The modified Disease Activity Score in 28 joints with C-reactive protein (DAS28-CRP) is a strong predictor of rapid radiographic progression in patients with early rheumatoid arthritis (RA), according to research results published in ACR Open Rheumatology.
Using data from PREMIER, a 2-year, multicenter, double-blind, active comparator-controlled, phase 3 clinical trial, researchers aimed to determine which measures of disease activity best predicted rapid radiographic progression in a population of patients with early RA. They examined the DAS28-CRP; modified DAS28-CRP, using weighted coefficients of CRP, physician global assessment, and swollen joint count in 28 joints; Clinical Disease Activity Index; and patient-reported outcomes, including the patient global assessment and the Health Assessment Questionnaire Disability Index.
Disease activity measures were taken at baseline and at 3-month follow-up. Investigators defined rapid radiographic progression as a change in the modified total Sharp score of >3.5 between baseline and 12 months. A decrease in DAS28-CRP >1.2 from baseline to 3 months was considered an improvement in disease.
In total, 149 patients were included in the analysis (mean age, 52.9±13.3 years; 75.8% women; mean RA duration, 0.8±0.9 years; 85.2% rheumatoid factor positive). Mean DAS28-CRP was 6.3±0.9, mean Clinical Disease Activity Index was 44.7±12.2, and mean modified DAS28-CRP was 5.1±1.3. With regard to therapies, 30.9% of patients were previously treated with conventional synthetic disease-modifying antirheumatic drugs, whereas 41.6% of patients were treated with steroids.
At baseline, modified DAS28-CRP was the strongest predictor of rapid radiographic progression at 12 months (adjusted odds ratio [aOR], 3.29; 95% CI, 1.70-6.36); other measures of RA showed no significant effect on progression at 12 months. The area under the curve (AUC) for modified DAS28-CRP at baseline was also higher compared with other measures (AUC, 0.66; 95% CI, 0.57-0.74), with a significant difference noted for AUC between the modified DAS28-CRP and DAS28-CRP (AUC difference, 0.10; P =.02).
At 3 months, investigators found that all disease activity measures and patient-reported outcomes were significant predictors for rapid radiographic progression. Despite this, only modified DAS28-CRP was a significant predictor at 12 months after applying the multivariate analysis and adjusting for potential confounders (aOR, 2.56; 95% CI, 1.43-4.56). Investigators also noted that the effect of modified DAS28-CRP at 3 months was less than its effect at baseline.
Results of a multivariable logistic regression analysis demonstrated that CRP at baseline and 3 months (aORs, 2.82 and 4.03, respectively) had the strongest effect on radiographic progression predictions at 12 months.
Per the Youden index, investigators found that the optimal cutoff point for the modified DAS28-CRP at baseline was 4.5 (positive and negative predictive values 50% and 76%, respectively) in predicting rapid radiographic progression at 1 year. The 3-month corresponding optimal cutoff point for the modified DAS28-CRP was 2.6 (positive and negative predictive values 59% and 81%, respectively).
The study was limited by its relatively small sample size in the original study and an inability to access data from all treatment groups in the PREMIER study.
“[A] modified version of disease activity scores, such as the [modified DAS28], might be beneficial as an alternative measure of disease activity for rheumatologists in the routine care setting for their treat-to-target approach,” the researchers concluded.
Disclosure: This clinical trial was supported by Horizon Therapeutics. Please see the original reference for a full list of authors’ disclosures.
Movahedi M, Weber D, Akhavan P, Keystone EC. Modified disease activity score at 3 months is a significant predictor for rapid radiographic profession at 12 months compared with other measures in patients with rheumatoid arthritis. ACR Open Rheumatol. 2020;2(3):188-194.