Study Design. Randomized controlled trial.

研究设计：随机对照试验。

Study Design. A randomized controlled trial.

研究设计：随机对照试验。

METHODS: a randomized controlled trial was adopted.

方法：采用随机对照试验。

DESIGN: Examiner blinded non randomized controlled trial.

设计：单盲非随机的对照试验。

Study Design. A prospective, randomized controlled trial.

前瞻性的随机对照研究。