The role of partners' fatigue and the patient-partner relationship in the outcome of cognitive behavioural therapy for chronic fatigue syndrome.

BACKGROUND: In chronic fatigue syndrome (CFS) little is known about how partner-related factors influence patients' fatigue symptoms and treatment outcome. We examined partners' fatigue severity, and determined the role of partner-related factors for patients' symptoms and the outcome of cognitive behavioural therapy (CBT). METHODS: 1356 CFS patients and their partners completed baseline measures of fatigue severity (Checklist Individual Strength), causal attributions of symptoms, partner responses to patient symptoms, and relationship satisfaction. Fatigue in partners of patients with CFS was compared with fatigue in age- and gender-matched controls from the Dutch population. Associations between partners' fatigue severity and other partner-related factors were determined. In a subgroup of 760 CFS patients who completed CBT, logistic regression analyses were used to identify partner-related baseline predictors for treatment outcome (fatigue severity, functional impairment). RESULTS: Partners' fatigue (M = 21.66, SD 11.60) was significantly lower than in controls (M = 24.58, SD = 11.02) (p < .001) and not related to patients' fatigue (r = -0.02, p = .58). Partners' fatigue was correlated with patients' functional impairment (p = .001), partners' and patients' relationship dissatisfaction, negative partner responses, and partners' and patients' psychological attributions of patient symptoms at baseline (all p < .001). After controlling for patients' baseline fatigue severity and functional impairment, only relationship dissatisfaction as reported by (female) patients significantly predicted worse treatment outcome. For male patients with female partners, higher partners' fatigue severity predicted higher fatigue severity after CBT. CONCLUSIONS: Female partners' fatigue and relationship dissatisfaction as reported by the female patient should be addressed in CBT for CFS, as these factors affect treatment outcome.

Implementation of stepped care for patients with chronic fatigue syndrome in community-based mental health care: outcomes at post-treatment and long-term follow-up.

BACKGROUND: Cognitive behavioural therapy (CBT) is an evidence-based treatment for chronic fatigue syndrome (CFS). Stepped care for CFS, consisting of a minimal intervention followed by face-to-face CBT, was found efficacious when tested in a CFS specialist centre. Stepped care implemented in a community-based mental health centre (MHC) has not yet been evaluated. AIMS: (1) To test the effectiveness of stepped care for CFS implemented in a MHC at post-treatment and at long-term follow-up; and (2) compare post-treatment outcomes of implemented stepped care with treatment outcomes of a CFS specialist centre. METHOD: An uncontrolled study was used to test effectiveness of stepped care implemented in a MHC (n = 123). The outcomes of implemented care were compared with the outcomes of specialist care reported in previous studies (n = 583). Data on outcomes from implemented stepped care were gathered at post-treatment and at long-term follow-up. Mixed models were used as method of analysis. RESULTS: Fatigue decreased and physical functioning increased significantly following implemented stepped care (both p < .001). The follow-up was completed by 94 patients (78%) within 1-6 years after treatment. Treatment effects were sustained to follow-up. Patients in the MHC showed less improvement directly following stepped care compared with patients in a CFS specialist centre (p < .01). CONCLUSION: Implemented stepped care for CFS is effective with sustained treatment gains at long-term follow-up. There is room for improvement when compared with outcomes of a CFS specialist centre. Some suggestions are made on how to improve stepped care.

Cross-Cultural Study of Information Processing Biases in Chronic Fatigue Syndrome: Comparison of Dutch and UK Chronic Fatigue Patients.

