Establishing Goals of Therapy in Axial Spondyloarthritis

Atul A. Deodhar, MD: The goals of therapy for patients with axial spondyloarthritis include improving their signs and symptoms. We want to give them a better quality of life, reduce their pain and stiffness, and improve their mobility. These are important goals because that’s what bothers the patient in day-to-day life and affects their work. We have excellent medication, which I’ll come to in a minute.

The next goal, which is currently aspirational, is to prevent further radiographic damage. We don’t have any prospective studies to show that any of the therapies actually stop or reduce the rate of progression. We have very strong hints based on looking at the data of large cohorts of patients that we have followed for many years. What we have found is that patients who are treated with biologics, especially with tumor necrosis factor inhibitors for long periods of time, have reduced rates of progression. That’s retrospective. To really say there is a cause-and-effect relationship, we will need prospective studies of long duration. We are looking to see that patients who are receiving these drugs are not only improving their quality of life by reducing signs and symptoms but are also improving their quality of life by reducing radiographic progression. But currently, that is aspirational. We are heading there, but we are not there as of yet.

In day-to-day practice, we do measure the patient’s disease activity. There are several methods for doing this. The simpler one that I use in my practice is called the BASDAI—Bath Ankylosing Spondylitis Disease Activity Index—which is just 6 questions. It’s a patient-reported outcome. There is a question about fatigue, a question about neck and back pain, a question about peripheral arthritis, etc, and also about morning stiffness. This has been validated. This is what we use in daily practice. This is even what is used in clinical trials.

There is a more complicated one, which is called the ASDAS, Ankylosing Spondylitis Disease Activity Score. ASDAS is not used in day-to-day practice in the United States. It’s a much more complicated formula. It’s a newer one. It takes some of the questions from the BASDAI and also asks the patient about their overall assessment of their disease. It considers all the ways in which health and disease affect the patient. The additional thing that ASDAS considers, which BASDAI does not, is the level of C-reactive protein [CRP]. C-reactive protein is measured through a blood test, and it tells you about inflammation. So the BASDAI, which we use daily, is criticized because it is purely patient driven. It is subjective. The ASDAS has some objective measure with the CRP. But the problem with the ASDAS is that it has a complicated formula. You need to use a calculator. It is not as simple as the BASDAI, which is very easy to calculate. We can figure things out within a few seconds, in fact.