Assessment of functional capacity in fibromyalgia. Comparative analysis of construct validity of three functional scales

ObjectiveTo compare the construct validity of three functional capacity questionnaires in patients with fibromyalgia.Patients and methodsTransversal multicentric study of 301 patients from fifteen rheumatology outpatient clinics in Spain. Scores of Health Assessment Questionnaire (HAQ), Fibromyalgia Health Assessment Questionnaire (FHAQ) and the physical function scale of the Fibromyalgia Impact Questionnaire (PF-FIQ) were compared with extreme groups of patients defined by four external indirect measures: 6 Min Walk Test, a modified Borg Fatigue Scale, Lumbar Spine Flexion Test and Patient Global Passive Mobility Assessment. Standardized differences were determined and correlation coefficients were calculated between the three questionnaires scores.ResultsAll three questionnaires showed good construct validity, but the results obtained with the PF-FIQ were poorer. Correlations between HAQ and FHAQ were very high (0.92), but correlations between these two questionnaires and PF-FIQ were only moderate (0.59).ConclusionsHAQ and FHAQ are more valid measures of functional capacity than the PF-FIQ. HAQ could be substituted by FHAQ in some settings because of its shorter format (only 8 items).     

Results of the Health Assessment Questionnaire for Japanese patients with systemic sclerosis--measuring functional impairment in systemic sclerosis versus other connective tissue diseases

OBJECTIVE: To evaluate the physical functional impairment in patients with systemic sclerosis (SSc) using the Health Assessment Questionnaire (HAQ) and to estimate the correlation of HAQ scores with the severity of SSc. METHODS: One hundred and twenty-four outpatients with connective tissue disease, including 50 patients with SSc, were evaluated using the HAQ. Twelve patients were classified as having diffuse cutaneous SSc (dSSc) and 38 limited cutaneous SSc (lSSc). The severity classification and the guidelines for treatment (2004) were applied to Japanese SSc patients in order to evaluate the relationship between HAQ scores and disease activity in patients with multiple organ involvement. RESULTS: In dSSc the HAQ category scores for eating, walking, grip, activity and the HAQ-disability index (HAQ-DI) showed the greatest deficits in all disease groups. The severity of disease activity correlated significantly with the scores for walking, reach, and the HAQ-DI. The severity of joint, heart, and pulmonary hypertension were correlated independently with the HAQ-DI score by multiple linear regression analysis. CONCLUSION: Patients with dSSc suffer greater functional impairment than patients with other connective tissue diseases, and improvements in hand use and walking represent very important targets for both drug development and rehabilitation. As improvement in organ involvement (joints, heart as well as pulmonary hypertension) can lead to reduced functional impairment, they constitute an important target for therapy in SSc.     

Toward a multidimensional Health Assessment Questionnaire (MDHAQ): assessment of advanced activities of daily living and psychological status in the patient-friendly health assessment questionnaire format.

OBJECTIVE: To develop components of a multidimensional Health Assessment Questionnaire (MDHAQ) through the addition of new items in the "patient-friendly" HAQ format, including advanced activities of daily living (ADL), designed to overcome "floor effects" of the HAQ and modified HAQ (MHAQ) in which patients may report normal scores although they experience meaningful functional limitations, and psychological items, designed to screen efficiently for psychological distress in routine care. METHODS: The new MDHAQ items, as well as scales for pain, fatigue, helplessness, and global health status on a 2-page questionnaire, were completed by 688 consecutive patients with various rheumatic diseases, including 162 with rheumatoid arthritis (RA), 114 with fibromyalgia, 63 with osteoarthritis, 34 with systemic lupus erythematosus, 20 with vasculitis, 18 with psoriatic arthritis, 16 with scleroderma, and 261 with various other rheumatic diseases, over 2 years at a weekly academic rheumatology clinic. RESULTS: The new MDHAQ items have good test-retest reliability and face validity. MHAQ scores were highest in patients with RA, and scores for other scales were highest in patients with fibromyalgia. On the advanced ADL, 58% of patients reported difficulty with errands, 68% with climbing stairs, 79% with walking two miles, 87% with participating in sports and games, and 94% with running or jogging two miles. On the psychological items, 75% of patients reported difficulty with sleep, 63% with stress, 61% with anxiety, and 57% with depression. Normal MHAQ scores were reported by 23% of patients and normal HAQ scores by 16% of patients who completed these questionnaires, while fewer than 5% had normal scores on the MDHAQ. CONCLUSION: The MDHAQ items overcome in large part the "floor effects" seen on the HAQ and MHAQ, and are useful to screen for problems with sleep, stress, anxiety, and depression in the "patient-friendly" HAQ format. These data support the value of completion of a simple 2-page patient questionnaire by each patient at each visit to a rheumatologist.     

