[Skip to Navigation]
May 1988

A Partial Solution to the Base Rate Problem of the k Statistic

Author Affiliations

Clinical Research Unit for Anxiety Disorders University of NSW at St Vincent's Hospital 299 Forbes Street, Darlinghurst NSW, 2010, Australia
Rivendell Adolescent Unit Royal Prince Alfred Hospital Hospital Road, Concord, NSW, 2138 Australia

Arch Gen Psychiatry. 1988;45(5):504-505. doi:10.1001/archpsyc.1988.01800290126019

To the Editor.—  Recently there has been a dispute among experts concerning the measurement of diagnostic agreement1-3 and the use of the k statistic.4 We share the view of Uebersax5 that the real solution to this problem will require new paradigms for assessing interjudge agreement, and in particular that the more expensive multiple-judge designs or criteriondiagnosis designs are desirable. However, we do not accept that developing correction formulas to equate k values obtained from samples with different base rates is pointless.2,5 Under the conventional models for psychiatric diagnosis that underlie the calculation of k, it is possible to adjust k so as to incorporate base rate differences. This adjustment does not address the more complex issues raised,1,2,5 but may go some way toward reconciling divergent views2,3 about k.Following Spitznagel and Helzer,1 we define the sensitivity of a judge as the probability of

Add or change institution