Quantitative measures for assessing rheumatoid arthritis in clinical trials and clinical care

Reporting of radiographic methods in randomised controlled trials assessing structural outcomes in rheumatoid arthritis

BACKGROUND

Because an increasing number of clinical trials evaluating disease-modifying antirheumatic drugs in rheumatoid arthritis (RA) emphasise radiographic outcomes as a primary outcome, using a reproducible radiographic measure should be placed at a premium.

AIM

To evaluate the reporting of radiographic methods in randomised trials assessing radiographic outcomes in RA.

METHODS

Medline was searched for randomised controlled trials assessing radiographic outcomes published between January 1994 and December 2005 in general medical and specialty journals with a high impact factor. One reader extracted data (radiographic acquisition, assessment and reproducibility) using a standardised form.

RESULTS

A total of 46 reports were included in the analysis. The mean (SD) methodological quality scores on the Jadad scale (range 0-5) and the Delphi list (0-9) were 2.9 (1.2) and 6.4 (1.3), respectively. Use of a standardised procedure for the acquisition of the radiographs was reported in 2 (4.3%) articles. 2 (4.3%) reports indicated that the quality of the radiographs was evaluated. In 65.2% of the reports, > or = 2 radiographic scores were used. Reporting of radiographic assessment was well detailed for number of readers (91.3%), information on readers (71.7%), blinding (91.4%) and how films were viewed (74.0%). The reproducibility of the reading was reported in 39.1% of the articles.

CONCLUSION

The reporting of results of randomised controlled trials of radiographic outcomes in RA shows great variability in radiographic scores used. Reporting of radiographic methods could be improved upon, especially the acquisition procedure and the reproducibility of the reading.

Comment on the use of self-reporting instruments to assess patients with rheumatoid arthritis: the longitudinal association between the DAS28 and the VAS general health

OBJECTIVE

Recently, the use of patient self-reporting instruments instead of clinical, objective measurements to assess rheumatoid arthritis (RA) patients was proposed. This assumes a constant association between disease activity and the self-reporting instruments. The objective was to explore the association (in time) between disease activity and patient perception of general health, disease activity, pain, and functional disability in patients with RA.

METHODS

Data of 624 newly diagnosed RA patients who completed 3 years of followup were analyzed. Cross-sectional linear regression models and longitudinal regression models were estimated, with a visual analog scale (VAS) measuring general health (VAS-GH; 0 = best, 100 = worst) as a dependent variable and the Disease Activity Score (DAS28) without the VAS-GH as an independent variable. Other dependent variables were VAS disease activity, pain, and the Health Assessment Questionnaire.

RESULTS

The DAS28 and VAS-GH were significantly associated in RA patients (P < 0.001). However, the explained variance was low (6.7%). From diagnosis to 3 years after the diagnosis, the intercept decreased given the same regression coefficient. The longitudinal regression model showed that the VAS-GH improved during disease course independent of a change in DAS28. Analyses on the other outcome parameters showed similar results.

CONCLUSION

Patients' perception of health can be different with equal disease activity, depending on the moment in the disease course. Furthermore, our results indicate that self-reported measures on functionality, disease activity, and general health cannot substitute for objective measures of disease activity in RA in longitudinal studies; subsequently, both need to be measured.

Modelling the effect of function and disease activity on costs and quality of life in rheumatoid arthritis

OBJECTIVE

When treatments with the potential to change the natural history of a disease are introduced, their longer-term effect on costs and quality of life (utility) has to be estimated using economic models. However, to remain useful tools, models must be updated when new information becomes available. Our earlier models in rheumatoid arthritis (RA) have been based on functional status, but it has recently been shown that disease activity might have an independent effect on utility. The objective of this study was to improve the model by incorporating the effect of a subjective measure of disease severity and activity (global VAS).

METHODS

A Markov model was constructed with five states according to functional status (HAQ), and each state was subdivided according to the VAS (<40 and >40). Disease development (transition probabilities between the states) was taken from a longitudinal cohort study of patients with early RA in Sweden. A recent population-based survey of 616 patients with RA provided data on costs and utilities. The model incorporates the full distribution of costs and utilities from the survey, and long-term projections are made using Monte Carlo simulation.

RESULTS

The global VAS had a highly significant effect on utilities independently of HAQ. For resource consumption, only HAQ was a significant predictor, with the exception of sick leave, which was correlated with the VAS but not with HAQ. Using the cohort distribution from the longitudinal study, expected mean costs per patient over 10 yr were 106 034 euros (s.d. 5091 euros) (1 euro = SEK 9.20) and the expected number of quality-adjusted life years (QALYs) was 5.08 (s.d. 0.09). Patients starting at HAQ <0.6 but with consistently high VAS scores would have expected costs of 102 830 euros and 4.96 QALYs, while patients with low VAS scores would have costs of 81 603 euros and 6.01 QALYs.

CONCLUSION

Our new model incorporates for the first time the effect of a subjective measure of disease severity and activity on both costs and utility, making it a sensitive tool to estimate the cost-effectiveness of disease-modifying treatments. New data on resource consumption indicate a shift to higher direct costs, particularly in early disease, and lower indirect costs in more advanced disease. The large size of the data sets used in this model reduces the uncertainty and makes estimates very stable.

Physical examination and laboratory tests in the management of patients with rheumatoid arthritis: development of recommendations for clinical practice based on published evidence and expert opinion

OBJECTIVES

To develop recommendations for the physical and laboratory-test follow-up of patients with rheumatoid arthritis (RA) seen in everyday practice, using evidence from the literature, supplemented with expert opinion when needed.

METHODS

A scientific committee selected 7-10 questions using the Delphi consensus procedure. Evidence-based responses to each question were sought in the literature and were then used by a panel to develop recommendations. To fill in gaps in knowledge from the literature, the panelists relied on their personal opinion.

