Epidemiological study on screening test of semi-health condition in young adults

INTRODUCTION: The purpose of the present study was to examine a screening test for semi-health condition which evaluated a level of dynamic state in the susceptibility phase based on the natural history of disease.  We have reported on findings about the semi-health index elsewhere.  In this study, we discussed on a sensitivity, specificity, positive predictive value, negative predictive value, and prevalence derived from a screening test for semi-health symptoms among young adults in Japan. 

METHODS: The self-report questionnaire, which consisted of 53 items, was administered to 2,074 young adults in Japan between 2011 and 2012.  

RESULTS:  A principal components analysis was applied to the valid data in order to extract indices which evaluated structural characteristics on semi-health condition.  By this analysis, four principal components were extracted.  Especially, the first principal component was extracted as an index which indicated a quantitative aspect of the semi-health condition.  Every eigenvector of its component had a mark of plus.  Therefore, this component was used as the semi-health index.  Furthermore, a distribution of young adults with semi-health symptoms was determined by using this index.  The sensitivity, specificity, positive predictive value, negative predictive value indicated 88.9%, 84.2%, 46.0%, and 98.1%, respectively.  The prevalence of the semi-health condition was 13.1%.    

CONCLUSIONS: Epidemiological indices from the screening test will show an excellent level of discriminating the semi-health from good health state.  The receiver operating characteristic curve derived from sensitivity and specificity will be also in a good level.