SDAI Calculator

Simple Disease Activity Index for Rheumatoid Arthritis

Calculate SDAI Score

Tender Joint Count(0-28 joints)

Swollen Joint Count(0-28 joints)

C-Reactive Protein (CRP)(0-200 mg/dL)

Patient Global Assessment(0-10 scale)

Considering all the ways arthritis affects you, how well are you doing?

0 = Very Well10 = Very Poorly

Provider Global Assessment(0-10 scale)

Disease Activity Classification

0 = No Activity10 = Maximum Activity

Formula

SDAI = Tender Joint Count + Swollen Joint Count + CRP (mg/dL) + Patient Global Activity + Provider Global Activity

Enter all values to calculate SDAI score

When to Use

•All patients with rheumatoid arthritis
•Reassessing patients after initiating new RA medications

Why Use SDAI

•The Simplidied Disease Activity Index (SDAI) provides an excellent overview of a patient's disease severity (it correlates closely with the CDAI which does not require laboratory data) and the DAS-28.
•The SDAI can also help guide therapy based on severity of disease.

Clinical Context

The Simple Disease Activity Index (SDAI) is a validated composite score used to assess disease activity in rheumatoid arthritis patients.

It combines objective clinical findings (tender and swollen joint counts), laboratory inflammation markers (CRP), and subjective assessments from both the patient and healthcare provider.

This calculator is intended for clinical decision support and should be used in conjunction with professional medical judgment.