Measuring the Value of How a Patient “Feels”

How a patient feels may be a better indicator of the effectiveness of treatment than actual disease activity, researchers say.

For rheumatoid arthritis and psoriatic arthritis patients, the severity of pain, functional capacity, fatigue, sleep disturbance and coping, are factors they consider most important, a previous study shows. Now, a study published in Arthritis Care and Research explores the relationships between the state of symptoms patients deem acceptable by patients (Patient Acceptable Symptom State, or PASS) and patient-perceived impact.

“Low pain and high coping levels appeared to be the main drivers of PASS in both diseases. Since disease activity does not appear to be the main driver, patient-perceived impact is probably more closely related to PASS,” wrote researchers who were led by Laure Gossec, M.D., Ph.D., Sorbonne University, Paris, France.

Acceptable quality of life as judged by patients themselves is a treatment objective in both rheumatoid arthritis and psoriatic arthritis. The Patient Acceptable Symptom State (PASS), developed as a measure of disease status acceptability relative to the concept of “feeling well,” poses the question: “If you were to remain for the next few months as you were during the last week, would this be acceptable or unacceptable to you?”

In past rheumatoid arthritis research, PASS has appeared to be only weakly related to disease activity. The relationship between disease activity and PASS has not been well explored in psoriatic arthritis. Since disease activity does not appear to the main driver of PASS, patient-perceived impact likely has a stronger link with PASS, Gossec et al. suggest.

Patients with rheumatoid arthritis and psoriatic arthritis are impacted primarily by five domains:  pain, functional capacity, fatigue, sleep disorders and coping. The domains are further classified as physical (pain, functional capacity, sleep disturbance), mental (coping) and both mental and physical (fatigue). While past research in several diseases a pain level of about 4 out of 10 has been identified as corresponding to PASS, the levels across other domains are unknown. The Gossec et al. study addressed which symptoms best explain the PASS.

This was a cross-sectional study of data from 977 patients:  531 with rheumatoid arthritis; 446 with psoriatic arthritis; 637 (65.8%) were females; mean age of 53.4 years; and, 11.2 years mean disease duration. The study found that 60.9 percent (n=595) were in PASS, with lower symptom levels in 4 of the 5 assessed health domains (pain, functional capacity, fatigue, coping, but not sleep disturbance).

In multivariate analysis with adjustment for DAS28 (Disease Activity Score 28 joints), however, less pain and better coping were predictive of being in PASS (odds ratio [95% confidence interval] 0.80 [0.67-0.96] and 0.63 [0.52-0.75] for pain and 0.84 [0.74-0.96] and 0.83 [0.71-0.97] for coping, in rheumatoid arthritis and psoriatic arthritis, respectively. In both rheumatoid arthritis and psoriatic arthritis the cut-offs on the 0-10 symptom scale corresponding to PASS for the five domains were between four and five. Patients in PASS versus those not, were well discriminated in all domains, with sleep disturbance having the lowest discriminance (effect size 0.73 and 0.82 in rheumatoid arthritis and psoriatic arthritis respectively). For all domains the effect size ranged from 0.73 to 1.45 in rheumatoid arthritis and from 0.82 to 1.52 in psoriatic arthritis.

Gossec et al. found it surprising that while disease activity as assessed by DAS28-ESR (erythrocyte sedimentation rate) was different in rheumatoid arthritis and psoriatic arthritis, symptom levels and PASS were similar.

The study confirms the theory of an “impact triad” which proposes that the impact of disease is more than symptom severity, it also includes self-management (coping) and symptom importance ^{(Sanderson et al)}. While this suggests targeting symptoms that correspond to a PASS, management of these chronic, erosive diseases also needs to halt or reduce disease progression and structural damage, Gossec et al. state.

“Taking into account how the PASS reflects patient-perceived impact of disease, levels of symptoms corresponding to a PASS might be considered as a clinically relevant treatment target. However, in these chronic, erosive diseases, the ultimate objectives of management are not only quality of life, but also halting or reducing the disease progression. In this regard, patient-reported outcomes overall, and in particular both PASS and levels of symptoms, lack predictive value for later evolution of structural damage or other ‘hard’ outcomes,” the authors wrote.

References:

​Déborah Puyraimond-Zemmour, MD , Adrien Etcheto, MSc , Bruno Fautrel, MD, PhD et al. “Associations between five important domains of health and the Patient Acceptable Symptom State in rheumatoid arthritis and psoriatic arthritis: a cross sectional study of 977 patients.” Arthritis Care & Research. Published online Dec. 20, 2016. DOI: 10.1002/acr.23176 and the Patient A