1·Whereas some of the low self-control study members are more likely to be single parents with a very low income and the parent is in poor health and likely to be a heavy substance abuser.
然而，一些自我控制能力低的研究对象更有可能是收入非常低的单亲父母，父母的健康状况很差，很可能是重度药物滥用者。
2·Methods: A nested case-control study.
方法：采用成组病例对照研究。
3·Methods: Prospective, double-blind control study.
方法：前瞻性、双盲对照研究。
4·Methods The randomized control study was performed.
方法采用同期非随机对照试验。
5·A case control study nested in cohort was conducted.
本文进行了一项队列内病例对照研究。
6·Neural tube defects; Case control study; Risk factors.
神经管畸形；病例对照研究；危险因素。
7·Methods 1: m matched case-control study was conducted.
方法采取1：M匹配的病例对照研究。
8·Methods a community based case control study was designed.
方法以社区为基础的病例对照研究。
9·Methods Cross-sectional study and case-control study were performed.
方法现况调查和病例对照研究。
10·DESIGN: Prospective case control study based on experimental animals.
设计：以实验动物为研究对象，前瞻性、对照研究。