New cut-offs for the DAPSA may aid disease activity scoring

The DAPSA is a disease-specific, validated and feasible tool for the assessment of psoriatic arthritis.

INTRODUCTION
Psoriatic arthritis is a chronic inflammatory disease that affects a person’s joints, causing pain and disability. The disease often causes swelling of the fingers and toes. It gets its name from the link between this type of arthritis and a skin condition called psoriasis, which causes redness and scaling. Being able to measure disease activity in psoriatic arthritis allows doctors to see how well medicines are working. There are many different disease activity scores available that look at different parameters. The Disease Activity Index for Psoriatic Arthritis (also known as DAPSA) is one of these and has been developed to include a series of key disease elements. High disease activity generally means that a person’s disease is not well controlled, and may be causing joint damage and pain. Being in low disease activity or remission (no signs of symptoms) is the goal of treatment for psoriatic arthritis.

WHAT DID THE AUTHORS HOPE TO FIND?
The authors wanted to be able to work out how they could use the DAPSA to say when people had achieved certain states (such as remission), or to say whether their treatment was working.

WHO WAS STUDIED?
The study looked at 30 people with psoriatic arthritis, as well as data from 425 patients in three trials: the ADEPT, IMPACT, and GO-REVEAL studies, which investigated the efficacy of three different tumour necrosis factor inhibitors called adalimumab, infliximab and golimumab in patients with psoriatic arthritis who had not seen an improvement in their disease with traditional treatments known as disease-modifying antirheumatic drugs (DMARDs) or non-steroidal anti-inflammatory drugs (NSAIDs).

HOW WAS THE STUDY CONDUCTED?
The authors used patient profiles from an observational database. They then carried out a survey among doctors who were experts in joint diseases to sort these 30 patients into one of four groups (remission, low, moderate, or high disease activity) based on how many swollen or tender joints they had, their level of pain, and laboratory measurements of markers in their blood that indicate inflammation. Based on the distribution of the DAPSA results they then defined the cut-offs between groups. The authors then repeated the test without certain elements, and checked against published study data to see how well the DAPSA results agreed with other disease activity states used.

WHAT WERE THE MAIN FINDINGS OF THE STUDY?
The authors found that the DAPSA is a good tool to use for assessing disease activity in psoriatic arthritis, and that it agrees well with other scoring systems. The DAPSA scores were very different for the people in each of the four groups. The authors conclude that DAPSA scores of 4 or less mean a person is in remission. Scores of 4–14 suggest low disease activity, 14–28 for medium disease activity, and more than 28 means a person has high disease activity. ARE THESE FINDINGS NEW? Yes, up until now definitions of disease activity states and therapeutic response have been missing for the DAPSA.

WHAT ARE THE LIMITATIONS OF THE STUDY?
One limitation is that the study used a small number of patient profiles. However, the authors compared the information with real-life patients from the ADEPT, IMPACT, and GO-REVEAL studies and found similar patterns, which means that the results are reliable, even for this small set of patients.

WHAT DO THE AUTHORS PLAN ON DOING WITH THIS INFORMATION?
The authors plan to repeat the test in large-scale observational studies of people with psoriatic arthritis.

WHAT DOES THIS MEAN FOR ME?
If you have psoriatic arthritis, tools like the DAPSA may help your doctor to assess whether your treatment is working. The DAPSA may also help them to target remission or low disease activity by using a treat-to-target approach.

Disclaimer: This is a summary of a scientific article written by a medical professional (“the Original Article”). The Summary is written to assist non medically trained readers to understand general points of the Original Article. It is supplied “as is” without any warranty. You should note that the Original Article (and Summary) may not be fully relevant nor accurate as medical science is constantly changing and errors can occur. It is therefore very important that readers not rely on the content in the Summary and consult their medical professionals for all aspects of their health care and only rely on the Summary if directed to do so by their medical professional. Please view our full Website Terms and Conditions.

Date prepared: May 2016

Summary based on research article published on: 12 August 2015

From: Schoels, MM. et al. Disease activity in psoriatic arthritis (PsA): defining remission and treatment success using the DAPSA score. Ann Rheum Dis 2016;75:811–18. doi:10.1136/annrheumdis-2015-207507

Copyright © 2016 BMJ Publishing Group Ltd & European League Against Rheumatism. Medical professionals may print copies for their and their patients and students non commercial use. Other individuals may print a single copy for their personal, non commercial use. For other uses please contact our Rights and Licensing Team.

FURTHER READING
Ramiro S, et al. Pharmacological treatment of psoriatic arthritis: a systematic literature review for the 2015 update of the EULAR recommendations for the management of psoriatic arthritis. Ann Rheum Dis 2016;75:490–98. Available at: http://www.eular.org/recommendations_management.cfm