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Fig. 2 | BMC Medical Research Methodology

Fig. 2

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. 2

Association of the GWI number/severity score with case definitions and health-related quality of life. A Frequency distribution of the GWI number/severity score of 6,497 USMHS deployed veterans meeting the various GWI case definitions. Each line represents the score’s distribution in veterans classified as having GWI by one of the 5 case definitions and the control group of veterans who satisfied none of the case definitions. B-C, Association of the GWI number/ severity score with the SF-12 Mental Component Summary scores (r = -0.054 ± 0.002) (B) and Physical Component Summary scores (r = -0.064 ± 0.002) (C). The GWI number/severity score is an overall measure of the symptoms used to generate the Modified Kansas case definitions. Veterans rated each of the symptoms as absent (0), mild (1), or moderate or severe (2), and a veteran’s number/severity score was formed by summing these ratings over all the symptoms. A score of 0 on an SF-12 summary scale indicates the lowest health-related quality of life, while 100 indicates the highest. Associations of individual case definitions with the SF-12 scores are given in Figure S3 and Table S5

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BMC Medical Research Methodology

ISSN: 1471-2288

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