Standardization of Risk Ratios

Miettinen, O. S. (Harvard School of Public Health, Boston, Mass. 02115). Standardization of risk ratios. Am J Epidemiol 96: 383–388, 1972. The procedure commonly employed for the computation of “standardized” risk ratio estimates (observed-to-“expected” ratios) which characterize different categories of a risk factor do not lead to a set of mutually comparable values. In cohort studies truly standardized risk ratios can be obtained through a simple modification of the prevailing method. The problem is more subtle in case-control studies, but these studies, too, permit the computation of standardized risk ratio estimates with explicit specification of the standard.