Comparison 1. 5‐ASA versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Failure to Induce Global/Clinical Remission	11	2387	Risk Ratio (M‐H, Fixed, 95% CI)	0.86 [0.82, 0.89]
1.1 Dose of 5‐ASA: < 2 g	3	231	Risk Ratio (M‐H, Fixed, 95% CI)	0.92 [0.84, 1.02]
1.2 Dose of 5‐ASA : 2 ‐ 2.9 g	8	956	Risk Ratio (M‐H, Fixed, 95% CI)	0.88 [0.82, 0.94]
1.3 Dose of 5‐ASA: >or=3 g	8	1200	Risk Ratio (M‐H, Fixed, 95% CI)	0.83 [0.77, 0.88]
2 Failure to Induce Global/Clinical Remission or Improvement	14	2256	Risk Ratio (M‐H, Random, 95% CI)	0.68 [0.61, 0.75]
2.1 Dose of 5‐ASA: < 2 g	3	231	Risk Ratio (M‐H, Random, 95% CI)	0.79 [0.64, 0.97]
2.2 Dose of 5‐ASA: 2 ‐ 2.9 g	10	877	Risk Ratio (M‐H, Random, 95% CI)	0.77 [0.67, 0.88]
2.3 Dose of 5‐ASA: >or=3 g	9	1148	Risk Ratio (M‐H, Random, 95% CI)	0.57 [0.51, 0.65]
3 Failure to Induce Endoscopic Remission	4	1154	Risk Ratio (M‐H, Random, 95% CI)	0.77 [0.67, 0.89]
3.1 Dose of 5‐ASA: < 2 g	1	122	Risk Ratio (M‐H, Random, 95% CI)	0.85 [0.64, 1.14]
3.2 Dose of 5‐ASA : 2 ‐ 2.9 g	3	393	Risk Ratio (M‐H, Random, 95% CI)	0.86 [0.70, 1.05]
3.3 Dose of 5‐ASA: >or=3 g	4	639	Risk Ratio (M‐H, Random, 95% CI)	0.70 [0.56, 0.87]
4 Failure to Induce Endoscopic Remission or Improvement	4	416	Risk Ratio (M‐H, Fixed, 95% CI)	0.71 [0.59, 0.86]
4.1 Dose of 5‐ASA: < 2 g	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.2 Dose of 5‐ASA : 2 ‐ 2.9 g	3	265	Risk Ratio (M‐H, Fixed, 95% CI)	0.73 [0.58, 0.92]
4.3 Dose of 5‐ASA: >or=3 g	2	151	Risk Ratio (M‐H, Fixed, 95% CI)	0.69 [0.49, 0.96]
5 Development of Any Adverse Event	8	1218	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.85, 1.07]
5.1 Dose of 5‐ASA: < 2 g	1	30	Risk Ratio (M‐H, Fixed, 95% CI)	1.26 [0.74, 2.13]
5.2 Dose of 5‐ASA : 2 ‐ 2.9 g	5	377	Risk Ratio (M‐H, Fixed, 95% CI)	1.04 [0.82, 1.33]
5.3 Dose of 5‐ASA: >or=3 g	5	811	Risk Ratio (M‐H, Fixed, 95% CI)	0.91 [0.80, 1.05]
6 Withdrawal from Study due to Adverse Event	13	2372	Risk Ratio (M‐H, Fixed, 95% CI)	0.72 [0.54, 0.97]
6.1 Dose of 5‐ASA: < 2 g	3	231	Risk Ratio (M‐H, Fixed, 95% CI)	0.55 [0.19, 1.63]
6.2 Dose of 5‐ASA : 2 ‐ 2.9 g	9	926	Risk Ratio (M‐H, Fixed, 95% CI)	1.13 [0.65, 1.94]
6.3 Dose of 5‐ASA: >or=3 g	9	1215	Risk Ratio (M‐H, Fixed, 95% CI)	0.59 [0.41, 0.87]
7 Withdrawal from Study due to Adverse Event (sensitivity analysis)	12	2091	Risk Ratio (M‐H, Fixed, 95% CI)	0.88 [0.62, 1.24]
7.1 Dose of 5‐ASA: < 2 g	3	231	Risk Ratio (M‐H, Fixed, 95% CI)	0.55 [0.19, 1.63]
7.2 Dose of 5‐ASA : 2 ‐ 2.9 g	9	926	Risk Ratio (M‐H, Fixed, 95% CI)	1.13 [0.65, 1.94]
7.3 Dose of 5‐ASA: >or=3 g	8	934	Risk Ratio (M‐H, Fixed, 95% CI)	0.78 [0.47, 1.26]
8 Exclusions and Withdrawals after Entry	15	2529	Risk Ratio (M‐H, Random, 95% CI)	0.61 [0.51, 0.72]
8.1 Dose of 5‐ASA: < 2 g	3	231	Risk Ratio (M‐H, Random, 95% CI)	0.64 [0.42, 0.98]
8.2 Dose of 5‐ASA : 2 ‐ 2.9 g	11	1014	Risk Ratio (M‐H, Random, 95% CI)	0.70 [0.53, 0.92]
8.3 Dose of 5‐ASA: >or=3 g	10	1284	Risk Ratio (M‐H, Random, 95% CI)	0.52 [0.41, 0.66]