What do systematic reviews say?

Infliximab vs placebo

It is very uncertain whether infliximab changes serious adverse events (at 54 weeks) compared with placebo (very low certainty).

• Infliximab for maintenance of medically‐induced remission in Crohn's disease 2024 · Cochrane Headline outcomes only
  RR 0.6 [0.36, 1]
  1 study · 282 participants
  Very low

Vedolizumab vs placebo

Vedolizumab showed no clear difference in serious adverse events (6–10 weeks) compared with placebo (low certainty).

• Vedolizumab for induction and maintenance of remission in Crohn's disease 2023 · Cochrane Headline outcomes only
  RR 0.91 [0.62, 1.33]
  4 studies · 1126 participants
  Low

Vedolizumab vs placebo

Vedolizumab showed no clear difference in serious adverse events (52–60 weeks) compared with placebo (low certainty).

• Vedolizumab for induction and maintenance of remission in Crohn's disease 2023 · Cochrane Headline outcomes only
  RR 0.98 [0.68, 1.39]
  3 studies · 894 participants
  Low

Two infusions of natalizumab (300 mg or 3 mg/kg) vs placebo

Two infusions of natalizumab (300 mg or 3 mg/kg) showed no clear difference in serious adverse events up to week 12 compared with placebo (low certainty).

• Natalizumab for induction of remission in Crohn's disease 2018 · Cochrane Headline outcomes only
  RR 0.82 [0.29, 2.3]
  1 study · 129 participants
  Low

Two infusions of natalizumab (6 mg/kg) vs placebo

Two infusions of natalizumab (6 mg/kg) showed no clear difference in serious adverse events up to week 12 compared with placebo (low certainty).

• Natalizumab for induction of remission in Crohn's disease 2018 · Cochrane Headline outcomes only
  RR 1.06 [0.38, 2.95]
  1 study · 114 participants
  Low

Three infusions of natalizumab (300 mg) vs placebo

Three infusions of natalizumab (300 mg) showed no clear difference in serious adverse events up to week 12 compared with placebo (low certainty).

• Natalizumab for induction of remission in Crohn's disease 2018 · Cochrane Headline outcomes only
  RR 0.76 [0.37, 1.56]
  2 studies · 1414 participants
  Low

Three infusions of natalizumab (300 mg) and two infusions of infliximab (5 mg/kg) vs placebo and two infusions of infliximab

Three infusions of natalizumab (300 mg) and two infusions of… showed no clear difference in serious adverse events up to week 10 compared with placebo and two infusions of infliximab (low certainty).

• Natalizumab for induction of remission in Crohn's disease 2018 · Cochrane Headline outcomes only
  RR 0.52 [0.03, 7.98]
  1 study · 79 participants
  Low

One infusion of natalizumab (300 mg or 3 mg/kg) vs placebo

One infusion of natalizumab (300 mg or 3 mg/kg) showed no clear difference in serious adverse events up to week 12 compared with placebo (low certainty).

• Natalizumab for induction of remission in Crohn's disease 2018 · Cochrane Headline outcomes only
  RR 0.93 [0.34, 2.49]
  1 study · 131 participants
  Low

Probiotics vs placebo

• Probiotics for maintenance of remission in ulcerative colitis 2020 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 351 participants
  GRADE not reported

IM erythropoietin + IV iron sucrose vs IV iron sucrose + IM placebo

• Interventions for treating iron deficiency anaemia in inflammatory bowel disease 2021 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 40 participants
  Very low

Oral ferric maltol vs oral placebo

It is very uncertain whether oral ferric maltol changes serious adverse events ‐ mild disease to quiescent (up to 52 weeks) compared with oral placebo (very low certainty).

• Interventions for treating iron deficiency anaemia in inflammatory bowel disease 2021 · Cochrane Headline outcomes only
  RR 1 [0.15, 6.88]
  1 study · 128 participants
  Very low