Gender-Stratified Disease Activity Score Improves Inter-Score Agreement in RA

Discordance between 28-joint count Disease Activity Score based on C-reactive protein (DAS28-CRP) and DAS28 based on erythrocyte sedimentation rate (DAS28-ESR) in rheumatoid arthritis (RA) can be significantly improved by adjusting scores by gender, according to a study published in Rheumatology.

In the current study, researchers evaluated the determinants of discordance between scores of the DAS28-ESR and DAS28-CRP and the resulting effect on RA disease activity stratification and treat-to-target approaches. Investigators analyzed 31,074 DAS28-ESR and DAS28-CRP scores from the British Society for Rheumatology Biologics Register for RA.

For the entire cohort, DAS28-CRP scores were an average of 0.3 points lower than corresponding DAS28-ESR scores. The greatest differences between DAS28-ESR and DAS28-CRP scores were seen in women (-0.35) and patients >50 years (-0.34), whereas mean DAS28-CRP scores for men were only 0.15 lower than equivalent DAS28-ESR scores. The discordance between DAS28-ESR and DAS28-CRP scores had a significant effect on disease activity stratification at remission thresholds and low disease activity (66.6% and 32.0% concordance, respectively). Adjusting DAS28-CRP scores according to gender significantly improved the agreement with DAS28-ESR scores (P <.001).

Study investigators concluded, “Our findings suggest the DAS28-ESR and DAS28-CRP should not be used interchangeably when stratifying disease activity. Gender influences inter-score agreement, and adjustment of the DAS28-CRP according to gender significantly improves inter-score reliability.”

One author reported receipt of honoraria and providing consultancy. See original article for further details. 

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Reference

Hamann PDH, Shaddick G, Hyrich K, Green A, McHugh N, Pauling JD. Gender stratified adjustment of the DAS28-CRP improves inter-score agreement with the DAS28-ESR in rheumatoid arthritis [published online December 19, 2018]. Rheumatology (Oxford). doi: 10.1093/rheumatology/key374