Patient global assessment in RA: Keep or replace? Experts debate utility in treat-to-target
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While the patient global assessment has utility in measuring personal experience in rheumatoid arthritis, some experts believe that eliminating or replacing it with another measure may be preferable, according to presenters who debated the issue at the EULAR 2021 Congress.
José Antonio P. da Silva, MD, professor of rheumatology at the University of Coimbra, in Portugual, made the case for replacing the PGA, while Maarten Boers, MD, professor of clinical epidemiology in the department of epidemiology and biostatistics at VU University Medical Center, in Amsterdam, argued for keeping the PGA.
“It is essentially a measure of disease impact, not disease activity,” da Silva said. “It is poorly related to disease activity, especially at the low levels of activity. It blurs the target in terms of disease activity.”
At the crux of the matter is the movement in rheumatology toward treating to the target of sustained remission. More specifically, da Silva highlighted patients who have reached the target of remission but are in “near remission” based on the four American College of Rheumatology/EULAR criteria.
Replace PGA with Patient Input
Many patients reach clinical targets as assessed by tender and swollen joint counts and C-reactive protein but fail to meet the definition of remission because of their PGA score.
“We have arrived at the conclusion that PGA is responsible for 60% to 80% of cases of near remission, where remission is not achieved due to a single one of these factors,” da Silva said. “Their disease process is already under control. They can’t get any better.”
There is one key reason why this could be problematic, according to da Silva. “They are at extreme risk for overtreatment,” he said.
Looking deeper into this issue, da Silva believes that remission and so-called “PGA near remission” are essentially the same.
For clinicians who are concerned that removing PGA from the four criteria for defining remission, da Silva suggested that using just the disease activity parameters and assessing disease impact separately has “performed well in predicting radiographic damage” in early trials.
If there is a parameter that may be a candidate for replacing the PGA and assessing patient status separately, it is the Rheumatoid Arthritis Impact of Disease (RAID) score, according to da Silva. However, he acknowledged that further study is necessary to determine how it would be applied and if it would be an improvement over the PGA.
Ultimately, da Silva had one key message about replacing the PGA. “[Patients] should have more voice in measuring disease impact,” he said. “It should be the patient’s own target. Whatever the patient defines as a target should be important to the clinician. This should be central to the clinician’s decision making.”
Keep PGA in Remission
Opening his argument, Boers acknowledged that PGA is flawed. However, he believes it is an important measure because it may be the only sign of “smoldering disease” in a patient who, otherwise, meets lab criteria and those for tender and swollen joints. “Maybe the disease is still a little bit active in a patient, but PGA is the only sign of this," he said. “The PGA may not be very good, but sometimes it is an important measure.”
Another issue for Boers is that remission is actually not very well-defined. He suggested the reason for this is that remission criteria such as DAS28 were not designed for the clinic. “They were intended to define a homogenous population for research,” he said. “It is unfair to blame them for problems in the clinic because that was not their intended use.”
There are clinical issues with remission as a target, as well, according to Boers. “We do not have treatments to move patients into a better state than ‘good’,” he said.
Moreover, even if those treatments existed, there are still not sufficient tools and biomarkers to move patients out of that “good” state, where all parameters, including PGA, are accurately assessed, according to Boers.
Beyond these complications, Boers offered a simple reason why the PGA can be so confounding. “Some patients will never have good physical function because of all that is going on in their lives and the other diseases they are having,” he said.
With that in mind, for Boers, then, replacing the PGA with another, similar tool may be beside the point. “Use the PGA wisely,” he said, and suggested that getting back to the basics of the doctor-patient relationship may allow the tool to be used optimally. “Talk to the patient. Ask what is going on. I don’t see any inflamed joints but your PGA is high. Why is that?”
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Boers M, da Silva JP. Patients' input in the target(s). Presented at EULAR 2021 Congress; June 2-6, 2021 (virtual meeting).
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