Table 2

Disease characteristics in the cohort and in the nested case–control study in different time periods

Cohort study Nested case–control study
Remainder of the cohort Controls Cases
Disease activity and inflammation
Averages during the first year of follow-up after enrolment
 DAS28 (95% CI) 4.25 (4.23 to 4.27) 4.37 (4.24 to 4.51)4.62 (4.45 to 4.80)
 CRP (mg/L) (95% CI) 13.42 (13.10 to 13.73) 14.27 (12.23 to 16.31)18.50 (14.32 to 22.68)
 ESR (mm/hour) (95% CI) 25.69 (25.36 to 26.02) 27.03 (24.94 to 29.12)30.79 (27.61 to 33.96)
Values within a 6 months risk window before the event/index date
 DAS28 (95% CI) 3.50 (3.31 to 3.69) 4.06 (3.79 to 4.34)
 CRP (mg/L) (95% CI)8.02 (6.12 to 9.93)16.19 (8.12 to 24.26)
 ESR (mm/hour) (95% CI)21.45 (18.93 to 23.97)27.98 (23.68 to 32.29)
Treatment
Time from baseline until event/index date
 Cumulative doses of GC
  Exposure to 0–5 mg/day77.7% (74.2 to 81.3)73.0% (68.2 to 77.7)
  Exposure to ≥10 mg/day4.1% (2.5 to 5.8)5.2% (2.8 to 7.5)
 Cumulative use of Cox-2-Inh.0.12% (0.09 to 0.15)0.15% (0.11 to 0.19)
  • Bold indicates significant values compared to case patients.

  • Cox-2-Inh., inhibitors of cyclooxygenase-2; CRP, C-reactive protein; DAS28, disease activity based on 28 joint count; ESR, erythrocyte sedimentation rate; GC, glucocorticoids; NSAIDs, non-steroidal anti-inflammatory drugs.