In PsA, Are You Minimizing What You Can't See?

February 24, 2015
Rita Baron-Faust

The first study to ask about variance between physicians and patients in judging the severity of psoriatic arthritis shows that, as with rheumatoid arthritis, they don't reach similar conclusions.

Eder L, Thavaneswaran A, Chandran V, et al. Factors Explaining the Discrepancy Between Physician and Patient Global Assessment of Joint and Skin Disease Activity in Psoriatic Arthritis Patients. Arthritis Care & Research. 2015;67:264–272, February 2015. doi: 10.1002/acr.22401

While discordance between patient and physician assessment of [[{"type":"media","view_mode":"media_crop","fid":"32331","attributes":{"alt":"psoriatic arthritis","class":"media-image media-image-right","id":"media_crop_3718554051901","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"3422","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"width: 112px; height: 123px; margin: 3px; float: right;","title":" ","typeof":"foaf:Image"}}]]disease activity has been well-reported in rheumatoid arthritis (RA), this is the first major study in to address the issue for psoriatic arthritis (PsA).

As with RA, these authors say, data from 565 patients in the large PsA clinic at Toronto Western Hospital show that patients tend to judge their disease as more severe than their doctors think-especially when it comes to fatigue, pain, disability, and tender and swollen joints.

The predominant differentiating factor was pain, especially for joints where pain explains almost 75% of the variability between these patients’ global assessment (ptGA) scores and their physicians’ global assessment (phGA) scores.

Fatigue factors into around 21% of the discrepancy between patient and physician global assessment scores.

Pain accounts for only about 7% of the phGA scores, while tender and swollen joint counts play a bigger role.

Doctors and patients tended to closer agreement about skin symptoms.

The study group, who’d had PsA for an average of 14 years, were in their early 50s and white, with 60% being men.

Who is most likely to feel (or report) the pain? Those who consistently placed higher levels of intensity on their joint and skin disease tend to:

•   have less education,
•   smoke tobacco, to
•   be unemployed, or to
•   experience more depression, anxiety, and fibromyalgia symptoms.  

Other factors associated with placing high scores on joint disease activity included older age and female gender.

Those living without a partner were more likely to give high scores to skin disease activity.

On the other hand, are there characteristics of physicians that make them more likely to minimize phGA scores? The study did not assess this question.

A better way to manage PsA, these authors suggest, would be to:

•   assess joint  and skin disease separately rather than using a single instrument,
•   investigate the underlying causes of pain and fatigue,
•   adjust treatment accordingly.