PURPOSE: This study aims to replicate a UK study, with a Dutch sample to explore whether attention and interpretation biases and general attentional control deficits in chronic fatigue syndrome (CFS) are similar across populations and cultures. METHOD: Thirty eight Dutch CFS participants were compared to 52 CFS and 51 healthy participants recruited from the UK. Participants completed self-report measures of symptoms, functioning, and mood, as well as three experimental tasks (i) visual-probe task measuring attentional bias to illness (somatic symptoms and disability) versus neutral words, (ii) interpretive bias task measuring positive versus somatic interpretations of ambiguous information, and (iii) the Attention Network Test measuring general attentional control. RESULTS: Compared to controls, Dutch and UK participants with CFS showed a significant attentional bias for illness-related words and were significantly more likely to interpret ambiguous information in a somatic way. These effects were not moderated by attentional control. There were no significant differences between the Dutch and UK CFS groups on attentional bias, interpretation bias, or attentional control scores. CONCLUSION: This study replicated the main findings of the UK study, with a Dutch CFS population, indicating that across these two cultures, people with CFS demonstrate biases in how somatic information is attended to and interpreted. These illness-specific biases appear to be unrelated to general attentional control deficits.

Chronic fatigue syndrome (CFS/ME) symptom-based phenotypes and 1-year treatment outcomes in two clinical cohorts of adult patients in the UK and The Netherlands.

OBJECTIVE: We previously described symptom-based chronic fatigue syndrome (CFS/ME) phenotypes in clinical assessment data from 7041 UK and 1392 Dutch adult CFS/ME patients. Here we aim to replicate these phenotypes in a more recent UK patient cohort, and investigate whether phenotypes are associated with 1-year treatment outcome. METHODS: 12 specialist CFS/ME services (11 UK, 1 NL) recorded the presence/absence of 5 symptoms (muscle pain, joint pain, headache, sore throat, and painful lymph nodes) which can occur in addition to the 3 symptoms (post-exertional malaise, cognitive dysfunction, and disturbed/unrefreshing sleep) that are present for almost all patients. Latent Class Analysis (LCA) was used to assign symptom profiles (phenotypes). Multinomial logistic regression models were fitted to quantify associations between phenotypes and overall change in health 1year after the start of treatment. RESULTS: Baseline data were available for N=918 UK and N=1392 Dutch patients, of whom 416 (45.3%) and 912 (65.5%) had 1-year follow-up data, respectively. 3- and 4-class phenotypes identified in the previous UK patient cohort were replicated in the new UK cohort. UK patients who presented with 'polysymptomatic' and 'pain-only' phenotypes were 57% and 67% less likely (multinomial odds ratio (MOR) 0.43 (95% CI 0.19-0.94) and 0.33 (95% CI 0.13-0.84)) to report that their health was "very much better" or "much better" than patients who presented with an 'oligosymptomatic' phenotype. For Dutch patients, polysymptomatic and pain-only phenotypes were associated with 72% and 55% lower odds of improvement (MOR 0.28 (95% CI 0.11, 0.69) and 0.45 (95% CI 0.21, 0.99)) compared with oligosymptomatic patients. CONCLUSIONS: Adult CFS/ME patients with multiple symptoms or pain symptoms who present for specialist treatment are much less likely to report favourable treatment outcomes than patients who present with few symptoms.

Long-term follow-up after cognitive behaviour therapy for chronic fatigue syndrome.

OBJECTIVE: Cognitive behaviour therapy (CBT) is an effective treatment for chronic fatigue syndrome (CFS). Main aim was to determine whether treatment effects were maintained up to 10years after treatment. METHODS: Participants (n=583) of previously published studies on the effects of CBT for CFS were contacted for a long-term follow-up assessment. They completed questionnaires on main outcomes fatigue severity (CIS) and physical functioning (SF-36). The course of these outcomes since post-treatment assessment was examined using mixed model analyses. RESULTS: Between 21 and 125months after finishing CBT, 511 persons (response rate 88%) completed a follow-up assessment. At follow-up, mean fatigue severity was significantly increased to 37.60 (SD=12.76) and mean physical functioning significantly decreased to 73.16 (SD=23.56) compared to post-treatment assessment. At follow-up still 37% of the participants had fatigue scores in the normal range and 70% were not impaired in physical functioning. CONCLUSION: Positive effects of CBT for CFS on fatigue and physical functioning were partly sustained at long-term follow-up. However, a subgroup of patients once again reported severe fatigue, and compromised physical functioning. Further research should elucidate the reasons for this deterioration to facilitate the development of treatment strategies for relapse prevention.

