Increasing Treatment in Early Rheumatoid Arthritis Is Not Determined by the Disease Activity Score But by Physician Global Assessment: Results from the CATCH Study

Abstract

To determine the factors most strongly associated with an increase in therapy of early rheumatoid arthritis (ERA). Data from the Canadian Early Arthritis Cohort (CATCH) were included if the patient had ≥ 2 visits and baseline and 6 months data. A regression analysis was done to determine factors associated with treatment intensification. Of 1145 patients with ERA, 790 met inclusion criteria; mean age was 53.4 years (SD 14.7), mean disease duration 6.1 months (SD 2.8), 75% were female, baseline Disease Activity Score-28 (DAS28) was 4.7 (SD 1.8) and 2.9 (SD 1.8) at 6 months for included patients. Univariate factors for intensifying treatment were physician global assessment (MDGA; OR 7.8 and OR 7.4 at 3 and 6 months, respectively, p < 0.0005), swollen joint count (SJC; OR 4.7 and OR 7.3 at 3 and 6 months, p < 0.0005), and DAS28 (OR 3.0 and OR 4.6 at 3 and 6 months, p < 0.0005). In the regression model only MDGA was strongly associated with treatment intensification (OR 1.5 and OR 1.2 at 3 and 6 months, p < 0.0005); DAS28 was not consistently predictive (OR 1.0, p = 0.987, and OR 1.2, p = 0.023, at 3 and 6 months). DAS28 was the reason for treatment intensification 2.3% of the time, compared to 51.7% for SJC, 49.9% for tender joint count, and 23.8% for MDGA. For the same SJC, larger joint involvement was more likely to influence treatment than small joints at 3 months (OR 1.4, p = 0.027). MDGA was strongly associated with an increase in treatment at 3 and 6 months in ERA, whereas DAS28 was not. Physicians rarely stated that DAS28 was the reason for increasing treatment.