Three RCTs (333 participants, 46 to 196) were included in the review. Adequate randomisation was performed in all the trials. The allocation sequence was not concealed in one trial. The authors stated that there was no blinding of participants or study staff in any of the trials, although study personnel were blinded to treatment allocation in one trial. Two trials presented all the data. Risk of bias was judged to be low for one trials and high for two trials. All the trials received financial support from the manufacturers of intravenously administered iron replacement.
Administration of iron replacement therapy by the intravenous route was associated with significant benefits compared to oral administration with higher haemoglobin levels (WMD 6.8g/L, 95% CI 0.9 to 12.7; Ι²=80%), serum ferritin (WMD 109.7μg/L, 95% CI 5.37 to 214; Ι²=99%) and fewer instances of discontinuation due to side effects (OR 6.2, 95% CI 2.2 to 17.1; Ι²=0%). The authors stated that the significant statistical heterogeneity observed in the results may be due to variations in duration of iron replacement therapy and follow-up.
There were no significant differences between groups in quality of life scores and disease activity.