Severe fatigue in type 1 diabetes: Exploring its course, predictors and relationship with HbA1c in a prospective study.

AIMS: To prospectively identify the course of severe fatigue, its predictors and the relationship with HbA1c in patients with type 1 diabetes. METHODS: 214 adult patients completed questionnaires on fatigue severity and fatigue-related factors at baseline. HbA1c was retrieved from medical records. After 43months, fatigue severity and HbA1c were reassessed in 194 patients. A logistic regression analysis was used to determine predictors of severe fatigue at follow-up with various cognitive-behavioral and clinical factors as potential predictors. The relationship between fatigue and HbA1c was investigated in a sub-analysis by differentiating between patients with suboptimal glucose control [HbA1c>7% (53mmol/mol)] and optimal glucose control [HbA1c⩽7% (53mmol/mol)]. RESULTS: The prevalence of severe fatigue was 40% at baseline and 42% at follow-up. In three out of four severely fatigued patients at baseline (76%), severe fatigue persisted over time. More depressive symptoms, more pain, sleep disturbances, lower self-efficacy concerning fatigue, less confidence in diabetes self-care, more fatigue severity at baseline and more diabetes complications predicted severe fatigue at follow-up. Over time, HbA1c at baseline was positively associated with fatigue severity at follow-up in both groups (suboptimal glucose control: r=.18, p<.05; optimal glucose control: r=.09, p<.05). CONCLUSIONS: About three quarters of fatigued[corrected] patients with type 1 diabetes suffer from persistent fatigue. Aside from the number of diabetes complications, no clinical factors explained the persistence of fatigue. HbA1c and fatigue were weakly associated in a sub-analysis. Since the strongest predictors of severe fatigue were cognitive-behavioral factors, behavioral interventions might be effective in decreasing fatigue.

Chronic fatigue syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands.

OBJECTIVE: Studies have provided evidence of heterogeneity within chronic fatigue syndrome (CFS), but few have used data from large cohorts of CFS patients or replication samples. METHODS: 29 UK secondary-care CFS services recorded the presence/absence of 12 CFS-related symptoms; 8 of these symptoms were recorded by a Dutch tertiary service. Latent Class Analysis (LCA) was used to assign symptom profiles (phenotypes). Regression models were fitted with phenotype as outcome (in relation to age, sex, BMI, duration of illness) and exposure (in relation to comorbidities and patient-reported measures). RESULTS: Data were available for 7041 UK and 1392 Dutch patients. Almost all patients in both cohorts presented with post-exertional malaise, cognitive dysfunction and disturbed/unrefreshing sleep, and these 3 symptoms were excluded from LCA. In UK patients, six phenotypes emerged: 'full' polysymptomatic (median 8, IQR 7-9 symptoms) 32.8%; 'pain-only' (muscle/joint) 20.3%; 'sore throat/painful lymph node' 4.5%; and 'oligosymptomatic' (median 1, IQR 0-2 symptoms) 4.7%. Two 'partial' polysymptomatic phenotypes were similar to the 'full' phenotype, bar absence of dizziness/nausea/palpitations (21.4%) or sore throat/painful lymph nodes (16.3%). Women and patients with longer duration of illness were more likely to be polysymptomatic. Polysymptomatic patients had more severe illness and more comorbidities. LCA restricted to 5 symptoms recorded in both cohorts indicated 3 classes (polysymptomatic, oligosymptomatic, pain-only), which were replicated in Dutch data. CONCLUSIONS: Adults with CFS may have one of 6 symptom-based phenotypes associated with sex, duration and severity of illness, and comorbidity. Future research needs to determine whether phenotypes predict treatment outcomes, and require different treatments.

