A comparative study of outcome in myositis and other musculoskeletal disorders assessed using the Nottingham health profile.

OBJECTIVE: This study evaluated the comparative impact of myositis and other musculoskeletal disorders on general health using the Nottingham health profile (NHP) as a generic measure of health status. METHODS: A prospective observational study of 113 females with myositis, 142 females with rheumatoid arthritis, 45 females with spinal osteoporosis and 96 females with knee osteoarthritis. RESULTS: All mean NHP section scores were higher in myositis and other musculoskeletal disorders compared to population mean values. Section scores for energy and social isolation were high in myositis compared to all other disorders. Scores for physical disability in myositis were similar to RA. Pain scores were higher in RA and OA compared to myositis. Backwards linear regression models explained 26-42% of the variation in energy and social isolation scores. Emotion and physical section scores were the major determinants and the pattern was similar in all disorders. Disease duration and age had little effect. CONCLUSIONS: Myositis is not simply a disease with physical problems but has wide ranging effects on social and emotional well being. Until disease-specific instruments are available, a generic measure like the NHP can be used to assess problems other than muscle pain and loss of strength.

A patient-derived disease activity score can substitute for a physician-derived disease activity score in clinical research.

OBJECTIVE: Joint counts have a central role in assessing disease activity in rheumatoid arthritis (RA). They are usually undertaken by physicians or nurses. We investigated whether joint counts can be devolved to patients and evaluated the use of a patient-derived Disease Activity Score (DAS). METHODS: One hundred RA patients attending a specialist unit were evaluated, comparing joint counts by a physician with patient-assessed joint counts and DAS derived from both methods. They were related to other measures of disease activity in the European League Against Rheumatism (EULAR) core data set and with the Rheumatoid Arthritis Disease Activity Index (RADAI; a validated patient self-assessment index). RESULTS: Regression analysis showed no significant differences between a physician's and patient's joint counts and DAS. There were middle to high correlations between patient and physician assessments of tender joints and swollen joints; using R2, this explained 70% of the variance for tender joints and 40% for swollen joints. Kappa analysis showed good agreement between physician and patient assessments of individual joint tenderness (kappa values 0.49-0.84). There was lower agreement for individual swollen joints (kappa values 0.02-0.61). Physician DAS and patient DAS had a similar correlation with the Health Assessment Questionnaire (HAQ) (r = 0.50 and r = 0.48, respectively). CONCLUSION: The agreements between physician and patient assessments are sufficient to allow patients' assessments to be used for clinical research. This is especially the case with a patient-derived DAS. However, the results are not directly interchangeable and further studies are needed before patients' assessments are used to guide clinical practice.

Techniques for health status measurement in the management of rheumatoid arthritis.

Measuring health status in rheumatoid arthritis is complex, and there are a number of methods available. These range from observed measures of function to broader measures of general health status or quality of life which can be assessed by questionnaires which are completed by the patient or administered by a trained interviewer. The choice of measure depends on the purpose of measurement and the context in which the measurement is being made. Many of the measures available (for example, the SF-36) were developed for use in research and have not been adopted for widespread clinical use. There are, however, some measures, such as the disease repercussion profile, which were developed specifically as clinical tools, or which lend themselves to clinical use by virtue of their ease of completion and their clinical meaningfulness. The choice of method will depend on the purpose of measurement, the question being asked and the instrument the investigator feels most comfortable with.

Early referral and outcome in rheumatoid arthritis.

In a cross-sectional study of 200 outpatients with rheumatoid arthritis (RA) we tested the hypothesis that early specialist referral within one year of disease onset reduces subsequent functional disability. Early referral was defined as being seen in a specialist unit within one year of the onset of symptoms. Functional outcome was measured using the physical functional section of the full test (NHP) and (HAQ). Additional information was collected on other factors likely to influence disability including age, sex, pain scores, and rheumatoid factor positivity. The difference in average HAQ and NHP physical function scores between late and early referrals was 0.34 and 11.0 respectively (p< 0.01 in both cases) using unequal-variance t-test. After adjusting for the other risk factors, multiple regression analysis showed late referral patients had greater NHP physical function scores than early-referred patients by approximately 8 points and there was a similar trend with HAQ. We conclude that early referral for specialist advice is associated with improved health status, with reduced physical function scores on the NHP.

