Question

You explained very well the definitions, uses and differences of OR and RR. Which type of studies benefit better from each? Also, can you please explain the odds ratio in terms of correlation?

Answer 1

Odds ratio:

Odds ratio measure the association between exposure and outcome.

Relative risk or risk ratio:

Risk ratio is a probability of outcome of an Exposed group to the probability of an unexposed groups.

Uses:

Odds ratio:

It helps to determine the risk factor.

It helps in compare the magnitude of many risk factors.

Risk ratio:

Its descriptive statistics.

It help to compare the risk factors of two groups.

Difference:

Odds ratio	Risk ratio
Needs incident of disease to calculate.	incident of the disease is not necessary.
Usually prospective studies.	Retrospective studies.
Demonstrates temporality.	Can over estimates the risk in rare disease.

What type of studies get benefits:

Odds ratio:

Prospective studies

Cross sectional studies

Clinical trail

Risk ratio:

Retrospective studies

Cross sectional studies.

Odds ratio in correlation:

Odds ratio 1 indicates condition or event under study equally occurs in both groups.

Odds ratio greater than 1 indicates condition or events more likely to occur in first group.