Comparison 4. Abatacept versus placebo (by dosage).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 ACR 20% improvement	5		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.1 6 months ‐ 2 mg/kg	1	121	Risk Ratio (M‐H, Fixed, 95% CI)	1.58 [0.92, 2.71]
1.2 6 months ‐ 10 mg/kg	4	1527	Risk Ratio (M‐H, Fixed, 95% CI)	1.81 [1.60, 2.04]
1.3 6 months ‐ combined dosage	5	1648	Risk Ratio (M‐H, Fixed, 95% CI)	1.79 [1.59, 2.02]
2 ACR 50% improvement	5		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
2.1 6 months ‐ 2 mg/kg	1	121	Risk Ratio (M‐H, Fixed, 95% CI)	1.33 [0.63, 2.83]
2.2 6 months ‐ 10 mg/kg	4	1527	Risk Ratio (M‐H, Fixed, 95% CI)	2.59 [2.07, 3.25]
2.3 6 months ‐ combined dosage	5	1648	Risk Ratio (M‐H, Fixed, 95% CI)	2.47 [2.00, 3.07]
3 ACR 70% improvement	5		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
3.1 6 months ‐ 2 mg/kg	1	121	Risk Ratio (M‐H, Fixed, 95% CI)	8.17 [0.49, 136.81]
3.2 6 months ‐ 10 mg/kg	4	1527	Risk Ratio (M‐H, Fixed, 95% CI)	3.43 [2.34, 5.04]
3.3 6 months ‐ combined dosage	5	1648	Risk Ratio (M‐H, Fixed, 95% CI)	3.53 [2.41, 5.16]