Validity of single variables and composite indices for measuring disease activity in rheumatoid arthritis.

There is no agreement as to which variable best mirrors disease activity in rheumatoid arthritis (RA) and no studies have been performed on the validity of disease activity variables. In this study the validity of 10 commonly used single variables and three composite indices was tested. All patients participated in a large follow up study in two clinics. The patients (n = 233) had classical or definite RA and a disease duration of less than one year at entry. The mean follow up time was 30 months; the follow up frequency was once every four weeks; 6011 records were used in the analysis. The validation criteria included correlations with the other variables (correlational validity), with the physical disability (criterion validity I), and with the radiographically determined damage of hands and feet (construct validity). The judgment of a group of rheumatologists in clinical practice was also used as a model of criterion validity (II). In this comparison the disease activity score and Mallya index showed the best validity. The best single variable was the number of swollen joints. The validity of most single variables was poor and these variables were not suitable as single endpoint measures in clinical trials.

[1]  M. A. van 't Hof,et al.  Judging disease activity in clinical practice in rheumatoid arthritis: first step in the development of a disease activity score. , 1990, Annals of the rheumatic diseases.

[2]  H. Holman,et al.  Measurement of patient outcome in arthritis. , 1980, Arthritis and rheumatism.

[3]  D. Heijde,et al.  EFFECTS OF HYDROXYCHLOROQUINE AND SULPHASALAZINE ON PROGRESSION OF JOINT DAMAGE IN RHEUMATOID ARTHRITIS , 1989, The Lancet.

[4]  W. Buchanan,et al.  Clinical studies with an articular index for the assessment of joint tenderness in patients with rheumatoid arthritis. , 1968, The Quarterly journal of medicine.

[5]  D M Chaput de Saintonge,et al.  Clinical judgment in rheumatoid arthritis. I. Rheumatologists' opinions and the development of 'paper patients'. , 1983, Annals of the rheumatic diseases.

[6]  J. Sharp.  Radiologic assessment as an outcome measure in rheumatoid arthritis. , 1989, Arthritis and rheumatism.

[7]  J. Sharp,et al.  Clinical responses during gold therapy for rheumatoid arthritis. Changes in synovitis, radiologically detectable erosive lesions, serum proteins, and serologic abnormalities. , 1982, Arthritis and rheumatism.

[8]  P Tugwell,et al.  Preference for endpoint measures in clinical trials: results of structured workshops. , 1982, The Journal of rheumatology.

[9]  P. Halberg,et al.  Clinical synovitis and radiological lesions in rheumatoid arthritis. A prospective study of 25 patients during treatment with remission-inducing drugs. , 1983, Scandinavian journal of rheumatology.

[10]  C. Joyce,et al.  Inability of rheumatologists to describe their true policies for assessing rheumatoid arthritis. , 1986, Annals of the rheumatic diseases.

[11]  P. van Riel,et al.  Sensitivity of a Dutch Health Assessment Questionnaire in a Trial Comparing Hydroxychloroquine vs. Sulphasalazine , 1990 .

[12]  R. Mallya,et al.  The assessment of disease activity in rheumatoid arthritis using a multivariate analysis. , 1981, Rheumatology and rehabilitation.

[13]  T. Spector,et al.  What should we hope to achieve when treating rheumatoid arthritis? , 1989, Annals of the rheumatic diseases.

[14]  A. Silman,et al.  Articular indices of joint inflammation in rheumatoid arthritis. Correlation with the acute-phase response. , 1987, Arthritis and rheumatism.

[15]  J. Stuart,et al.  EFFICACY OF TESTS USED TO MONITOR RHEUMATOID ARTHRITIS , 1989, The Lancet.

[16]  H K Genant,et al.  How many joints in the hands and wrists should be included in a score of radiologic abnormalities used to assess rheumatoid arthritis? , 1985, Arthritis and rheumatism.

[17]  P. Tugwell,et al.  A methodologic framework for developing and selecting endpoints in clinical trials. , 1982, The Journal of rheumatology.

[18]  J. Stuart,et al.  RANKING OF LABORATORY TESTS BY CONSENSUS ANALYSIS , 1986, The Lancet.