Targeting disease remission has socio-economic benefits over low disease activity

Achieving disease remission in patients with rheumatoid arthritis (RA) provides superior outcomes across measures of socio-economic importance including work productivity and quality of life according to results presented today at EULAR 2010, the Annual Congress of the European League Against Rheumatism in Rome, Italy. These Austrian findings are reported in addition to improvements in measures of physical functioning, when compared with RA patients achieving low disease activity (LDA).

Results from this cross-sectional study of 356 patients showed statistically significant differences (p= < 0.01) between ra patients who had achieved disease remission (rem, defined by the clinical disease activity index (cdai), a composite index including objective and patient derived scores) compared to those who had achieved lda across several domains including:

• Effect on work productivity, based on results of the Work Productivity and Activity Impairment (WPAI*) index: impairment while working 11.3% vs. 27.2%, overall activity impairment 18.1% vs. 33.8%, REM vs LDA respectively
  
• Impact on quality of life, based on results of the Euro Qol (5D EQ-5D)* index: 0.89 vs. 0.78 and the SF-36 PCS* index: 46.2 vs. 37.8
  
• Impact on physical functioning, based on results of the Health Assessment Questionnaire (HAQ*) scores: 0.38 vs. 0.75.

"We know that RA as a chronic disease often has a long term impact on patients' functional ability, affecting not only patients' well-being but also their working lives. The majority of those affected report a loss of productivity at work, and many even have to stop work altogether," said Dr. Helga Radner, Department of Rheumatology, Medical University Vienna, Austria and lead author of the study. "Our study results show that the benefits of achieving clinical remission are worthwhile, especially from a socio-economic point of view, as it decreases the 'burden of disease' not only for patients but also for society on a wider scale. The findings reveal that remission is even superior to an almost perfect disease activity state, namely low disease activity, therefore our major task in treating RA-patients should be its achievement and maintenance"

Interestingly, researchers found that the emotional aspects of the disease activity measures were similarly reported in patients in remission and in low disease activity indicating that once disease activity or symptom levels are reduced to a certain level, emotional discord may stabilise.

Longitudinal analysis over one year showed significant improvements when comparing the two patient populations in the following areas:

• Quality of life (EQ-5D); 0.89 vs. 0.80 (REM vs. LDA respectively), p < 0.001
  
• Percent of overall activity impairment (WPAI) per year; 12.2% vs. 31.0%, p < 0.001
  
• Physical disability (HAQ); 0.23 vs. 0.69, p= < 0.001

Significant differences between REM and LDA were not seen in the domain of percentage impairment while working (8.3% vs. 20.0% (REM vs. LDA respectively), p=0.096).

This study of 356 patients registered at the Department of Rheumatology at the Medical University of Vienna involved one cross sectional analysis (at a single time point) of RA patients, with 34 patients achieving REM (CDAI ≤2.8) and 66 patients achieving LDA (2.8≤CDAI<1).

* HAQ is a disability index used by physicians to measure an individual's physical functioning and assesses ability to undertake everyday activities such as dressing, eating and walking, and whether assistance from another person or disability aids is required. A higher score indicates greater disability.

The WPAI questionnaire measures work time missed and work and activity impairment due to a specified health problem during the last 7 days.

The (EQ-5D) is a health-related quality of life scale consisting of five dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) to which responses can be made at three levels of severity (no problems/some or moderate problems/extreme problems).

The Short Form 36 (SF36) SF-36 is a multi-purpose health survey which yields an 8-scale profile of functional health and well-being scores as well as psychometrically-based physical and mental health summary measures.

The Clinical Disease Activity Index allows the assessment of actual disease activity, response to therapy, and achievement of particular states such as remission. The simplicity of the scoring system facilitates patient understanding of the level of their disease activity.