Simplified Disease Activity Index for RA (SDAI)

Assess disease activity in rheumatoid arthritis.

About

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

References

Smolen JS, Breedveld FC, Schiff MH, et. al.

Rheumatology, Volume 42, Issue 2, February 2003, Pages 244–257

The Simplified Disease Activity Index for RA (SDAI) calculator is created by QxMD.
Default Units

1. CRP?

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About

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

References

Smolen JS, Breedveld FC, Schiff MH, et. al.

Rheumatology, Volume 42, Issue 2, February 2003, Pages 244–257

The Simplified Disease Activity Index for RA (SDAI) calculator is created by QxMD.
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