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The Simplified Disease Activity Index (SDAI) and Clinical Disease Activity Index (CDAI) to monitor patients in standard clinical care

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Rheumatoid arthritis (RA) disease activity plays a central role in causing disability both directly and via indirect effects mediated through joint damage, a major sequel of persistent active disease. Evaluation of RA disease activity is therefore important to predict the outcome and effectiveness of therapeutic interventions during follow-up. However, disease activity assessment is among the greatest challenges in the care of patients with RA. We regard measurement of activity as an essential element of following the fate of joint diseases like RA. This evaluation can be facilitated by the use of reduced joint counts and simple indices, such as the Simplified Disease Activity Index (SDAI) and the Clinical Disease Activity Index (CDAI). These scores are validated outcomes for RA and allow the assessment of: actual disease activity, response to therapy, and achievement of particular states such as remission. The simplicity of these scores enables patients to understand the level of their disease activity, as assessed by the rheumatologist, and to correlate increments and decrements of disease activity directly with all aspects of the disease.

Section snippets

The triad and interrelationship of disease activity, joint damage, and functional impairment

Synovitis is the cardinal consequence of the pathogenetic events of inflammatory joint diseases. The type of synovitis encountered by patients with rheumatoid arthritis (RA) contrasts that of other arthritides by its high propensity to destroy bone and cartilage. Although the causes of RA remain enigmatic, some light has been shed on the mechanisms leading to the disease, which comprise – among other events – overexpression of proinflammatory cytokines.1, 2 Surrogates of inflammation include

The central role of disease activity and its evaluation

The central role of disease activity in the triad is based on its direct causation of disability and its elicitation of joint damage, which – indirectly – leads to functional impairment. Thus, control of disease activity is the pivotal therapeutic goal in RA. This has clearly been shown in a multitude of studies, including trials on the effects of various therapies, such as biologic agents16, 17, 18, 19, 20, 21, 22, and investigations aiming at analyzing management strategies23, 24: more

The obstacles to following disease activity

Controlling disease activity by virtue of evaluating its clinical and laboratory characteristics has been a challenge in rheumatology. Reliable evaluation has been possible for about a decade, using the RA core set variables25, 26, 27 and response criteria or indices that reflect improvement on therapeutic intervention or actual disease activity.28, 29, 30 However, it is still not easy to motivate rheumatologists to utilize such methods in routine practice, and even distributing questionnaires

Traditional instruments to evaluate disease activity and its improvement

Over the decades, numerous scores or response criteria have been developed to evaluate disease activity at a single time point or (absolute or relative) improvement of disease activity.32 In the 1990s, the American College of Rheumatology (ACR) developed response criteria28 based on the improvement of the ACR Core Data Set variables. These were designed to differentiate between active treatment and placebo in clinical trials. The criteria have limitations in clinical practice because they

SDAI and CDAI

After nearly a decade, a new generation of scores has been developed, in line with current insights about the importance of close monitoring of patients and the value of active involvement of patients in the process of controlling disease activity in other fields of medicine.39, 40 Major limitations with the earlier scoring systems were the complexity of the then-available indices, such as those based on the DAS, which were obstacles to effective patient involvement and consequential clinical

Summary

Evaluation of disease activity in RA is not trivial. No single marker can reflect all aspects of the disease. Disease activity instruments – such as scores, criteria, and indices – have significantly improved the ability of the rheumatologist to evaluate the course of RA. All that is required is the performance of formal joint counts, which is not an unreasonable requirement for physicians dealing with joint diseases. Reduced joint counts, which are highly reliable, facilitate joint assessment

References (60)

  • M.A. van Leeuwen et al.

    Interrelationship of outcome measures and process variables in early rheumatoid arthritis. A comparison of radiologic damage, physical disability, joint counts, and acute phase reactants

    Journal of Rheumatology

    (1994 Mar)
  • T. Pincus et al.

