Greenland S
Int J Epidemiol. 1985 Mar;14(1):130-4. doi: 10.1093/ije/14.1.130.
In a control-initiated study the investigator begins with existing data on a non-diseased group and then selects cases to obtain comparison data; thus the usual order of case and control selection is reversed. This paper discusses the parallels and differences between control-initiated studies and more traditional case-control designs. Special attention is given to problems of selection bias and matching. A sample-size formula for control-initiated studies is also provided.
在一项由对照启动的研究中，研究者从非患病组的现有数据入手，然后选择病例以获取比较数据；因此，病例和对照选择的通常顺序被颠倒了。本文讨论了由对照启动的研究与更传统的病例对照设计之间的异同。特别关注选择偏倚和匹配问题。还提供了一个用于由对照启动的研究的样本量公式。
