What do systematic reviews say?

Intravenous iron vs placebo

It is very uncertain whether intravenous iron changes mild adverse effects compared with placebo (very low certainty).

• Intravenous iron therapy for non‐anaemic, iron‐deficient adults 2019 · Cochrane Headline outcomes only
  RR 1.19 [0.97, 1.45]
  3 studies · 440 participants
  Very low

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 inactive control

• Iron therapy in anaemic adults without chronic kidney disease 2014 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 1629 participants
  Very low

Parenteral iron vs inactive control

It is very uncertain whether parenteral 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 1 [0.74, 1.34]
  7 studies · 1802 participants
  Very low

Parenteral iron vs inactive control

It is very uncertain whether parenteral 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 1.04 [0.63, 1.69]
  10 studies · 2141 participants
  Very low

Parenteral iron vs inactive control

It is very uncertain whether parenteral 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 0.84 [0.66, 1.06]
  8 studies · 1315 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