Construct Validation of a Multidimensional Computerized Adaptive Test for Fatigue in Rheumatoid Arthritis.

OBJECTIVE: Multidimensional computerized adaptive testing enables precise measurements of patient-reported outcomes at an individual level across different dimensions. This study examined the construct validity of a multidimensional computerized adaptive test (CAT) for fatigue in rheumatoid arthritis (RA). METHODS: The 'CAT Fatigue RA' was constructed based on a previously calibrated item bank. It contains 196 items and three dimensions: 'severity', 'impact' and 'variability' of fatigue. The CAT was administered to 166 patients with RA. They also completed a traditional, multidimensional fatigue questionnaire (BRAF-MDQ) and the SF-36 in order to examine the CAT's construct validity. A priori criterion for construct validity was that 75% of the correlations between the CAT dimensions and the subscales of the other questionnaires were as expected. Furthermore, comprehensive use of the item bank, measurement precision and score distribution were investigated. RESULTS: The a priori criterion for construct validity was supported for two of the three CAT dimensions (severity and impact but not for variability). For severity and impact, 87% of the correlations with the subscales of the well-established questionnaires were as expected but for variability, 53% of the hypothesised relations were found. Eighty-nine percent of the items were selected between one and 137 times for CAT administrations. Measurement precision was excellent for the severity and impact dimensions, with more than 90% of the CAT administrations reaching a standard error below 0.32. The variability dimension showed good measurement precision with 90% of the CAT administrations reaching a standard error below 0.44. No floor- or ceiling-effects were found for the three dimensions. CONCLUSION: The CAT Fatigue RA showed good construct validity and excellent measurement precision on the dimensions severity and impact. The dimension variability had less ideal measurement characteristics, pointing to the need to recalibrate the CAT item bank with a two-dimensional model, solely consisting of severity and impact.

A comparison of patients with Q fever fatigue syndrome and patients with chronic fatigue syndrome with a focus on inflammatory markers and possible fatigue perpetuating cognitions and behaviour.

OBJECTIVE: Comparison of Q fever fatigue syndrome (QFS) and chronic fatigue syndrome (CFS) patients, with a focus on markers of inflammation and fatigue-related cognitive-behavioural variables. METHODS: Data from two independent prospective studies on QFS (n=117) and CFS (n=173), respectively, were pooled and analyzed. RESULTS: QFS patients were less often female, had a higher BMI, and had less often received treatment for depression before the onset of symptoms. After controlling for symptom duration and correcting for differences in diagnostic criteria for QFS and CFS with respect to the level of impairment and the presence of additional symptoms, differences in the proportion of females and BMI remained significant. After correction, QFS patients were also significantly older. In all analyses QFS patients were as fatigued and distressed as CFS patients, but reported less additional symptoms. QFS patients had stronger somatic attributions, and higher levels of physical activity. No differences were found with regard to inflammatory markers and in other fatigue-related cognitive-behavioural variables. The relationship between cognitive-behavioural variables and fatigue, previously established in CFS, could not be confirmed in QFS patients with the exception of the negative relationship between physical activity and fatigue. CONCLUSION: Differences and similarities between QFS and CFS patients were found. Although the relationship between perpetuating factors and fatigue previously established in CFS could not be confirmed in QFS patients, the considerable overlap in fatigue-related cognitive-behavioural variables and the relationship found between physical activity and fatigue may suggest that behavioural interventions could reduce fatigue severity in QFS patients.

Testing the efficacy of web-based cognitive behavioural therapy for adult patients with chronic fatigue syndrome (CBIT): study protocol for a randomized controlled trial.

