What do systematic reviews say?

Intravenous iron vs oral iron

Intravenous iron therapy may leads to higher haemoglobin levels at end of preoperative treatment (g/dL) compared with oral iron therapy (low certainty).

• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  MD 1.23 [0.8, 1.65]
  2 studies · 172 participants
  Low
• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Iron therapy vs No treatment, placebo, usual care, or another oral care measure

Iron therapy showed no clear difference in haemoglobin levels at end of preoperative treatment (g/dL) compared with placebo, no treatment or standard care (low certainty).

• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  MD 0.63
  2 studies · 83 participants
  Low
• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  MD 0.17
  2 studies · 86 participants
  Low

Parenteral iron vs oral iron

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  6 studies · 769 participants
  Low

Oral iron vs inactive control

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 402 participants
  Very low

Parenteral iron vs inactive control

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  9 studies · 1371 participants
  Very low