Background/Purpose: Visual analogue scales (VAS) are routinely used in daily clinical practice and are part of the different composite outcome measures. Studies often report weak to moderate positive correlations between physician and patient assessment of disease activity. It is thought that they are driven by different considerations such as pain, fatigue and mental status for patients and objective measures such as joint counts and CRP/ESR for physicians. While absolute values of patient and physician global disease activity do not always correlate, changes may offer a better correlation. We evaluated those changes in RA patients initiating a first anti-TNF.

Methods: We extracted from the RHUMADATA® clinical database and registry patient and physician global assessments of disease activity of RA patients treated for at least 6 months with a first anti-TNF agent (adalimumab, etanercept or infliximab). Pearson correlations coefficients between pre, post and pre-post changes in patient and physician assessments were computed (SAS v 9.13) and compared.  We used t-tests to verify if pre-post differences in global assessments were related to disease duration (less or equal to two years vs greater than two years), age (less or equal to 50 years vs greater than 50 years), gender and DAS 28 (less or equal to 3.2 vs greater than 3.2).  A general linear model (GLM) was used to further assess if disease duration, age, gender and DAS score explained the discrepancies in physician and patients pre-post global assessments differences.

Results: The global disease activity scores from 83 patient-physician pairs were available for this analysis. Pre-treatment assessments were made within 0 and 176 days (mean 33 days) of biologic initiation while post treatment assessments occurred between 182 and 799 days (mean 268 days). Patient and physician pre, post, and pre-minus-post global assessment means and standard deviations are presented. The pre and post and change treatment Pearson correlations coefficients between patient and physician assessments are respectively r2=0.34 (p=0.001), r2=0.19 (p=0.08) and 0.15 (p=0.19).

Physician and patient global disease activity assessment
	Physician		Patient		Difference (patient-physician)
	Mean	Std Dev	Mean	Std Dev	Mean	Std Dev
Pre-treatment	5.27	1.98	5.58	2.96	0.31	2.94
Post-treatment	1.42	1.79	3.79	2.81	2.37	3.02
Difference (post-pre)	-3.85	2.31	-1.79	2.95	–

Physician pre-post differences in global assessment were not significantly different across disease duration, gender, age and DAS scores.  Similar results were observed in the patient assessments except for disease duration. Smaller differences were observed in subjects having a disease duration of two years or less. The GLM revealed that no factors other than rater (physician or patient) explained the observed differences

Conclusion: While the pretreatment initiation global disease activity assessments showed moderate correlation, the change in these assessments exhibited a weak relationship. Both physicians and patients agree on disease activity improvement although their magnitudes differ.  Of the factors explored, only rater (physician or patient) seem to explain these differences.

---

« Back to 2014 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/disease-activity-scoring-comparing-patient-and-physician-global-assessment-of-disease-activity-in-rheumatoid-arthritis/