The formula to calculate the Clinical Disease Activity Index (CDAI) is:
\[ CDAI = (TJC \times 0.56) + (SJC \times 0.28) + (PGA \times 0.014) + (EGA \times 0.014) \]
Where:
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.
Let's say the Tender Joint Count (TJC) is 10, the Swollen Joint Count (SJC) is 5, the Patient's Global Assessment (PGA) is 7, and the Evaluator's Global Assessment (EGA) is 6. Using the formula:
\[ CDAI = (10 \times 0.56) + (5 \times 0.28) + (7 \times 0.014) + (6 \times 0.014) = 7.98 \]
So, the Clinical Disease Activity Index (CDAI) is 7.98.