RESULTS

The seven questions dealt with the physical and laboratory-test follow-up of RA and the factors predicting disease severity. The literature review identified 799 articles whose title and abstract suggested relevance to the study. Elimination of articles that provided no data on the study topic left 128 original articles. The panel developed seven recommendations, one for each question, which were accepted by consensus.

CONCLUSION

Recommendations about the physical and laboratory-test follow-up of patients with RA seen in everyday practice were developed. Because they constitute an objective foundation built by consensus among experts, should improve the uniformity and quality of care provided to RA patients in everyday practice.

Responsiveness of the electronic touch screen WOMAC 3.1 OA Index in a short term clinical trial with rofecoxib

BACKGROUND

The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index is a self-administered validated questionnaire for patients with osteoarthritis (OA) of the hip or knee. The electronic touch screen version of the WOMAC (e-WOMAC) has been previously shown to be highly correlated with the original paper format. However, whether the e-WOMAC would be suitable for monitoring the effects of drug treatment is unknown.

AIM

To validate the longitudinal use of the e-WOMAC questionnaire and its ability to detect changes in WOMAC-scores induced by drug treatment in outpatient care.

METHODS

Fifty-three outpatients, men and women (mean age: 64 years; SD+/-9.5), with symptomatic osteoarthritis of hip or knee were included in an open label study with rofecoxib. At three visits over 3 weeks, responsiveness of the WOMAC 3.1 regarding the three subscales, pain, stiffness and function, were compared for the original paper format and the computer touch screen format (QUALITOUCH) using a Likert scale. WOMAC scores were transformed to the 0-100 scale. ANOVA for repeated measures was used for analysis and effect sizes by subscale were compared for both formats.

RESULTS

Responsiveness for all three subscales was similar between formats. In both formats, pain and stiffness were significantly reduced with rofecoxib as early as 7 days, while functional ability was significantly increased (P<0.01 for all aggregate subscale scores) with continuing improvement until the end of study. The effect sizes by subscale between Day 1 and 21 were not statistically different between the paper and the electronic version of the questionnaire and showed similar clinically meaningful improvements in WOMAC scores over 3 weeks.

CONCLUSION

In this longitudinal intervention study, the e-WOMAC OA Index 3.1 showed similar responsiveness in detecting clinically meaningful changes than the original paper format.

The impact of low family income on self-reported health outcomes in patients with rheumatoid arthritis within a publicly funded health-care environment †† Presented in part as a poster at the International Society of Quality of Life Research Annual Meeting in Prague, Czech Republic, November 2003

OBJECTIVE

Self-rated health (SRH) is an independent, strong predictor of morbidity and mortality. Socio-economic status (SES) is strongly associated with SRH. This study investigated the relationship between SES and SRH outcomes in a sample of patients with rheumatoid arthritis (RA) in Canada.

METHODS

Both generic preference-based [Health Utilities Index Mark 3 (HUI3) and Short Form 6D (SF-6D)] and non-preference-based [disease-specific (Rheumatoid Arthritis Quality of Life, RAQoL) and a functional status (Health Assessment Questionnaire, HAQ)] SRH questionnaires were administered to 313 RA patients. Both proximate (education and annual household income) and contextual (neighbourhood income, education and unemployment) measures of SES were captured. Ordinary least squares (OLS) regression was used to adjust for RA severity while assessing the relationship between SRH and SES measures. Two-stage least-squares (TSLS) regression was used to determine if there was an inter-relationship between SES and SRH measures.

RESULTS

The sample was well distributed across RA severity and SES measures. Contextual and proximate measures of SES were poorly correlated. Lower levels of proximate SES measures (but not contextual) were associated with poorer SRH outcomes. The OLS regressions showed significant associations between the HUI3 and the SF-6D overall scores and the HAQ for self-reported income. The RAQoL did not differ significantly across SES. TSLS regression confirmed the finding that self-reported income was similarly associated with the SRH measures.

CONCLUSIONS

Even in a country with universal access to health-care, the impact of a chronic disease such as RA on SRH is associated with self-reported income. The finding that preference-based measures vary with income independently of RA severity could bias economic evaluation.

Pain and joint mobility explain individual subdimensions of the health assessment questionnaire (HAQ) disability index in patients with rheumatoid arthritis

OBJECTIVE

To explore the associations between individual subdimensions of the health assessment questionnaire (HAQ) and clinical variables in patients with rheumatoid arthritis.

METHODS

304 patients with rheumatoid arthritis (73% female, mean (SD) age, 58 (13) years; disease duration 6 (9) years, 69% rheumatoid factor positive) completed the HAQ for functional capacity (0-3) and a 100 mm visual analogue scale for pain. Grip strength, range of motion of the large joints, Larsen score for radiographic damage of hand and foot joints, and the number of tender and swollen joints were recorded. A logit regression model was used to study associations between subdimensions of the HAQ and other variables.

RESULTS

Mean (range) total HAQ score was 0.92 (0 to 2.88) and varied from 0.73 to 1.04 in the subdimensions. Disability was lowest in the "walking" and highest in the "reach" subdimension. Pain was an explanatory variable in all individual subdimensions. Decreased grip strength, limitation of shoulder and wrist motion, and a larger number of swollen and tender joints in the upper extremities were related to several subdimensions. A higher pain score and swollen joint count in the upper extremities, decreased grip strength, and limited motion of wrist, shoulder, and knee joints explained increased disability (higher total HAQ scores).

CONCLUSIONS

In patients with rheumatoid arthritis, pain and range of movements of joints have the greatest impact on individual subdimensions of the HAQ. Extent of radiographic damage in peripheral joints and the number of swollen and tender joints are of lesser importance for function.