Determinants of discordance in patients' and physicians' rating of rheumatoid arthritis disease activity

Abstract

Objective: To assess the determinants of patients' (PTGL) and physicians' (MDGL) global assessment of rheumatoid arthritis (RA) activity and factors associated with discordance among them.

Methods: A total of 7,028 patients in the Quantitative Standard Monitoring of Patients with RA study had PTGL and MDGL assessed at the same clinic visit on a 0-10-cm visual analog scale (VAS). Three patient groups were defined: concordant rating group (PTGL and MDGL within ±2 cm), higher patient rating group (PTGL exceeding MDGL by >2 cm), and lower patient rating group (PTGL less than MDGL by >2 cm). Multivariable regression analysis was used to identify determinants of PTGL and MDGL and their discordance.

Results: The mean ± SD VAS scores for PTGL and MDGL were 4.01 ± 2.70 and 2.91 ± 2.37, respectively. Pain was overwhelmingly the single most important determinant of PTGL, followed by fatigue. In contrast, MDGL was most influenced by swollen joint count (SJC), followed by erythrocyte sedimentation rate (ESR) and tender joint count (TJC). A total of 4,454 (63.4%), 2,106 (30%), and 468 (6.6%) patients were in the concordant, higher, and lower patient rating groups, respectively. Odds of higher patient rating increased with higher pain, fatigue, psychological distress, age, and morning stiffness, and decreased with higher SJC, TJC, and ESR. Lower patient rating odds increased with higher SJC, TJC, and ESR, and decreased with lower fatigue levels.

Conclusion: Nearly 36% of patients had discordance in RA activity assessment from their physicians. Sensitivity to the "disease experience" of patients, particularly pain and fatigue, is warranted for effective care of RA.

Figure 1

Partial R² plot showing variance explained by individual variables after controlling for effect of the remaining variable for (A) patient’s global assessment and (B) physician’s global assessment of rheumatoid arthritis (RA) disease activity. SJC28 = swollen joint count on 28-joint assessment; HAQ = Health Assessment Questionnaire; TJC28 = tender joint count on 28-joint assessment; ESR = erythrocyte sedimentation rate; Psych HAQ = psychological HAQ; BMI = body mass index.

Figure 2

Degree of concordance among patient and physician assessment of rheumatoid arthritis disease activity across different countries as shown by Lin’s concordance coefficient (vertical lines show the 95% confidence interval). The values after the countries show the number of patients from each country.