Evaluating interrater agreement through "case-control" sampling

An approach to evaluating interrater agreement is presented that is based on "case-control" sampling scheme, in which individuals are classified by one rating method and stratified prior to being classified by a second rating method. A new estimate of the kappa interrater agreement index that is based on the case-control scheme is also presented. Power and other economic considerations are discussed, indicating that the new approach may be useful in practice.