You'll see that term a lot.

我们将会经常遇到这个概念
Relative risk of death is an interesting concept from public health.

死亡相对危险度是个源于公共健康的概念
What this does, when you use relative risk

当运用相对危险度这个概念时
you take some group of the population

要选定一个群组
and you establish their risk as--at one.

并把这个群组的风险设为1
You just say that arbitrarily this group, the reference group,

可以随意地设定一个群组作为参照组
let's say the group with the lowest weights,

我们可以假设是体重最低的一组
or the lowest cholesterol or anything,

或者胆固醇水平最低的一组或者其他
you say their risk is one, and then you look to see

将参照组的风险设为1
how everybody else's risk is compared to that.

然后就可以比较参照组与其他组的风险
If some group, let's say you have cholesterol of two hundred

比如说有一个组胆固醇水平200
and your relative risk is established at one, and then

相对风险设为1