Rheumatoid Arthritis Severity Scale

The assessment of rheumatoid arthritis (RA) severity involves a comprehensive evaluation of various clinical parameters. The most commonly used tool for assessing RA severity is the Disease Activity Score (DAS), specifically DAS28 (Disease Activity Score using 28 joint counts). This score incorporates several measures to assess disease activity and severity.

Here is a detailed breakdown of the components involved in the DAS28 and how they are measured:

Tender Joint Count (TJC):
Description: The TJC involves counting the number of joints that are tender or painful upon palpation or movement.
Measurement: A healthcare provider physically examines 28 joints (including shoulders, elbows, wrists, knuckles, hips, knees, and ankles) and notes which joints are tender. The number of tender joints is recorded.

Swollen Joint Count (SJC):
Description: The SJC assesses the number of joints that are swollen due to inflammation.
Measurement: Similar to the TJC, a healthcare provider examines the same 28 joints to identify which joints are visibly swollen. The count of swollen joints is documented.

Acute Phase Reactants (e.g., C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR)):
Description: These are blood tests that measure inflammatory markers in the body, indicating the level of systemic inflammation.
Measurement: Blood samples are taken to measure the levels of CRP or ESR. Elevated levels suggest active inflammation.

Patient Global Assessment of Disease Activity:
Description: This involves asking the patient to subjectively rate their overall disease activity and how they feel their RA is affecting them.
Measurement: Patients may rate their disease activity on a scale (e.g., 0-10), where 0 indicates no disease activity and 10 represents maximum disease activity.

The DAS28 formula combines these components to calculate an overall disease activity score:

DAS28=0.56×TJC+0.28×SJC+0.70×log⁡(CRP)+0.014×Patient Global AssessmentDAS28=0.56×TJC
​+0.28×SJC

​+0.70×log(CRP)+0.014×Patient Global Assessment

The TJC and SJC contribute to the joint examination portion of the score.
The CRP (or ESR) value reflects the acute phase reactants.
The Patient Global Assessment provides the patient’s perspective on disease activity.

Interpretation:

DAS28 scores are categorized into different disease activity levels:
<2.6: Remission
2.6 – 3.2: Low disease activity
3.2 – 5.1: Moderate disease activity

5.1: High disease activity

Utility:

The DAS28 helps guide treatment decisions and monitor disease progression over time.
Regular assessments using DAS28 can aid in adjusting RA therapies to achieve treatment targets and optimize outcomes for patients.

In summary, the Rheumatoid Arthritis Severity Scale, specifically DAS28, provides a structured approach to evaluating RA severity by integrating joint examination findings, inflammatory markers, and patient-reported outcomes. This comprehensive assessment assists clinicians in managing RA effectively and improving patient care.

Here are 4 Rheumatoid Arthritis related articles you might enjoy:

1. Navigating Rheumatoid Arthritis (RA): 12 Things Not to Do and Potential Consequences if Remission is Not Achieved
2. Is Rheumatoid Arthritis (RA) affecting your other organ’s and system – self check
3. Rheumatoid Arthritis Severity Scale (RASS), a self-assessment guide
4. Unlocking the Emotional Terrain of Early Onset Rheumatoid Arthritis (RA)