What does RRS stand for?

Relative Risk

The ratio of the risk of disease or death among the exposed to the risk among the unexposed; this usage is synonymous with risk ratio; alternatively, the ratio of the cumulative incidence rate in the exposed to the cumulative incidence rate in the unexposed, i.e., the cumulative incidence ratio, and the term ``relative risk'' has also been used synonymously with ``odds ratio'' and, in some biostatistical articles, has been used for the ratio of forces of morbidity.