Ten RCTs were included, four of infliximab therapy (n=602) and six of etanercept therapy (n=1,694).
All 10 RCTs were of a high quality, scoring 5 out of 5 on the Jadad checklist.
ACR20.
Etanercept versus placebo (4 studies): the RR was4.29 (95% CI: 3.12, 5.88) and the RD was 0.44 (95% CI: 0.39, 0.49). Etancercept showed a statistically significant effect over placebo.
Infliximab versus placebo (4 studies): the RR was 3.55 (95% CI: 2.33, 5.41) and the RD was 0.37 (95% CI: 0.25, 0.48). Infliximab showed a statistically significant effect over placebo.
All arms combined versus placebo: the RR was 4.01 (95% CI: 3.12, 5.17) and the RD was 0.41 (95% CI: 0.35, 0.46). All treatment arms combined showed a statistically significant effect over placebo.
ACR50.
Etanercept versus placebo (4 studies): the RR was 5.90 (95% CI: 3.44, 10.12) and the RD was 0.25 (95% CI: 0.20, 0.29). Etancercept showed a statistically significant effect over placebo.
Infliximab versus placebo (4 studies): the RR was 4.30 (95% CI: 2.37, 7.80) and the RD was 0.26 (95% CI: 0.20, 0.32). Infliximab showed a statistically significant effect over placebo.
All arms combined versus placebo: the RR was 5.17 (95% CI: 3.46, 7.71) and the RD was 0.25 (95% CI: 0.22, 0.29). All treatment arms combined showed a statistically significant effect over placebo.
ACR70.
Etanercept versus placebo (1 study): the RR was 9.60 (95% CI: 2.74, 33.68) and the RD was 0.10 (95% CI: 0.06, 0.13). Etancercept showed a statistically significant effect over placebo.
Infliximab versus placebo (1 study): the RR was 7.76 (95% CI: 1.94, 31.15) and the RD was 0.15 (95% CI: 0.10, 0.20). Infliximab showed a statistically significant effect over placebo.
All arms combined versus placebo: the RR was 8.73 (95% CI: 3.44, 22.15) and the RD was 1.12 (95% CI: 0.07, 0.16). All treatment arms combined showed a statistically significant effect over placebo, although there was some statistical heterogeneity between the studies.
Health Assessment Questionnaire.
Etanercept versus placebo (3 studies): the WMD was -0.48 (95% CI: -0.71, -0.25). Etancercept showed a statistically significant effect over placebo, although the studies were heterogeneous.
Infliximab versus placebo (1 study): the WMD was -0.20 (95% CI: -0.34, -0.06). Infliximab showed a statistically significant effect over placebo.
All arms combined versus placebo: the WMD was -0.40 (95% CI: -0.62, -0.18). All treatment arms combined showed a statistically significant effect over placebo, although the studies were heterogeneous.
Patient global assessment.
Etanercept versus placebo (4 studies): the WMD was -2.25 (95% CI: -2.87, -1.63). Etancercept showed a statistically significant effect over placebo, although the studies were heterogeneous.
Infliximab versus placebo (1 study): the WMD was -1.50 (95% CI: -2.13, -0.87). Infliximab showed a statistically significant effect over placebo.
All arms combined versus placebo: the WMD was -2.12 (95% CI: -2.68, -1.55). All treatment arms combined showed a statistically significant effect over placebo, although the studies were heterogeneous.
Swollen joint counts.
Etanercept versus placebo (5 studies): the WMD was -6.58 (95% CI: -12.02, -1.15). Etancercept showed a statistically significant effect over placebo, although the studies were heterogeneous.
Infliximab versus placebo (3 studies): the WMD was -9.48 (95% CI: -14.01, -4.94). Infliximab showed a statistically significant effect over placebo, although the studies were heterogeneous.
All arms combined versus placebo: the WMD was -7.77 (95% CI: -11.37, -4.17). All treatment arms combined showed a statistically significant effect over placebo, although the studies were heterogeneous.
Etanercept versus methotrexate (1 study).
ACR20: for combined etanercept arms versus methotrexate, the RR was 1.03 (95% CI: 0.9, 1.17). For etanercept 25 mg versus methotrexate, the RR was 1.12 (95% CI: 0.96, 1.29). Neither dose showed a statistically significant treatment effect over methotrexate.
Serious adverse events occurred infrequently and were comparable to placebo.