在文章里面看到的。
说什么logistic回归调整主效应和协变量。。。
调整协变量我懂什么意思。。
那么调整主效应是什么意思呢？？？？

原句是什么写的：
The null hypothesis is that OR=1 or, equivalently, beta=0, where OR refers to the odds ratio of individuals with a genotype cj versus the rest of individuals. This association test can be nonparametric (chi-squared test) or parametric (logistic regression) and, in this case, adjustment for main and confounders effects can be performed.

什么叫“adjustment for main effects”哇？