CRP and rheumatoid arthritis: The present study further confirmed that the SII index was moderately positively correlated with both DAS28 scores (DAS28-CRP: r = 0.557, 95 % CI 0.427‒0.665; DAS28-ESR: r = 0.624, 95 % CI 0.507‒0.719) in patients with MDA/HDA-RA.