Validation of French version of the Scleroderma Health Assessment Questionnaire (SSc HAQ)

The modified Scleroderma Health Assessment Questionnaire (SSc HAQ) is a functional score to assess systemic sclerosis (SSc) comprising the HAQ disease index (HAQ-DI) plus five specific visual analogue scales (VAS). Since it was validated in English-speaking patients only, its general use in any other language necessitates prior cross-cultural adaptation and validation. We designed this study to assess its value in French-speaking patients and to validate the French version according to international recommendations. We elaborated a French version using the forward-backward method. We then validated its psychometric properties with 100 consecutive SSc French-speaking patients who had undergone simultaneous clinical and paraclinical examination. In addition, we calculated the SSc HAQ score, a new outcome measure, which is obtained by pooling the eight domains from the HAQ-DI with the five organ VAS. Our study confirmed the psychometric properties of the SSc HAQ in non-English-speaking patients with (a) structural validity: the major component analysis, performed on the HAQ-DI and the five VAS, yielding a two-factor structure; (b) convergent validity: with high correlation coefficients between the SSc HAQ score and the physical component score of the SF-36 (r=–0.74, p<0.0001); (c) discriminant validity: the SSc HAQ score was better in patients with limited than with diffuse SSc (0.5±0.5 vs 1.1±0.7, respectively, p<0.0001) in relation to the number of clinical involvements; (d) reproducibility was high using the test-retest procedure (r=0.98). This study showed the value of the SSc HAQ, which is a simple, discriminant, reproducible self-administered questionnaire to evaluate French-speaking SSc patients. In addition, we suggest the use of a new outcome measure, the SSc HAQ score, to assess this systemic disease more accurately.Grant support was provided by the Délégation Régionale à la Recherche Clinique (DRRC), Assistance Publique-Hôpitaux de Paris (AP-HP) and the French Ministry of Health (Programme Hospitalier de Recherche Clinique: PHRC 1997 AOM 97–030)     

Rasch analysis of the Western Ontario MacMaster Questionnaire (WOMAC) in 2205 patients with osteoarthritis, rheumatoid arthritis, and fibromyalgia

OBJECTIVE: Advances in health measurement have led to the application of Rasch Item Response Theory (IRT) analysis (Rasch analysis) to evaluate instruments measuring health status and quality of life of patients, including the Health Assessment Questionnaire and SF-36. This study investigated the extent to which the Western Ontario MacMaster osteoarthritis questionnaire (WOMAC) satisfies the Rasch model, particularly in respect to unidimensionality, item separation, and linearity. METHODS: The study included a total of 2205 patients, 1013 with rheumatoid arthritis (RA), 655 with osteoarthritis of the knee or hip (OA), and 537 with fibromyalgia. All patients completed the WOMAC as part of a longitudinal study of rheumatic disease outcomes. To examine whether the WOMAC pain and function scales each fits the Rasch model, the Winsteps program was used to assess item difficulty, scale unidimensionality, item separation, and linearity. RESULTS: Although the WOMAC worked best in OA, regardless of disorder, both the pain and function scales were unidimensional, had adequate item separation, and had a long range (25-150) of linearity in the function scale. Several functional items, however, had a high information weight fit (INFIT) statistic, indicating poor fit to the model. These items included "getting in and out of the bath" and "going down stairs." CONCLUSION: The WOMAC generally satisfies the requirements of Rasch item response theory across all disorders studied, and is an appropriate measure of lower body function in OA, RA and fibromyalgia. Although some individual items do not fit well, it is not likely that removing such items would result in more than overall minimal differences, and it will be difficult to remove traces of multidimensionality while keeping the central constructs of progressive lower body musculoskeletal abnormality intact. In addition, it is possible that a "purer", still more unidimensional instrument would be less useful in clinical trials and epidemiological studies by restricting the range of the scale.     

