Table 3

Effects of misclassification on prevalence and OR estimates in two hypothetical examples

Level of histological misclassification
0% (no error)10%15%
A. Observed prevalences of p53 immunohistochemistry-positive tumors by histological type
Intestinal-type cancer60%57%56%
Diffuse-type cancer30%33%35%
Difference30%24%21%
B. Observed ORs for H. pylori infection and gastric cancer risk by histological type
Intestinal-type cancer5.05.46.0
Diffuse-type cancer10.08.97.7
Ratio of the two ORs2.01.61.3