What do systematic reviews say?

Oral iron vs inactive control

It is very uncertain whether oral iron changes mortality compared with inactive control (very low certainty).

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  RR 1.05 [0.68, 1.61]
  4 studies · 659 participants
  Very low

Oral iron vs inactive control

It is very uncertain whether oral iron changes proportion requiring blood transfusion compared with inactive control (very low certainty).

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  RR 0.74 [0.55, 0.99]
  3 studies · 546 participants
  Very low

Oral iron vs inactive control

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 300 participants
  Very 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

Oral iron vs inactive control

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 276 participants
  Very low

Oral iron vs inactive control

It is very uncertain whether oral iron changes serious adverse events compared with inactive control (very low certainty).

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  RR 0.96 [0.76, 1.22]
  5 studies · 731 participants
  Very low

Parenteral iron vs oral iron

It is very uncertain whether parenteral iron changes mortality compared with oral iron (very low certainty).

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  RR 1.49 [0.56, 3.94]
  6 studies · 1009 participants
  Very low

Parenteral iron vs oral iron

It is very uncertain whether parenteral iron changes proportion requiring blood transfusion compared with oral iron (very low certainty).

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  RR 0.61 [0.24, 1.58]
  2 studies · 371 participants
  Very low

Parenteral iron vs oral iron

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 44 participants
  Very 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

Parenteral iron vs oral iron

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 771 participants
  Very low

Parenteral iron vs oral iron

It is very uncertain whether parenteral iron changes serious adverse events compared with oral iron (very low certainty).

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  RR 1.23 [0.99, 1.54]
  7 studies · 1100 participants
  Very low

Intravenous iron vs oral iron

Intravenous iron therapy may leads to higher ferritin preoperatively postintervention (ng/L) compared with oral iron therapy (low certainty).

• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  MD 395.03 [227.72, 562.35]
  2 studies · 151 participants
  Low

Intravenous iron vs oral iron

The review found no eligible studies for this question.

• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Intravenous iron vs oral iron

The review found no eligible studies for this question.

• Iron therapy for preoperative anaemia 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

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

Intervention not reported

The intervention probably leads to lower low Hb deferral ‐ at first donation visit after commencement of… (moderate certainty).

• Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors 2014 · Cochrane Headline outcomes only
  RR 0.34 [0.21, 0.55]
  4 studies · 1194 participants
  Moderate

Intervention not reported

The intervention probably leads to lower low Hb deferral ‐ after multiple donation visits (moderate certainty).

• Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors 2014 · Cochrane Headline outcomes only
  RR 0.25 [0.15, 0.41]
  3 studies · 793 participants
  Moderate

Intervention not reported

• Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors 2014 · Cochrane Headline outcomes only
  no estimate extracted
  8 studies · 847 participants
  Moderate

Intervention not reported

• Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors 2014 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 406 participants
  Moderate