This scale was developed to help doctors measure disease activity in people with rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic, progressive condition that affects your joints. Understanding its severity is an important factor in helping you and your doctor evaluate whether treatments are working, what treatments to consider next, and how to prevent further progression and damage.

The Rheumatoid Arthritis Severity Scale (RASS) was developed in the early 2000s to help doctors determine disease activity, as well as functional impairment and physical damage caused by RA. However, newer assessments are now more widely used to measure disease activity.

RA causes inflammation of the cells in the lining of your joints, which results in swelling, stiffness, and pain. This inflammation involves the affected joints and the surrounding tissues, including tendon sheaths.

RA can sometimes be difficult to diagnose. This is because joint pain and fatigue are not specific to RA — they can occur as part of other health conditions as well.

To diagnose RA, doctors rely on:

  • your medical history
  • a physical examination
  • blood tests
  • X-rays of your hands and feet

Your doctor may refer you to a specialist called a rheumatologist to confirm an RA diagnosis. If you’re experiencing persistent joint pain and swelling and you don’t yet have a diagnosis, you should get a referral to a rheumatologist.

A rheumatologist can provide an accurate assessment of your disease activity and determine which of the following types of RA you might have:

  • Seropositive RA: In this type, you test positive for cyclic citrullinated peptide (CCP) antibodies and rheumatoid factor (RF).
  • Seronegative RA: In this type, you test negative for CCP and RF.
  • Juvenile RA: This type, also called juvenile idiopathic arthritis, affects children ages 16 years and younger.

After diagnosing RA, your doctor should monitor and track the level and progression of the disease.

Before RASS, doctors estimated RA severity by using a combination of results from a physical examination; factors reported by a person with RA, such as pain level; and inflammatory blood markers.

Another measurement, the Health Assessment Questionnaire, asks people with RA to rate their pain level. But because people have different thresholds for pain, self-reported assessments can be inaccurate.

Experts continue to develop new methods of tracking RA activity and progression over time. With the current understanding of RA and inflammation, there are various effective methods for assessing RA activity and severity.

RASS measures three aspects of RA:

  • disease activity
  • functional impairment
  • physical damage

Each one is assessed using a range of 1 to 100. A score of 1 means there’s no evidence of the condition, whereas 100 refers to the maximum level of progression.

Doctors look for disease activity, such as joint swelling, during a physical exam. They use range-of-motion exercises to check for functional impairment. The physical damage component of the RASS is a rating of how much permanent damage RA has caused.

Disease Activity Score (DAS)

The DAS determines whether RA is in remission or whether there is low, moderate, or severe disease activity. This may be the most important of the three scores for you to be familiar with.

Knowing your DAS will help you and your doctor assess whether treatments are working or if they need to be changed.

Signals of Functional Impairment (SOFI)

Your doctor determines SOFI by looking at how far and how well you can move your hands, arms (upper SOFI), and legs (lower SOFI). Your doctor also looks at how quickly you can walk a certain distance, either with or without an assistive device such as a cane or walker.

Physical damage

The final aspect of the RASS looks at how much physical damage the condition has caused in your cartilage and joints. This step involves imaging scans such as X-rays, MRI scans, or CT scans.

For the physical damage component, your doctor will look for scarring and destruction or deformity of the joints affected by RA and the bones around them.

Several scales are now available to measure RA severity. As a result, the RASS isn’t as widely used as it once was.

As of 2019, the American College of Rheumatology recommends that doctors use any of these RA severity scales:

  • Clinical Disease Activity Index
  • Disease Activity Score 28 Joints
  • Routine Assessment of Patient Index Data 3
  • Simplified Disease Activity Index
  • Patient Activity Scale-II

Some doctors may also use other scales and assessment tools to analyze your RA, such as:

  • Disease Activity Score
  • Hospital Universitario La Princesa Index
  • Multi-Biomarker Disease Activity Score
  • Patient-Derived DAS28
  • Rheumatoid Arthritis Disease Activity Index
  • Rheumatoid Arthritis Disease Activity Index 5
  • Routine Assessment of Patient Index Data 5

Why is my rheumatoid factor over 100?

Your doctor may order a test to measure the rheumatoid factor in your blood.

Typical findings are less than 20 units per milliliter. A rheumatoid factor level over 100 is strongly associated with autoimmune conditions such as RA. However, a high rheumatoid factor level can also indicate cancer, chronic infections, bacterial endocarditis, or other autoimmune disorders.

What are the 4 stages of rheumatoid arthritis?

RA consists of four stages, each of which has specific symptoms and treatment goals:

  • Stage 1: Stage 1 is considered early stage RA and involves inflammation inside the joint, which leads to swelling of the tissues but no damage visible on an X-ray. You may notice joint stiffness, swelling, or pain.
  • Stage 2: This is moderate stage RA. It’s characterized by inflammation in the lining of your joints that causes damage to your joint cartilage, but no joint deformity is visible on an X-ray. At this stage, RA may result in pain, loss of mobility, and decreased range of motion in the affected joint.
  • Stage 3: This stage is considered severe RA because the damage extends to your bones, and deformity may be visible on an X-ray. You might experience increased joint pain and swelling because the cushion between the bones in a joint is gone.
  • Stage 4: This is end stage RA, in which an X-ray detects fused joints. As a result, the joints no longer work properly.

Is rheumatoid arthritis considered severe?

Yes, RA can be severe because it’s a chronic autoimmune condition that progresses as you age. Stage 3 RA is considered severe because the damage extends from your cartilage to your bones, causing increased pain, swelling, mobility loss, and deformity.

If left untreated, RA can reach stage 4, which is considered end stage RA. At this stage, your joints become fused and stop working.

How is severe rheumatoid arthritis pain treated?

Your doctor may recommend a combination of medication and self-management strategies to treat severe RA pain. While there is no cure for RA, the right treatment and management plan can help relieve symptoms and slow down disease progression.

Medications that can slow the progression of RA include:

  • disease-modifying antirheumatic drugs
  • biologic drugs
  • Janus kinase inhibitors

These drugs help reduce symptoms while preventing joint damage and disability.

In addition, your treatment plan might include pain relief options such as nonsteroidal anti-inflammatory drugs (NSAIDs), COX-2 inhibitors, and corticosteroids.

You might also be able to use self-management strategies to help relieve pain and improve your quality of life. These may include:

  • physical therapy
  • occupational therapy
  • dietary changes
  • RA-specific supplements
  • rest
  • massage
  • yoga
  • acupuncture
  • tai chi
  • meditation
  • chiropractic care

Diagnosing RA may not be easy because symptoms such as joint pain and fatigue can be similar to those of many other conditions.

Once you receive an RA diagnosis, your doctor will need to determine the severity of your condition in order to choose the best treatment for you. Monitoring disease activity is important to help you and your doctor understand how well treatment is working and whether the condition is progressing.

Various scales are available to measure RA severity, including RASS. However, RASS isn’t as widely used as it once was. Your doctor might use newer scales to pinpoint the severity of your disease and the effectiveness of treatment.