不同组的样本数差异比较大，然后审稿人就提出疑问 How did the authors adjust their analysis given that vast majority of their study subjects (1059 out of 1282) were patients without DR, and only small number of patients had any DR and, in particular, only 36 patients had severe DR. This might lead to significant bias.

如何回答或者解决这个问题