Dear Editor,

I read with interest the recent meta-analysis by Chen et al. [1]. They have presented very useful data. However, I am interested to know if they considered age as a covariate in their supplementary analyses, for example, using metaregression. This is because the ages of the different study groups which they entered in their meta-analysis are different, with wide a range, causing a misinterpretation. Maybe patients with intestinal metaplasia and dysplasia are older than their control group. We know that if the age is increased, the chance of reducing gastric cancer may not decrease despite eradication of Helicobacter pylori [2]. So, this nonsignificant difference between patients with intestinal metaplasia and dysplasia and the control group may be due to an age difference and not merely due to these diseases themselves.