Simplified Disease Activity Index for RA (SDAI)
Assess disease activity in rheumatoid arthritis.
28 joints are assessed, including: <br /> <br /> Shoulders, Elbows, Knees <br /> In the hands: first through fifth metacarpophalangeal joint, the interphalangeal joint of the thumb, and the second through fifth proximal interphalangeal joint.
28 joints are assessed, including: <br /> <br /> Shoulders, Elbows, Knees <br /> In the hands: first through fifth metacarpophalangeal joint, the interphalangeal joint of the thumb, and the second through fifth proximal interphalangeal joint.
The PGA or Patient Global disease Activity estimate represents the patient's self assessment of disease activity on a <strong>0-10 scale</strong> where 10 means maximal activity.
The EGA or Evaluator Global disease Activity estimate represents the evaluator's assessment of disease activity on a <strong>0-10 scale</strong> where 10 means maximal activity.
The Simplified Disease Activity Index for Rheumatoid Arthritis (SDAI) is a scoring system that has been validated in both research and clinical settings. It has been shown to have the highest sensitivity and specificity for predicting a physicians' decisions to change DMARD therapy when compared to other scores.
In an observational study, a score ≥15 had the best combination of sensitivity (90%) and specificity (86%) when compared to a clinical decision to change DMARDs because of inadequate control of disease. Remission is defined as an SDAI of <3.3, low disease activity as ≤11, moderate disease activity as ≤26 and high disease activity as >26.
Response to therapy is considered moderate if SDAI decreases by ≥7 and major if decreases by ≥17
SDAI is calculated as follows:
- SDAI = SJC + TJC +PGA + EGA + CRP
Where:
- SJC = Swollen Joint Count
- TJC = Tender Joint Count
- PGA = Patient Global Assessment of Disease Activity
- EGA = Evaluator Global Assessment of Disease Activity
- CRP = CRP in mg/dL
- [1]Smolen JS, Breedveld FC, Schiff MH, et. al.: A simplified disease activity index for rheumatoid arthritis for use in clinical practice.Rheumatology, Volume 42, Issue 2, February 2003, Pages 244–257
- [2]Soubrier M et al.: Which variables best predict change in rheumatoid arthritis therapy in daily clinical practice?Journal of Rheumatology 2006, 33 (7): 1243-6
Results
Real-time automated computation
The Simplified Disease Activity Index for Rheumatoid Arthritis (SDAI) is a scoring system that has been validated in both research and clinical settings. It has been shown to have the highest sensitivity and specificity for predicting a physicians' decisions to change DMARD therapy when compared to other scores.
In an observational study, a score ≥15 had the best combination of sensitivity (90%) and specificity (86%) when compared to a clinical decision to change DMARDs because of inadequate control of disease. Remission is defined as an SDAI of <3.3, low disease activity as ≤11, moderate disease activity as ≤26 and high disease activity as >26.
Response to therapy is considered moderate if SDAI decreases by ≥7 and major if decreases by ≥17
SDAI is calculated as follows:
- SDAI = SJC + TJC +PGA + EGA + CRP
Where:
- SJC = Swollen Joint Count
- TJC = Tender Joint Count
- PGA = Patient Global Assessment of Disease Activity
- EGA = Evaluator Global Assessment of Disease Activity
- CRP = CRP in mg/dL
- [1]Smolen JS, Breedveld FC, Schiff MH, et. al.: A simplified disease activity index for rheumatoid arthritis for use in clinical practice.Rheumatology, Volume 42, Issue 2, February 2003, Pages 244–257
- [2]Soubrier M et al.: Which variables best predict change in rheumatoid arthritis therapy in daily clinical practice?Journal of Rheumatology 2006, 33 (7): 1243-6