Enter the Tender Joint Count, Swollen Joint Count, Patient’s Global Assessment, and Evaluator’s Global Assessment into the calculator to determine the Clinical Disease Activity Index.

Cdai (Clinical Disease Activity Index) Formula

The following formula is used to calculate the Clinical Disease Activity Index (CDAI).

CDAI = (TJC * 0.56) + (SJC * 0.28) + (PGA * 0.014) + (EGA * 0.014)

Variables:

  • CDAI is the Clinical Disease Activity Index
  • TJC is the Tender Joint Count
  • SJC is the Swollen Joint Count
  • PGA is the Patient’s Global Assessment of disease activity (0-10 scale)
  • EGA is the Evaluator’s Global Assessment of disease activity (0-10 scale)

To calculate the Clinical Disease Activity Index, multiply the Tender Joint Count by 0.56, the Swollen Joint Count by 0.28, the Patient’s Global Assessment by 0.014, and the Evaluator’s Global Assessment by 0.014. Add all these results together to get the CDAI.

What is a Cdai (Clinical Disease Activity Index)?

The Clinical Disease Activity Index (CDAI) is a tool used by healthcare professionals to measure disease activity in patients with rheumatoid arthritis. It assesses the number of swollen and tender joints, along with the patient’s and physician’s global assessment of disease activity. The CDAI provides a numerical score that helps in tracking the disease progression and the effectiveness of treatment over time. It does not require laboratory tests, making it a practical tool for clinical settings.

How to Calculate Cdai (Clinical Disease Activity Index)?

The following steps outline how to calculate the Clinical Disease Activity Index (CDAI).

  1. First, determine the value of the Tender Joint Count (TJC).
  2. Next, determine the value of the Swollen Joint Count (SJC).
  3. Next, determine the value of the Patient’s Global Assessment of disease activity (PGA) on a scale of 0-10.
  4. Next, determine the value of the Evaluator’s Global Assessment of disease activity (EGA) on a scale of 0-10.
  5. Using the formula CDAI = (TJC * 0.56) + (SJC * 0.28) + (PGA * 0.014) + (EGA * 0.014), calculate the Clinical Disease Activity Index (CDAI).
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Tender Joint Count (TJC) = 5

Swollen Joint Count (SJC) = 3

Patient’s Global Assessment (PGA) = 7

Evaluator’s Global Assessment (EGA) = 6