The CDAI (Clinical Disease Activity Index) Calculator is a useful tool for evaluating rheumatoid arthritis (RA) disease activity. It helps healthcare professionals assess inflammation and disease severity quickly.
Formula
The formula to calculate CDAI is:
CDAI = (TJC * 0.56) + (SJC * 0.28) + (PGA * 0.014) + (EGA * 0.014)
Where:
- TJC = Tender Joint Count
- SJC = Swollen Joint Count
- PGA = Patient Global Assessment
- EGA = Evaluator Global Assessment
How to Use
- Enter the Tender Joint Count (TJC) and Swollen Joint Count (SJC).
- Input the Patient Global Assessment (PGA) and Evaluator Global Assessment (EGA).
- Click “Calculate” to get the CDAI score.
Example
If a patient has:
- TJC = 10
- SJC = 8
- PGA = 40
- EGA = 30
The calculation would be:
CDAI = (10 * 0.56) + (8 * 0.28) + (40 * 0.014) + (30 * 0.014) = 8.54
FAQs
- What is the CDAI Calculator used for?
It is used to assess rheumatoid arthritis disease activity. - How accurate is the CDAI score?
CDAI is a clinically validated method to measure RA activity. - Can patients use this calculator at home?
Yes, but a healthcare provider should interpret the results. - What is a normal CDAI score?
A score below 2.8 indicates remission. - What does a high CDAI score indicate?
A high score suggests moderate to severe disease activity. - What are the CDAI score ranges?
- Remission: ≤2.8
- Low Activity: 2.9 – 10
- Moderate Activity: 10.1 – 22
- High Activity: >22
- How does CDAI compare to DAS28?
CDAI does not require lab tests, while DAS28 includes ESR/CRP levels. - Can CDAI be used for other diseases?
It is specific to rheumatoid arthritis. - Is the CDAI calculation affected by medications?
No, but medications influence the disease activity level. - Does CDAI consider lab results?
No, CDAI is a purely clinical measure. - Can CDAI help monitor treatment effectiveness?
Yes, tracking CDAI over time helps assess progress. - Who developed the CDAI method?
It was developed by rheumatologists as a simplified RA assessment tool. - How often should CDAI be measured?
It is typically measured at each clinical visit. - Can CDAI be calculated manually?
Yes, using the formula, but a calculator simplifies the process. - What if my CDAI score is borderline?
Your doctor may suggest lifestyle changes or medication adjustments. - Are there any alternatives to CDAI?
Other methods include DAS28 and SDAI (Simplified Disease Activity Index). - Is CDAI used globally?
Yes, it is widely used in rheumatology clinics worldwide. - Does physical therapy affect the CDAI score?
It can help reduce joint counts, lowering the CDAI score over time. - Can stress affect my CDAI score?
Yes, stress can impact perceived pain and assessment scores. - What should I do if my CDAI score is high?
Consult your doctor for treatment options and lifestyle modifications.
Conclusion
The CDAI Calculator is a quick and effective tool for assessing rheumatoid arthritis activity. By tracking joint counts and patient assessments, it helps in making informed treatment decisions.