Getting Diagnosed with AxSpA: Why Does it Take So Long?
It often takes many years to be accurately diagnosed with axial spondyloarthritis (AxSpA). It sometimes takes as long as 14 years from the time that symptoms begin.1
There are many reasons why diagnosis is hard for doctors. However, an early referral to a rheumatologist (a doctor with expertise in joint inflammation) can speed diagnosis. Delays in diagnosis can lead to worse outcomes and increase the cost of care. Because of this, some doctors are pushing for more robust standards to identify people who need to be referred to a rheumatologist.
Challenges of diagnosing AxSpA
The biggest challenge in diagnosing AxSpa is that the main symptom is inflammatory back pain (IBP). IBP is common in many other conditions. Also, it takes years for structural damage to the lower back joints to become visible by x-ray.2 Therefore, for non-radiographic AxSpA (nr-AxSpA), there are no symptoms or tests to distinguish it from other conditions.3
As a result, doctors rely on a combination of symptoms, blood tests, and MRI scans to diagnose nr-AxSpA. Symptoms of spondyloarthritis include heel pain, inflammatory bowel disease, family history, response to anti-inflammatory drugs, and psoriasis.4 Blood tests are used to look for inflammatory markers such as the human leukocyte antigen B27 (HLA-B27).
But, HLA-B27 levels vary widely in the general population, causing many people to go undiagnosed.1 And, none of these criteria on their own are specific for nr-AxSpA over other conditions. Doctors must therefore look at each symptom and test result in the context of other factors. This makes diagnosis complicated and subjective.
Other factors affecting AxSpA diagnosis
Doctors have tried but found little success in simplifying diagnosis of AxSpa. The Assessment in Spondylo-Arthritis International Society (ASAS) developed one system in 2009.5 However, they developed the workflow to classify AxSpa, not diagnose it. Furthermore, some necessary tests are not usually ordered by doctors and may be expensive.
Also, certain groups of people tend to experience longer delays in diagnosis than others. One study in 2015 found a longer delay in people with AxSpA if they had a lower educational level.6 Another study in 2019 found 4 factors associated with longer delays:7
- Female sex
- Younger age when symptoms began
- Absence of the HLA-B27 genetic marker
- Presence of psoriasis.
In addition, people with back pain tend to seek care from primary care physicians, orthopedists, and chiropractors who may be unfamiliar with nr-AxSpA symptoms. This causes referral to a rheumatologist to take a long time. After referral, people can be further delayed by a hesitation to see a specialist and insurance restrictions.
Effects of delayed AxSpA diagnosis
Studies have shown that delayed diagnosis is harmful to overall quality of life for people with AxSpA.8 Those with a delayed diagnosis tend to have higher disease activity and worse physical function.6,9 This includes more structural damage to the lower back joints and decreased spinal mobility.
A delayed diagnosis is also connected to higher economic burdens. This is due to a greater chance of work disability and higher healthcare costs.10,11 Finally, a delayed diagnosis is linked to depression, poorer mental health, and worse quality of life.12 This means that decreasing the diagnosis time would reduce the pain caused by AxSpA and improve the financial and mental health of this group of people.
Looking ahead: How can we diagnose AxSpA earlier?
Despite the obstacles, there is reason to be optimistic that diagnosis times for AxSpA will decrease. This is because we know that outcomes are better with a quick referral to a rheumatologist. So, experts know that one solution is to educate non-rheumatologists on ways to identify AxSpA.
A study in 2016 tried to identify effective criteria for referral. The doctors found that for people with chronic pain that lasted at least 3 months and began under age 45 years, looking for at least 1 of the 3 main AxSpA features helped.13 They also found that MRI tests tended to be most important in correctly diagnosing AxSpa.13
Hopefully, increased awareness will soon improve diagnosis time and outcomes for people with AxSpA.
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