Clinical measures of disease activity in patients with early arthritis and established RA. ESR (A) and CRP (B) levels in patients with early resolving arthritis (circles), all patients with early persistent arthritis (squares), early persistent RA (upward triangles) and established RA (downward triangles). Individual values and medians are represented on the graph. Data for ESR and CRP were not normally distributed; the Mann-Whitney test was used for comparison between the outcome groups. A P value <0.05 was considered statistically significant. ESR, erythrocyte sedimentation rate (mm/hour); CRP, C-reactive protein (mg/L). RA, rheumatoid arthritis.