Drug treatment in ERA at onset, 6 months, 12 months, 18 months and end of follow-up.

Biologic agents were etanercept and adalimumab. NSAID, non-steroidal anti-inflammatory drug; DMARD, disease-modifying anti-rheumatic drug. †frequency/total, n (%), between-group comparisons: chi-square test. § frequency/total, n (%), between-group comparisons: continuity correction. *p<0.05 denotes a significant difference between different groups. Drug treatment in ERA at onset, 6 months, 12 months, 18 months and end of follow-up.