Evidence of Diagnostic and Treatment Delay in Seronegative Rheumatoid Arthritis: Missing the Window of Opportunity

To compare the time from first joint swelling to fulfillment of the American College of Rheumatology/European League Against Rheumatism classification criteria between patients with seropositive and seronegative rheumatoid arthritis (RA) and to assess the impact of seronegative status on the time from first joint swelling to initiation of disease-modifying antirheumatic drug (DMARD) therapy and achievement of remission. Times from first provider-documented joint swelling to fulfillment of the 1987 and 2010 American College of Rheumatology/European League Against Rheumatism criteria and to the clinical diagnosis of RA were measured in a population-based cohort of adults with incident RA between January 1, 2009, and December 31, 2014. Disease characteristics and achievement of remission were compared between seropositive (rheumatoid factor positive and/or anti–citrullinated peptide antibody positive) and seronegative (rheumatoid factor negative/anti–citrullinated peptide antibody negative) patients. The median time from first joint swelling to fulfillment of the 1987 (48 [interquartile range (IQR), 0-300] days vs 2 [IQR, 0-45] days; P=.001) and 2010 (14 [IQR, 0-196] days vs 0 [IQR, 0-29] days; P=.004) classification criteria and the median time from first joint swelling to the clinical diagnosis of RA (187 [IQR, 13-503] days vs 11 [IQR, 0-76] days; P