Rheumatoid factor isotypes, disease activity and the outcome of rheumatoid arthritis: comparative effects of different antigens.

The value of rheumatoid factor (RF) isotypes for assessing rheumatoid arthritis (RA) remains debatable. We investigated whether using different antigens to measure RF alters the relationships between RF isotypes and clinical variables. The association between IgA and IgM RF, disease activity, and cumulative anatomical joint damage in RA was studied in 140 patients. The RF isotypes were measured using both rabbit IgG and horse IgG as antigens. Cumulative anatomical damage was assessed radiologically using Larsen's score and disease activity was determined by C-reactive protein (CRP), the health assessment questionnaire (HAQ), and a combined disease activity score (DAS). Patients positive for IgA RF and IgM RF against rabbit IgG had significantly higher disease activity and more radiological damage than negative patients. With horse IgG as antigen these differences were smaller or absent. Patients positive for only IgM RF had milder disease than patients positive for IgA RF with or without IgM RF. The clinical relationships of RF isotypes are related to the antigen used. Measuring IgA RF against rabbit IgG provides most information about disease activity, functional impairment and joint damage.

The radiological assessment of rheumatoid arthritis.

Antirheumatic therapy has changed from a rather conservative approach towards more aggressive early intervention. Objective measures of the course and outcome of rheumatoid arthritis are essential to understand the disease process and evaluate the therapeutic response. Radiological evaluation fulfils many of the criteria of objectivity: the films provide a permanent record and can be evaluated serially and repeatedly; the changes do not fluctuate with disease activity; and good technique and correct timing can keep the radiation load to a very acceptable level. Consequently, therapies can be evaluated on the basis of their efficacy on radiological progression. In clinical practice, a visual qualitative assessment is usually sufficient, but for therapeutic trials or studies of disease progression in certain patient groups, quantitative methods are needed. A number of different evaluation systems have been introduced, but none of these have gained universal acceptance. No ideal evaluation method (which should be rapid, easy to use and have a good level of reproducibility) has yet been found. Here we make provisional recommendations on the conduct of future therapeutic trials to maximise the likelihood that they will give conclusive results using radiographic outcome assessments.

The Nottingham Health Profile as a measure of disease activity and outcome in rheumatoid arthritis.

Clinical measurement in rheumatoid arthritis (RA) has focused on articular problems. Although measures like the Health Assessment Questionnaire (HAQ) are widely used to determine functional impairment, there is a need to determine the overall effect of RA on general health status. We evaluated the relationship of a generic health status measure-the Nottingham Health Profile (NHP)-to the clinical, laboratory and radiological changes in the EULAR core data set for RA. Two hundred consecutive out-patients with RA were recruited. Their mean age was 58.9 yr and mean disease duration 11.3 yr. Patients completed the NHP and the following assessments were made: the EULAR Core Data Set, the duration of morning stiffness, the Disease Activity Score (DAS), rheumatoid factor (RF) levels, and Larsen's score for X-rays of hands and wrists. RA patients had higher scores on the NHP than both a random population sample and a second sample of patients with a variety of common diseases. NHP scores were not related to age or disease duration in RA. There was little relationship between perceived distress and the Larsen score, RF, ESR and C-reactive protein levels. Moderate associations were seen between NHP scores and disease activity measures, including the number of tender and swollen joints, pain and the duration of early morning stiffness, and also with a disability measure-the HAQ. NHP scores were highly related to disease activity measured by DAS. High DAS scores were associated with high scores in the energy level, pain and sleep sections of the NHP. The NHP gives relevant information about RA patients. They have high scores for pain, physical mobility and energy level sections, and also have high distress for sleep and emotional reactions.

