洗腎患者主動和被動的注射補充鐵劑差別

在英國2100位洗腎患者，給予主動和被動的注射補充鐵劑，追蹤2年，有差別嗎？
https://www.nejm.org/doi/full/10.1056/NEJMoa1810742

之前的教育是認為，當洗腎患者貧血合併鐵質不夠時，才補充鐵劑，之所以如此被動補充鐵劑是因為擔心它的副作用，感染。然而事實真是如嗎？

實驗採取：prospective, randomized, open-label, blinded end-point, 分成2組

組1) High-dose group: 400 mg of iron sucrose per month, to be administered intravenously, was prescribed to the patients, with safety cutoff limits (ferritin concentration of 700 μg per liter or a transferrin saturation of 40%) (每個月主動補充鐵劑，超過cutoff limit就暫停注射鐵劑，等抽血數值下降再繼續）

組2) Low-dose group received a monthly dose of 0 mg to 400 mg of iron sucrose as required to maintain a minimum target ferritin concentration of 200 μg per liter and a transferrin saturation of 20%, in line with accepted clinical guidelines. （目前的guideline：當鐵質不夠時，ferritin 少於 200 and transferrin saturation 少於 20%才被動補充鐵劑）

結果： 
1) High-dose group needed fewer blood transfusions and received lower doses of erythropoiesis-stimulating agents (ESA). 
2) Infection rates did not differ between the groups. 

註：看起來是好事，主動補充鐵劑組有較少輸血的機會，也使用較少量的ESA，在這2年的觀察也沒有較高的感染機會。High dose組相對於現今gulideline支持的low dose組，算是noninferior！