior and subsequent to treatment or a control group period. The mediation hypothesis was analysed according to guidelines of Baron & Kenny [Journal of Personality and Social Psychology (1986)51, 1173-1182]. A non-parametric bootstrap approach was used to test statistical significance of the mediation effect. RESULTS: Although CBT effectively reduced fatigue, it did not change the level of physical activity. Furthermore, changes in physical activity were not related to changes in fatigue. Across the samples, the mean mediation effect of physical activity averaged about 1% of the total treatment effect. This effect did not yield significance in any of the samples. CONCLUSIONS: The effect of CBT on fatigue in CFS is not mediated by a persistent increase in physical activity.