Skip to main content
Fig. 1 | BMC Medical Research Methodology

Fig. 1

From: The effect of disease misclassification on the ability to detect a gene-environment interaction: implications of the specificity of case definitions for research on Gulf War illness

Fig. 1

Venn diagrams showing the overlap of GWI case definitions. A Overlap of the 3 most used GWI case definitions and their subtypes and variants. The various areas are approximately proportional to their estimated prevalence in the Gulf War-deployed U.S. military population, estimated by applying survey weights to the USMHS deployed sample data (n = 6,497) and quantified by the given percentages. B Overlap of the Research and CDC case definitions showing that the cases identified by the CDC case definition are composed of 3 zones: true positive cases where Research and CDC agree (e), true positive cases missed by Research (Research false negative cases) (f), and CDC false positive cases (g). Note that as the number of CDC false positive cases increases, the number of Research false negative cases decreases. The number of controls was constant and did not change with corrections for disease misclassification. The Modified Kansas without exclusions case definition (not pictured) is interchangeable with the CDC case definition in (B). Abbreviations: FN, false negative; FP, false positive; TP, true positive

Back to article page

BMC Medical Research Methodology

ISSN: 1471-2288

Contact us