What are relative risk, number needed to treat and odds ratio?

Relative Risk, Odds Ratio, Attributable Risk and Number Needed to Treat

The research may or may not be epidemiological but there is a high likelihood that it would use the epidemiological indices discussed in this note. Rate, risk, hazard, incidence, and prevalence are everyday indices of disease occurrence that are used in a large number of research endeavours. Although these indices apparently look simple but many researchers are not fully comfortable in their us...

Odds Ratio, Hazard Ratio and Relative Risk

Odds ratio (OR) is a statistic commonly encountered in professional or scientific medical literature. Most readers perceive it as relative risk (RR), although most of them do not know why that would be true. But since such perception is mostly correct, there is nothing (or almost nothing) wrong with that. It is nevertheless useful to be reminded now and then what is the relation between the rel...

Number Needed to Treat

Number needed to treat (NNT); number needed to harm (NNH).

Number needed to treat and baseline risks.