A discussion on “A selective review of statistical methods using calibration information from similar studies” by Qin, Liu and Li

We Qin, Liu and Li (QLL) on a thoughtful and much needed review of many interesting methods for combining information from similar studies. We appreciate being given the opportunity to make a discussion. QLL cover a variety of different settings and methods. Based on that, we will provide a brief review on some additional relevant literature with a focus on methods that deal with population heterogeneity, since it is most likely that different studies sample different and whether information be combined depends on how similar those among many other To the we will follow the setting in of QLL, most of methods more broadly applied.