Table 1. Expert inter-reader variability of chest radiographic interpretations.

Expert reader interpretation*	Agreement	Kappa statistic	Asymptotic standard error (ASE)
Disease type (“typical” vs “atypical”)	Substantial	0.660	0.082
Presence or absence of cavitation	Substantial	0.749	0.067
Presence or absence of upper lung zone disease	Substantial	0.643	0.097
Presence or absence of volume loss	Fair	0.352	0.074
Presence or absence of acinar shadows	Fair	0.257	0.059

*See text for definition of terms.