Table 3

IR and HR of composite serious infections in tocilizumab initiators vs abatacept, propensity score-matched with a 1:1 fixed ratio

TocilizumabAbataceptHR (95% CI)Rate difference†
Subjects (n)EventsPerson-yearsIR* (95% CI)Subjects (n)EventsPerson-yearsIR (95% CI)
As-treated analysis
 Medicare385023032317.12 (6.20 to 8.04)385017636594.81 (4.10 to 5.52)1.25 (1.06 to 1.47)2.31 (1.15, 3.47)
 IMS30089026883.35 (2.66 to 4.04)30085426752.02 (1.48 to 2.56)1.58 (1.19 to 2.09)1.33 (0.45, 2.21)
 MarketScan35566826802.54 (1.93 to 3.14)35566527602.36 (1.78 to 2.93)1.14 (0.85 to 1.54)0.18 (−0.65, 1.01)
 Combined10 41438885994.51 (4.06 to 4.96)10 41429590943.24 (2.87 to 3.61)1.40 (1.20 to 1.63)1.27 (0.69, 1.85)
Intention-to-treat analysis up to 180 days
 Medicare385015717419.02 (7.61 to 0.43)385011117526.34 (5.16 to 7.51)1.26 (1.03 to 1.55)2.68 (0.84, 4.52)
 IMS30085113763.71 (2.69 to 4.72)30083213892.30 (1.51 to 3.10)1.34 (0.94 to 1.92)1.41 (0.12, 2.70)
 MarketScan35564415442.85 (2.01 to 3.69)35564515522.90 (2.05 to 3.75)0.96 (0.67 to 1.37)−0.05 (−1.24, 1.14)
 Combined10 41425246615.41 (4.74 to 6.07)10 41418846934.01 (3.43 to 4.58)1.34 (1.11 to 1.63)1.40 (0.52, 2.28)
  • *Incidence rate (IR) is per 100 person-years.

  • †Rate difference per 100 patients (tocilizumab-abatacept).