Assessment of the value of diagnostic indicators such as symptoms and laboratory tests
results from calculation of the sensitivity and specificity of the indicators. Knowledge of the
rate of occurrence of the disease allows for additional calculations of the error rates in using
an indicator. These calculations are accurate only when the data on which they are based
are reliable. If the diagnosis, which is used as the criterion for computing the sensitivity and
specificity, is not accurate, then the resulting calculations will be in error. We show how a …

We were interested to see an application of latent class analysis (LCA) in a recent issue of
this journal. Rindskopf and Rindskopf gave an exposition of LCA in the context of a 24 table
of frequencies of patients showing or not showing each of four indicators of myocardial
infarction. LCA has grown greatly in popularity in recent years; it certainly provides an
elegant and natural way of generalizing the independence model for frequencies in a
multidimensional contingency table so as to account for associations between the variables …