BACKGROUND: Cognitive behavioural therapy (CBT) is an effective treatment for fatigue and disabilities in patients with chronic fatigue syndrome (CFS). However, treatment capacity is limited. Providing web-based CBT and tailoring the amount of contact with the therapist to the individual needs of the patient may increase the efficiency of the intervention. Web-based CBT for adolescents with CFS has proven to be effective in reducing fatigue and increasing school attendance. In the proposed study the efficacy of a web-based CBT intervention for adult patients with CFS will be explored. Two different formats of web-based CBT will be tested. In the first format named protocol driven feedback, patients report on their progress and receive feedback from a therapist according to a preset schedule. In the second format named support on demand, feedback and support of the therapist is only given when patients ask for it. The primary objective of the study is to determine the efficacy of a web-based CBT intervention on fatigue severity. METHOD/DESIGN: A randomized clinical trial will be conducted. Two-hundred-forty adults who have been diagnosed with CFS according to the US Centers for Disease Control and Prevention (CDC) consensus criteria will be recruited and randomized to one of three conditions: web-based CBT with protocol driven feedback, web-based CBT with support on demand, or wait list. Feedback will be delivered by therapists specialized in CBT for CFS. Each of the web-based CBT interventions will be compared to a wait list condition with respect to its effect on the primary outcome measure; fatigue severity. Secondary outcome measures are level of disability, physical functioning, psychological distress, and the proportion of patients with clinical significant improvement in fatigue severity. Outcomes will be assessed at baseline and six months post randomization. The web-based CBT formats will be compared with respect to the time therapists need to deliver the intervention. DISCUSSION: As far as we know this is the first randomized controlled trial (RCT) that evaluates the efficacy of a web-based CBT intervention for adult patients with CFS. TRIAL REGISTRATION: NTR4013.

A web-based cognitive behaviour therapy for chronic fatigue in type 1 diabetes (Dia-Fit): study protocol for a randomised controlled trial.

BACKGROUND: Fatigue is frequently reported by patients with type 1 diabetes mellitus. A recent study showed that 40 % of patients experienced severe fatigue that lasted for more than six months and was accompanied by substantial impairments in daily functioning. Currently, there is no effective treatment available for chronic fatigue in patients with type 1 diabetes. Cognitive behaviour therapy aimed at cognitions and behaviours that perpetuate fatigue is effective in reducing fatigue in other chronic diseases. Recent research showed that these cognitions and behaviours are also potential determinants of fatigue in type 1 diabetes. We designed Dia-Fit, a web-based cognitive behaviour therapy for severe and chronic fatigue in patients with type 1 diabetes. This patient-tailored intervention is aimed at reducing fatigue by changing cognitions and behaviours assumed to maintain fatigue. The efficacy of Dia-Fit will be investigated in this study. METHODS/DESIGN: A randomised controlled trial will be conducted in 120 patients with type 1 diabetes who are chronically and severely fatigued. Patients will be randomised to a treatment or waiting list group. The treatment group will receive Dia-Fit, a blended care therapy consisting of up to eight internet modules and face-to-face sessions with a therapist during a five-month period. The treatment will be tailored to the fatigue-maintaining cognitions and behaviours that are relevant for the patient and are determined at baseline. The waiting list group will receive Dia-Fit after a waiting period of five months. The primary outcome measure is fatigue severity. Secondary outcome measures are functional impairment and glucose control determined by haemoglobin A1c and blood glucose variability. DISCUSSION: To our knowledge, this is the first study investigating the efficacy of a cognitive behavioural intervention for chronic fatigue in patients with type 1 diabetes. TRIAL REGISTRATION: Dutch trial register NTR4312 (10 December 2013).

Working mechanism of a multidimensional computerized adaptive test for fatigue in rheumatoid arthritis.