Comparison of the Health Assessment Questionnaire (HAQ) and the modified HAQ (MHAQ) in patients with rheumatoid arthritis

OBJECTIVES: Physical disability in patients with rheumatoid arthritis (RA) is often assessed by questionnaires. We compared the Health Assessment Questionnaire (HAQ) with the modified HAQ (MHAQ) in a cohort of RA patients across various levels of disability, and examined correlations with other measures of physical function. METHODS: Patients with RA (n = 182) completed self-report questionnaires assessing functional capacity. Instruments included the MHAQ and HAQ completed separately, as well as SF-36 and the Arthritis Impact Measurement Scales (AIMS). Scores from unadjusted and adjusted HAQ were compared with MHAQ at various disability levels. RESULTS: A clear ceiling effect with aggregation of normal scores for physical function was observed for MHAQ (23%) and HAQ (12%), but not for SF-36 (4%) or AIMS (5%). The correlations between adjusted/unadjusted HAQ and MHAQ scores were 0.85/0.88. A discrepancy in HAQ and MHAQ scores was observed in patients with high levels of disability, especially when MHAQ was compared with the adjusted final HAQ score. Adjustment of HAQ by aids or help increased the final score by an average of 0.15, and both adjusted and unadjusted HAQ scores were numerically clearly higher (mean 0.45 and 0.30, respectively) than the MHAQ score. CONCLUSION: The present findings indicate that MHAQ and HAQ may be applicable as measures of physical capacity in RA patients, but clinicians and researchers should select the appropriate instrument for the setting, and be aware of differences in scores, especially at different disability levels.     

Measuring the meaning of disability in rheumatoid arthritis: the Personal Impact Health Assessment Questionnaire (PI HAQ)

BACKGROUND: Measurement of disability in rheumatoid arthritis is often used to support treatment decisions and outcome assessments, but is used without reference to the impact of disability on individual patients. OBJECTIVE: To develop and validate a scale to measure individual values for functions, which is used to weight the level of an individual patient's functional loss and thus calculate the personal impact of disability. METHODS: In four linked studies, first the phraseology for values was explored to develop a stem question for the value scale couched in terms patients understand (face validity). Then short and long versions of the value scale were compared (content validity) and tests of internal consistency and short term reliability undertaken (criterion validity). Finally, the value scale was examined for long term reliability and agreement with expected variables (criterion and construct validity), after which personal impact scores were calculated and their construct validity examined. RESULTS: Patients understand the concept of values, and a positively phrased stem question was developed for the value scale, for which a short version was reasonably equivalent to a long version. The value scale was reliable over one week (96% changed by <1 point) with positive interitem correlation. Reasonable six and 12 month reliability was shown (52% changed by <0.5 points), and the value scale was independent of disability and clinical, psychological, personality, and social support variables. Personal impact scores were then calculated by using the value scores to weight disability scores. Impact scores varied widely between patients of similar disability. Personal impact for disability showed convergent validity with dissatisfaction with disability, perceived increase in disability, increased disease activity, worse psychological status, low social support, and time trade off for disability. It discriminated between patients with low and high dissatisfaction with disability, life satisfaction, depression, pain, and helplessness. CONCLUSION: This individualised personal impact scale should lend meaning to disability scores, improving the interpretation of clinical and research data.     

Comparison of the Indian version of Health Assessment Questionnaire Score and Short Form 36 Physical Function Score in rheumatoid arthritis using Rasch analysis

