1.
BMJ
; 323(7322): 1188, 2001 Nov 17.
Article
in English
| MEDLINE
| ID: mdl-11711421
2.
Stat Med
; 19(5): 723-41, 2000 Mar 15.
Article
in English
| MEDLINE
| ID: mdl-10700742
ABSTRACT
Cohen's kappa statistic is a very well known measure of agreement between two raters with respect to a dichotomous outcome. Several expressions for its asymptotic variance have been derived and the normal approximation to its distribution has been used to construct confidence intervals. However, information on the accuracy of these normal-approximation confidence intervals is not comprehensive. Under the common correlation model for dichotomous data, we evaluate 95 per cent lower confidence bounds constructed using four asymptotic variance expressions. Exact computation, rather than simulation is employed. Specific conditions under which the use of asymptotic variance formulae is reasonable are determined.