BACKGROUND: This paper demonstrates the mechanism of a multidimensional computerized adaptive test (CAT) to measure fatigue in patients with rheumatoid arthritis (RA). A CAT can be used to precisely measure patient-reported outcomes at an individual level as items are consequentially selected based on the patient's previous answers. The item bank of the CAT Fatigue RA has been developed from the patients' perspective and consists of 196 items pertaining to three fatigue dimensions: severity, impact and variability of fatigue. METHODS: The CAT Fatigue RA was completed by fifteen patients. To test the CAT's working mechanism, we applied the flowchart-check-method. The adaptive item selection procedure for each patient was checked by the researchers. The estimated fatigue levels and the measurement precision per dimension were illustrated with the selected items, answers and flowcharts. RESULTS: The CAT Fatigue RA selected all items in a logical sequence and those items were selected which provided the most information about the patient's individual fatigue. Flowcharts further illustrated that the CAT reached a satisfactory measurement precision, with less than 20 items, on the dimensions severity and impact and to somewhat lesser extent also for the dimension variability. Patients' fatigue scores varied across the three dimensions; sometimes severity scored highest, other times impact or variability. The CAT's ability to display different fatigue experiences can improve communication in daily clinical practice, guide interventions, and facilitate research into possible predictors of fatigue. CONCLUSIONS: The results indicate that the CAT Fatigue RA measures precise and comprehensive. Once it is examined in more detail in a consecutive, elaborate validation study, the CAT will be available for implementation in daily clinical practice and for research purposes.

Acceptance of New Technology: A Usability Test of a Computerized Adaptive Test for Fatigue in Rheumatoid Arthritis.

BACKGROUND: Little is known about the acceptance and usability of computerized adaptive tests (CATs) among patients with rheumatoid arthritis (RA). The main difference between completing a CAT and a traditional questionnaire concerns item presentation. CATs only provide one item at a time on the screen, and skipping forward or backward to review and change already given answers is often not possible. OBJECTIVE: The objective of this study was to examine how patients with RA experience a Web-based CAT for fatigue. METHODS: In individual sessions, participants filled in the CAT while thinking aloud, and were subsequently interviewed about their experience with the new instrument. The technology acceptance model (TAM) was used to structure the results. RESULTS: The participants were 15 patients with RA. They perceived the CAT as clear, brief, and easy to use. They were positive about answering one question per screen, the changing response options, layout, progress bar, and item number. There were 40% (6/15) of the participants that also mentioned that they experienced the completion of the CAT as useful and pleasant, and liked the adaptive test mechanism. However, some participants noted that not all items were applicable to everybody, and that the wordings of questions within the severity dimension were often similar. CONCLUSIONS: Participants perceived the "CAT Fatigue RA" as easy to use, and also its usefulness was expressed. A 2.0 version has been improved according to the participants' comments, and is currently being used in a validation study before it will be implemented in daily clinical practice. Our results give a first indication that CAT methodology may outperform traditional questionnaires not merely on measurement precision, but also on usability and acceptance valuation.

Items and dimensions for the construction of a multidimensional computerized adaptive test to measure fatigue in patients with rheumatoid arthritis.

OBJECTIVES: Development of an item pool to construct a future computerized adaptive test (CAT) for fatigue in rheumatoid arthritis (RA). The item pool was based on the patients' perspective and examined for face and content validity previously. This study assessed the fit of the items with seven predefined dimensions and examined the item pool's dimensionality structure in statistical terms. STUDY DESIGN AND SETTING: A total of 551 patients with RA participated in this study. Several steps were conducted to come from an explorative item pool to a psychometrically sound item bank. The item response theory (IRT) analysis using the generalized partial credit model was conducted for each of the seven predefined dimensions. Poorly fitting items were removed. Finally, the best possible multidimensional IRT (MIRT) model for the data was identified. RESULTS: In IRT analysis, 49 items showed insufficient item characteristics. Items with a discriminative ability below 0.60 and/or model misfit effect sizes greater than 0.10 were removed. Factor analysis on the 196 remaining items revealed three dimensions, namely severity, impact, and variability of fatigue. The dimensions were further confirmed in MIRT model analysis. CONCLUSION: This study provided an initially calibrated item bank and showed which dimensions and items can be used for the development of a multidimensional CAT for fatigue in RA.