ObjectiveThe health assessment questionnaire (HAQ) has been modified by many investigators to suit the culture and lifestyle of Indian population and these have been validated using traditional approaches. The goal of this study was to further validate the Indian version of HAQ published in 2002 by modern psychometric analysis, specifically by examining fit of the scale's data to the Rasch measurement model.MethodsA cross-sectional study was performed on 46 patients with rheumatoid arthritis (RA) from a single center in western India. Demographic characteristics, pain score and global perception of health were recorded on visual analogue scale. Functional outcome was assessed with the Indian HAQ and Short Form 36 physical function (SF 36-PF). Rasch analysis was performed to examine the property of various measures and to compare them on a common scale.ResultThe mean age ± SD was 45 ± 14.19 years and mean duration was 35.5 ± 52 months. 82.6% were women. The Indian HAQ highly correlated with SF 36-PF (r = 0.812, P < 0.001). Both the indices showed a moderate correlation with fatigue, pain, global health perception as well as disease activity scores (DAS28). Both the indices satisfied the Rasch model and were unidimensional with adequate person separation and reliability. Nine out of the 12 items in Indian HAQ were fitting in the Rasch model while in SF 36-PF scale nine out of 10 were fitting in the Rasch model. Three items in the HAQ (a) sitting cross-legged, (b) bending, and (c) lifting a cup were not fitting in the Rasch model, while one item of SF 36 ‘walking one block’, was not fitting in the Rasch model. 2.2% of patients assessed by Indian HAQ had 0 score (floor effect), while none had 3 score (ceiling effect), while 15.2% had maximum SF 36-PF score (ceiling effect) while none had 100 score (floor effect).ConclusionBoth Indian HAQ and SF 36-PF provide unidimensional measure of physical functioning in RA. SF 36-PF has significant psychometric advantage over Indian HAQ in RA in our cohort.     

Cross-cultural adaptation and validation of the Brazilian version of the Scleroderma Health Assessment Questionnaire (SHAQ)

The Scleroderma Health Assessment Questionnaire (SHAQ) is a feasible multisystem specific tool that has been extensively used as an additional assessment for systemic sclerosis (SSc). The aim of this study is to cross-culturally adapt and validate the Brazilian version of the SHAQ. Construct validity was assessed based on the correlations between SHAQ and both the Medical Outcomes Survey Short Form 36 version 2 (SF-36v2?) and the Health Assessment Questionnaire Disability Index (HAQ-DI). The correlation between the SHAQ and disease severity was assessed by Spearman's correlation coefficient. The reproducibility of the SHAQ was evaluated by the intraclass correlation coefficient (ICC). Among the 151 consecutive outpatients evaluated, 59 % had limited SSc subtype. The overall disease severity visual analog scale (VAS) of the SHAQ was statistically significantly correlated to HAQ-DI, pain VAS, and the SF-36v2? physical component summary score (r?=?0.595, r?=?0.612, and r?=??0.582, respectively; p?<?0.001). Further analysis of all SF-36v2? components revealed statistically significant correlations between overall disease severity VAS and bodily pain (r?=??0.621, p?<?0.001), vitality (r?=??0.544, p?<?0.001), physical function (r?=??0.510, p?<?0.001), and role limitation-physical dimensions (r?=??0.505, p?<?0.001). Moreover, digestive, pulmonary, and overall disease severity VASs were statistically significantly correlated to the number of organs involved (r?=?0.178, p?=?0.029; r?=?0.214, p?=?0.008; r?=?0.282, p?<?0.001). We also demonstrated high reproducibility for SHAQ (ICC?=?0.757, 95 % confidence interval?=?0.636–0.842). The Brazilian version of the SHAQ demonstrated both construct and discriminant validities as well as good reproducibility.     

Cross-cultural adaptation and validation of the Japanese version of the Childhood Health Assessment Questionnaire (CHAQ)

To assess cross-cultural adaptation, and to validate the parent's version of a health-related quality-of-life instrument, the Childhood Health Assessment Questionnaire (CHAQ) was investigated after its translation into Japanese. A total of 132 subjects were enrolled: 63 patients with juvenile idiopathic arthritis (JIA) (34 systemic and 29 polyarticular) and 69 healthy children. The CHAQ distinguished clinically between healthy subjects and the two JIA subtypes of patients. The average disability index (DI) scores for systemic JIA (sJIA) and polyarticular JIA (pJIA) patients and healthy subjects were 1.5, 1.2, and 0.0, respectively. All variables in the questionnaire were shown to be significant (P < 0.001). Patients with pJIA showed better correlation than those with sJIA. Significant correlation was seen in the polyarticular group with CRP, ESR, parents' VAS, the number of joints with pain, and the number of active joints. However, there was even a negative correlation between DI and parent's assessment of overall well-being for the sJIA group. The Japanese version of the CHAQ was a reliable and valid tool for the functional assessment of children with pJIA. Functional ability, as assessed by the CHAQ, may not be the main consideration of sJIA patients' parents when assessing their child's status.     

