Traditional methods of computing standardized mortality ratios (SMR) in mortality studies rely upon a number of conventional statistical propositions to estimate confidence intervals for obtained values. Those propositions include a common but arbitrary choice of the confidence level and the assumption that observed number of deaths in the test sample is a purely random quantity. The latter ass...

A stratified version of nested case-control sampling which we call "countermatching" is presented. This design uses data available for all cohort members to obtain a sample for collecting additional information in a case-control substudy. Hitherto the only stratified sampling design for such studies has involved matching of controls to cases with respect to confounding variables. However, in so...

The optimal allocation of available resources is the concern of every investigator in choosing a study design. The recent development of statistical methods for the analysis of two-stage data makes these study designs attractive for their economy and efficiency. However, little work has been done on deriving two-stage designs that are optimal under the kinds of constraints encountered in practi...