Clinical significance of IgA rheumatoid factor subclasses in rheumatoid arthritis.

OBJECTIVE: IgA rheumatoid factor (RF) is associated with greater disease activity and radiological progression in rheumatoid arthritis (RA). We examined whether measuring IgA RF subclasses gives additional clinically relevant information. METHODS: Total IgA RF plus IgA1 RF and IgA2 RF subclasses were estimated by ELISA using rabbit IgG as antigen in 144 patients with established RA. Disease activity was assessed by Disease Activity Score and Health Assessment Questionnaire; the acute phase response was assessed by C-reactive protein levels and joint damage by the Larsen score. RESULTS: Fifty percent of patients had elevated total IgA RF, 60% elevated IgA1 RF, and 50% elevated IgA2 RF. There were significant correlations between total IgA RF and both IgA RF subclasses (p < 0.0001). Measures of disease activity, the acute phase response, and joint damage were all significantly higher (p < 0.001 in each case) in patients with elevated total IgA RF and both IgA RF subclasses compared with RF negative cases. Disease duration influenced the relationship of IgA RF subclasses to joint damage. The Larsen score was only significantly higher in late disease (duration 5 years or more) in both IgA1 RF and IgA2 RF positive patients. CONCLUSION: We found IgA RF positive patients have more aggressive RA than negative cases. Measuring IgA1 RF and IgA2 RF subclasses did not give more information about clinical status than measuring total IgA RF alone.

Clinical and laboratory assessments in rheumatoid arthritis and osteoarthritis.

Clinical and laboratory assessments in rheumatoid arthritis and osteoarthritis precede imaging methods in both defining diagnosis and determining response to therapy. Some assessments are similar in both diseases, e.g. measuring joint pain, the number of involved joints and functional impairment. There are also areas of difference; for example, rheumatoid arthritis is a systemic disease with immune disturbance and positive tests for rheumatoid factor and elevated acute phase markers while osteoarthritis is a more local disease with little systemic upset. In both diseases pain and progressive joint damage result in increasing disability. There is agreement on a core data set in rheumatoid arthritis which comprises: swollen joint counts, tender joint counts, pain assessment, patient's global assessment, an acute phase marker such as the ESR and a self-administered functional questionnaire. There is less agreement on the core data set in osteoarthritis, though pain and functional impairment are both important. Combined or overall indices have been used in both rheumatoid arthritis (e.g. the disease activity score) and in osteoarthritis (e.g. the Lequesne functional index), but there is no general agreement on their value. In both diseases plain radiology is useful to define diagnostic groups and follow progression in long-term studies. Mortality is increased in rheumatoid arthritis and is useful for defining the long term effects of the disease; little is known about mortality in osteoarthritis. Standardizing clinical methods is important and much work is needed in this area.

Joint assessment in rheumatoid arthritis.

Determining the number of swollen joints and tender joints is a key component in the clinical assessment of rheumatoid arthritis (RA). There have been a series of investigations carried out in the last decade, which have defined the best ways to measure joint inflammation and have identified which joints should be evaluated. There is not complete agreement on the optimal joint count, but two approaches are widely used. These comprise counting either 66/68 or 28 joints. The main difference is that the 28-joint count excludes the joints in the feet. Both methods give similar information and are reproducible and valid. Tenderness and swelling should be measured separately. There are advantages and disadvantages associated with using the 28-joint count. It has the benefit of simplicity and takes less time, although some potentially relevant clinical information about the feet may be lost. There is general agreement that grading the severity of individual joint involvement is of limited advantage. Using weighted joint counts is also not widely accepted. Finally there is growing recognition of the need for training in the methods of assessing joints and the importance of international standardization. Joint counts are a component of the core clinical data set for RA and will continue to play a key role in the foreseeable future.