Validity and reliability of the Heart Disease Fact Questionnaire (HDFQ): a Rasch measurement model approach

AimThe aim of this study was to examine the validity and reliability of Turkish version of the Heart Disease Fact Questionnaire (HDFQ) as a measure to evaluate heart disease risk knowledge in individuals with diabetes.MethodsThis study was conducted in the primary care clinic on 326 individuals with type 2 diabetes. The Davis Method, Confirmatory Factor Analysis (CFA) and the Rasch Measurement Model used in the validity and reliability analyses.ResultsThe validity analysis results showed Turkish version of HDFQ was content valid. The results of CFA showed the index results were very good fit. All items of the scale and the HDFQ were fit to the Rasch model and the items did not contain any differential item function. Person Separation Index showed HDFQ is reliable tool.ConclusionsThe Rasch Model provides an alternative way in dealing with the challenges faced in classic methods and it is recommended to be used in health sciences. Thus, the results of this study are important. Results show that the Turkish version of the HDFQ can be used for determining awareness of heart disease risk as well as for assessing the effectiveness of implemented interventions among individuals with diabetes.     

Longitudinal comparison of the Health Assessment Questionnaire (HAQ) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)

OBJECTIVE: To compare the measurement properties of the generic Health Assessment Questionnaire (HAQ) and the disease-specific Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). METHODS: Physical function, pain, and radiographic progression were assessed in knee or hip osteoarthritis patients (n = 271) who had 2 radiographs that were at least 6 months apart from 6 ARAMIS (Arthritis, Rheumatism, and Aging Medical Information System) databanks. Data were compared at baseline and after a mean of 3.2 (SE 0.10) years. Correlation coefficients and standardized effect sizes (SES) were used to assess their relationship and responsiveness. RESULTS: The majority of items in the 2 function and pain scales overlapped and were highly and significantly correlated with each other at baseline and last assessments (function at baseline rs = 0.71 and function at last assessment rs = 0.79, P < 0.0001; pain at baseline rs = 0.70 and pain at last assessment rs = 0.76, P < 0.0001). The HAQ disability index and total knee score were more sensitive to detection of disease progression than the WOMAC (SES for HAQ = 0.27; SES for WOMAC = -0.05). CONCLUSION: Both instruments showed favorable measurement properties, with the HAQ having the advantages of being more sensitive to change and adaptable to a wide variety of diseases and conditions, which contribute to the generalizability of findings.     

Relative importance of the functional abilities comprising Health Assessment Questionnaire Disability Index among rheumatoid arthritis patients

The aim was to evaluate the relative importance of the 20 functions assessed by patients to produce the Health Assessment Questionnaire’s Disability Index (HAQ-DI). A systematic sample of 242 rheumatoid arthritis patients was drawn. Altogether 179 subjects returned acceptably filled questionnaire including perceived rheumatoid arthritis status in the 20 functions comprising the HAQ-DI. A separate complementary questionnaire was sent to 80 randomly chosen subjects. They were asked to estimate how important each of the same 20 items were in their everyday life using the VAS method. Completely answered complementary questionnaires were returned by 66 (88%) of the subsample. The relative importance of the functions assessed varied considerably. Men assessed the highest importance to the ability to walk outdoors on flat ground and women to dressing themselves, getting in and out of bed and washing and drying their body. For both genders the least important function was the ability to take a tub bath. The importance of all other functions except taking a tub bath was positively highly significantly correlated with the importance of each of the other functions. Factor analyses with one factor model showed high loadings on most functions, with the exception of ‘Take a tub bath’. The two-factor model formed one factor with loadings concentrating slightly more on ‘lower extremity’ and another on ‘upper extremity’. Assessment of RA patients’ functional status would benefit from further development of measures by giving relative weights from patients’ perspective to those functional abilities which are used for index computations.     