    Severe functional declines, work disability, and increased mortality in seventy-five rheumatoid arthritis patients studied over nine years

    Arthritis and Rheumatism

    (1984)
  • T. Sokka et al.

    Work disability in rheumatoid arthritis 10 years after the diagnosis

    Journal of Rheumatology

    (1999 Aug)
  • T. Pincus et al.

    Early mortality in RA predicted by poor clinical status

    Bulletin on the Rheumatic Diseases

    (1992)
  • D. Aletaha et al.

    Measuring function in rheumatoid arthritis: identifying reversible and irreversible components

    Arthritis and Rheumatism

    (2006)
  • K.W. Drossaers-Bakker et al.

    Long-term course and outcome of functional capacity in rheumatoid arthritis: the effect of disease activity and radiologic damage over time

    Arthritis and Rheumatism

    (1999)
  • P.M. Welsing et al.

    The relationship between disease activity, joint destruction, and functional capacity over the course of rheumatoid arthritis

    Arthritis and Rheumatism

    (2001 Sep)
  • J.S. Smolen et al.

    Evidence of Radiographic Benefit of Infliximab Plus Methotrexate in Rheumatoid Arthritis Patients Who Had No Clinical Improvement: A Detailed Subanalysis of the ATTRACT Trial

    Arthritis and Rheumatism

    (2005)
  • F.C. Breedveld et al.

    The PREMIER study - A multicenter, randomized, double-blind clinical trial of combination therapy with adalimumab plus methotrexate versus methotrexate alone or adalimumab alone in patients with early, aggressive rheumatoid arthritis who had not had previous methotrexate treatment

    Arthritis and Rheumatism

    (2006)
  • E.C. Keystone et al.

    Radiographic, clinical, and functional outcomes of treatment with adalimumab (a human anti-tumor necrosis factor monoclonal antibody) in patients with active rheumatoid arthritis receiving concomitant methotrexate therapy: a randomized, placebo-controlled, 52-week trial

    Arthritis and Rheumatism

    (2004)
  • P.E. Lipsky et al.

    Infliximab and methotrexate in the treatment of rheumatoid arthritis. Anti-Tumor Necrosis Factor Trial in Rheumatoid Arthritis with Concomitant Therapy Study Group

    New England Journal of Medicine

    (2000 Nov 30)
  • E.W. St Clair et al.

    Combination of infliximab and methotrexate therapy for early rheumatoid arthritis: a randomized controlled trial

    Arthritis and Rheumatism

    (2004)
  • S. Cohen et al.

    Rituximab for rheumatoid arthritis refractory to anti-tumor necrosis factor therapy

    Arthritis and Rheumatism

    (2006)
  • J.M. Kremer et al.

    Effects of abatacept in patients with methotrexate-resistant active rheumatoid arthritis: a randomized trial

    Annals of Internal Medicine

    (2006 Jun 20)
  • Y.P. Goekoop-Ruiterman et al.

    Clinical and radiographic outcomes of four different treatment strategies in patients with early rheumatoid arthritis (the BeSt study): a randomized, controlled trial

    Arthritis and Rheumatism

    (2005)
  • M. Boers et al.

    WHO and ILAR core endpoints for symptom modifying antirheumatic drugs in RA clinical trials

    Journal of Rheumatology

    (1994)
  • D.T. Felson et al.

    The American College of Rheumatology preliminary core set of disease activity measures for rheumatoid arthritis clinical trials

    Arthritis and Rheumatism

    (1993)
  • D.L. Scott et al.

    Disease activity in rheumatoid arthritis -preliminary report of the Consensus Study Group of the European Workshop for Rheumatology Research

    Clinical and Experimental Rheumatology

    (1992)
  • D.T. Felson et al.

    American College of Rheumatology preliminary definition of improvement in rheumatoid arthritis

    Arthritis and Rheumatism

    (1995)
  • D.M.F.M. Van der Heijde et al.

    Development of a Disease activity score based on judgement in clinical practice by rheumatologists

    Journal of Rheumatology

    (1993)
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