设计：随机双盲法观察。
很少有实验报道随机取样的方法。内含的试验方法的质量一般很弱。三种试验分别为随机取样、双盲法、安慰剂给样试验。
The methodological quality of included trials was generally "poor." Few trials reported methods of randomization. Three trials were randomized, double blind, and placebo-controlled.
方法：采取随机双盲对照观察法。
这一实验采取的是随机法和双盲法，294个婴儿吸入笑气，288个婴儿用的是安慰剂。
The trial was randomized and double-blinded, with 294 infants receiving inhaled nitric oxide and 288 receiving a placebo.
方法随机双盲对照法补锌干预研究。
Methods The effects of zinc supplementation were assessed in a double-blinded randomized control design.
入院接受密集化疗的血液学恶性肿瘤的病人被随机分为两组，在单中心实验中用双盲法处理安慰剂组和控制组。
Patients with haematological malignancies receiving intensive chemotherapy and requiring hospitalization were randomized in a double-blind, placebo-controlled single-centre trial.
方法采用双盲随机对比法，共收治恶性疟患者151例，其中蒿甲醚为50例，本芴醇为51例，复方蒿甲醚为50例。
Methods Of 151 patients, 50 patients were treated with artemether , 51 patients were treated with benflumetol and 50 patients were treated with combined regime(co-artemether).
方法采用双盲随机对比法，共收治恶性疟患者151例，其中蒿甲醚为50例，本芴醇为51例，复方蒿甲醚为50例。
Methods Of 151 patients, 50 patients were treated with artemether , 51 patients were treated with benflumetol and 50 patients were treated with combined regime(co-artemether).
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