The Rapid Assessment of Disease Activity in Rheumatology (Radar) Questionnaire

Objective. This study documents the measurement properties of a brief, self-administered questionnaire of disease signs and symptoms in patients with rheumatoid arthritis. Methods. The Rapid Assessment of Disease Activity in Rheumatology (RADAR) questionnaire assesses joint pain/tenderness and clinical status. One hundred ninety-three pairs of RADAR forms were completed by 45 subjects and their assigned clinician evaluators. Results. Subject—clinician agreement (intraclass correlation coefficients [ICC]) for joint pain/tenderness and clinical status ranged from 0.52 to 0.87 (P = 0.0001), with 83% ≥0.65. The ICC for change in joint scores over 6 months was 0.83 (P = 0.0001). Conclusion. The 2-page RADAR questionnaire produces valid estimates of joint count and clinical status that are sensitive to change.     

Cross-cultural adaptation and validation of the Chinese version of the Health Assessment Questionnaire for the Spondyloarthropathies (HAQ-S)

The Health Assessment Questionnaire for Spondyloarthropathies (HAQ-S) is a commonly used questionnaire to evaluate function and health status of patients with ankylosing spondylitis (AS). The objective of this study was to cross-culturally adapt the HAQ-S into Chinese and then to evaluate its reliability and validity. The Chinese version of the HAQ-S was obtained with a five-step procedure of translation and cross-cultural adaptation. All invited patients met the New York criteria for AS, and a total of 103 patients finally participated in this study. Intraclass correlation coefficient (ICC) was used to evaluate the test-retest and inter-rater reliability of the HAQ-S. Internal consistency of the questionnaire was evaluated by Cronbach’s alpha coefficient. Spearman’s correlation coefficient was calculated to assess the construct validity between the HAQ-S and Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), Bath AS Metrology Index (BASMI), and the laboratory parameters (erythrocyte sedimentation rate, ESR; C-reactive protein, CRP). Test-retest and inter-rater reliability were excellent with intraclass correlation coefficients of 0.987 (p < 0.05) and 0.982 (p < 0.05), respectively. The overall internal consistency of the HAQ-S was found satisfactory (Cronbach’s alpha = 0.914). The Chinese version of the HAQ-S correlated good with the BASFI (r = 0.749, p < 0.01), and moderate with the BASDAI (r = 0.581, p < 0.01) and the BASMI (r = 0.425, p < 0.01). But, the adapted questionnaire correlated poorly with ESR (r = 0.298, p < 0.01) or CRP (r = 0.283, p < 0.01). The Chinese version of the HAQ-S is reliable and valid for the evaluation of Chinese-speaking patients with AS.     

Psychometric properties of the Dutch Five Facet Mindfulness Questionnaire (FFMQ) in patients with fibromyalgia

Mindfulness-based interventions are increasingly being used in clinical populations to reduce psychological distress and improve functioning. The Five Facet Mindfulness Questionnaire (FFMQ) is a questionnaire that measures five facets of mindfulness: observe, describe, actaware, nonjudge and nonreact. The goal of this study was to examine the psychometric properties of the FFMQ in a clinical population of fibromyalgia patients. A total of 141 patients completed an online questionnaire on mindfulness (FFMQ) and theoretically related (e.g. acceptance, openness, alexithymia) and unrelated (physical health) constructs. Thirty-eight patients filled in the FFMQ twice. A confirmatory factor analysis (CFA) was conducted to test the five-factor structure of the FFMQ. Internal consistency and test–retest reliability were respectively assessed with Cronbach’s α and intraclass correlation coefficients. Construct validity was examined by correlating FFMQ facets with theoretically related and unrelated constructs. Incremental validity in predicting mental health and psychological symptoms was examined with regression analyses. CFA confirmed the correlated five-factor structure of the FFMQ. Internal consistency of the five facets was satisfactory and test–retest reliability was good to excellent. Construct validity was excellent, as shown by the moderate to large correlations with related constructs (except observe facet) and weak correlation with a theoretically unrelated construct. Two of the five facets (actaware and nonjudge) had incremental validity over the others in predicting mental health and psychological symptoms. After controlling for related constructs, the actaware facet remained a significant predictor. This study showed satisfactory psychometric properties of the Dutch FFMQ in fibromyalgia patients. The observe facet, however, should be used with caution given its deviant relationship with theoretically related constructs.