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Table 3 Summary of findings for IV-iron compared to oral iron for postpartum anemia

From: Intravenous iron versus blood transfusion for postpartum anemia: a systematic review and meta-analysis

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect (95% CI)

№ of participants (studies)

Certainty of the evidence (GRADE)

Comments

Risk with oral iron

Risk with IV Iron

Fatigue change score

–

SMD 0.4 lower (0.62 lower to 0.18 lower)

–

324 (2 RCTs)

⊕⊕OO Lowa,b

IV Iron may result in a slight reduction in Fatigue change score

Fatigue end-point

–

SMD 0.1 lower (0.31 lower to 0.12 higher)

–

329 (1 RCT)

⨁⨁OO Lowc,d

IV Iron may result in little to no difference in Fatigue end-point

Hemoglobin concentrations (change and endpoint scores): longest follow-up

The mean Hb levels (change and endpoint scores): longest follow-up was 11.5 g/dL

MD 0.54 g/dL higher (0.47 higher to 0.61 higher)

–

2901 (13 RCTs)

⊕⊕⊕O Moderatee

IV Iron likely results in an increase in Hb concentrations (change and endpoint scores): longest follow-up

Ferritin concentration (change and endpoint scores): longest follow-up

The mean ferritin concentration (change and endpoint scores): longest follow-up was 29.6 mcg/L

MD 58.07 mcg/L higher (55.74 higher to 60.41 higher)

–

3184 (12 RCTs)

⊕⊕O Moderatef

IV Iron likely results in an increase in ferritin concentration (change and endpoint scores): longest follow-up

Total drug-related adverse effects

222 per 1000

153 per 1000 (129 to 180)

RR 0.69 (0.58 to 0.81)

2603 (7 RCTs)

⊕⊕OO Lowg,h

The evidence suggests that IV iron reduces total drug-related AEs

All gastrointestinal disorders

159 per 1000

27 per 1000 (19 to 41)

RR 0.17 (0.12 to 0.26)

1915 (6 RCTs)

⊕⊕⊕⊕ Highi

IV iron results in fewer GI disorders than oral iron

Headache

16 per 1000

25 per 1000 (14 to 45)

RR 1.58 (0.86 to 2.83)

2214 (4 RCTs)

⊕⊕⊕ OO Moderatej

IV iron probably results in an increase in headaches

Dysgeusia (taste distortion)

0 per 1000

0 per 1000 (0 to 0)

RR 9.84 (2.71 to 35.75)

1839 (5 RCTs)

⊕⊕⊕⊕ Highk

IV iron results in a large increase in frequency of dysgeusia (taste distortion)

Musculoskeletal disorders, e.g., myalgia

4 per 1000

11 per 1000 (4 to 27)

RR 2.66 (1.05 to 6.75)

1211 (5 RCTs)

⊕⊕⊕ O Moderatel

IV iron likely results in an increase in musculoskeletal disorders

All injection site disorders-Injection site pain, bruising, swelling, irritation, burning, or reaction

1 per 1000

16 per 1000 (5 to 49)

RR 15.93 (5.04 to 50.36)

2140 (5 RCTs)

⊕⊕⊕ O Moderatel

IV iron results in large increase in injection site disorders

  1. CI confidence interval, MD mean difference, RR risk ratio, SMD standardized mean difference
  2. GRADE Working Group grades of evidence
  3. High certainty: we are very confident that the true effect lies close to that of the estimate of the effect
  4. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
  5. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
  6. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect
  7. Explanations
  8. aDowngraded one level because both studies unblinded, and unclear allocation concealment
  9. bDowngraded one level for precision because there were < 400 participants in the fatigue outcome, and both studies had varying off-protocol RBC-T use in each study arm
  10. cDowngraded one level because unblinded, and unclear allocation concealment
  11. dDowngraded one level for precision because there were < 400 participants in the fatigue outcome
  12. eDowngraded one level for inconsistency as I2 = 91% and different studies have different conclusions
  13. fDowngraded one level for inconsistency as I2 = 99%
  14. gWe downgraded one level because all 7 studies unblinded; it was unclear if allocation was concealed in 5/7 studies
  15. hDowngraded one level for inconsistency as I2 = 86% and different studies have different conclusions
  16. iWe downgraded one level because all 6 studies unblinded; allocation concealment was unclear for 4/6 studies
  17. jWe downgraded one level because unblinded, and unclear allocation concealment in all 4 studies
  18. kWe downgraded one level because all 5 studies unblinded; it was unclear if allocation was concealed in 4/5 studies
  19. lWe downgraded one level because all 5 studies unblinded and unclear allocation concealment
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Systematic Reviews

ISSN: 2046-4053