Question

All of the following are true of odds ratio EXCEPT: (3pts)

It is an estimate of relative risk

It is the only measure of risk that can be obtained directly form a case-control study

It is the ratio of incidence in exposed divided by incidence in non-exposed.

It can be calculated without data on rates (as in a case-control study).

Answer 1

Odds ratio can be approximately taken as an estimate of Relative risk it is also the only measure of risk. Thus, first and second statement is true.

Now,

The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure.

Therefore, since it's a ratio of two odds and not just ratio of incidence in exposed and non exposed, the third statement appears to be false.

Odds ratio does not require any data regarding the rate of occurrence. Hence, the forth statement is correct.

**All statements are true except the third one.**