Fatigue and factors related to fatigue in rheumatoid arthritis: a systematic review.

OBJECTIVE: Although patients with rheumatoid arthritis (RA) experience fatigue, little is known about its causes and consequences, and a fully developed theoretical model explaining the experience of fatigue in RA is lacking. Our goal was to systematically review studies in RA that examined factors related to fatigue to gain more insight into its possible causes and consequences. METHODS: Medline, Web of Science, Scopus, and PsycINFO were searched for relevant studies. All studies with RA samples about the relationship between fatigue and other variables that defined dependent and independent variables and used multivariate statistical methods were preliminarily included. After reviewing 129 full texts, we identified 25 studies on possible causes of fatigue and 17 studies on possible consequences of fatigue. RESULTS: The studies found possible causes of fatigue in illness-related aspects, physical functioning, cognitive/emotional functioning, and social aspects. Additionally, being a woman was related to higher levels of fatigue. Inflammatory activity showed an unclear relationship with fatigue in RA. Possible consequences of fatigue were also found among illness-related aspects, physical functioning, cognitive/emotional functioning, and social aspects. The strongest evidence for a relationship between fatigue and other variables was found regarding pain, physical functioning, and depression. CONCLUSION: This review summarizes the current knowledge in the field in order to inform future research on causes and consequences of fatigue in RA. However, the results are based on cross-sectional and longitudinal studies with different designs and different fatigue scales. For a better identification of causal associations between fatigue in RA and related factors, longitudinal prospective designs with adequate fatigue measurements are suggested.

Which dimensions of fatigue should be measured in patients with rheumatoid arthritis? A Delphi study.

OBJECTIVE: Rheumatoid arthritis (RA) patients experience fatigue as a multidimensional symptom. The aim of the present study was to use health professionals and patients alike to identify which dimensions of fatigue should be measured in RA. METHODS: Twelve fatigue dimensions were constructed, based on items from traditional questionnaires and items generated from interviews. Health professionals and patients evaluated these dimensions, related to an initial pool of 294 items, in a Delphi procedure. Dimensions were selected if rated important by at least 80% of the participants. RESULTS: Ten rheumatologists, 20 nurses and 15 patients participated. All fatigue dimensions were selected directly (severity, frequency, duration, changes in fatigue, perceived causes of fatigue, energy, sleep/rest, body feeling, cognition/concentration, coping, negative emotions/mood and consequences). No additional dimensions emerged from participants' comments and suggestions. CONCLUSIONS: This study revealed 12 fatigue dimensions. This underlines the multidimensionality of fatigue in RA and the need for comprehensive measurement.

Selection of items for a computer-adaptive test to measure fatigue in patients with rheumatoid arthritis: a Delphi approach.

PURPOSE: Computer-adaptive tests (CATs) can measure precisely at individual level with few items selected from an item bank. Our aim was to select fatigue items to develop a CAT for rheumatoid arthritis (RA) and include expert opinions that are important for content validity of measurement instruments. METHODS: Items were included from existing fatigue questionnaires and generated from interview material. In a Delphi procedure, rheumatologists, nurses, and patients evaluated the initial pool of 294 items. Items were selected for the CAT development if rated as adequate by at least 80% of the participants (when 50% or less agreed, they were excluded). Remaining items were adjusted based on participants' comments and re-evaluated in the next round. The procedure stopped when all items were selected or rejected. RESULTS: A total of 10 rheumatologists, 20 nurses, and 15 rheumatoid arthritis patients participated. After the first round, 96 of 294 items were directly selected. Nine items were directly excluded, and remaining items were adjusted. In the second round, 124 items were presented for re-evaluation. Ultimately, 245 items were selected. CONCLUSION: This study revealed a qualitatively evaluated item pool to be used for the item bank/CAT development. The Delphi procedure is a beneficial approach to select adequate items for measuring fatigue in RA.