PROPOV-K: a FORTRAN program for computing a kappa coefficient using a proportional overlap procedure

The computer program PROPOV-K allows the computation of an unweighted kappa coefficient for expressing interrater agreement in the general case in which multiple raters (not necessarily fixed in number) formulate a variable number of multiple diagnoses for each subject. PROPOV-K assesses agreement among lists of multiple diagnoses composed of nonordered categories. PROPOV-K calculates a kappa coefficient on the basis of estimating proportion of agreement between two diagnostic formulations as the ratio of the number of agreements between specific categories over the number of different specific categories mentioned in the two diagnostic lists. When multiple raters formulate a variable number of multiple diagnoses for each subject, the use of a kappa coefficient has been limited to researchers since there are no generally available computer programs. The purpose of this paper is to present a FORTRAN computer program allowing the computation of a kappa coefficient for the case mentioned above and to illustrate its use with examples respectively involving multiple psychiatric and multiple physical diagnoses.