2013 Volume 40 Issue 2 Pages 89-95
The reliability of the reference value of a clinical test is lowered if the sample size of the study data was not sufficient. The purpose of this study was to indicate the reliability of the reference value by displaying not only the point estimate, but also the interval estimate. The rest electrocardiograms of 1276 cases of healthy Japanese men were used for the present study. To set the upper limit of the QT reference value, we used the bootstrap method. As we supposed beforehand,the range of confidence interval widened in both extremes of RR where the sufficient number of study cases could not be collected. As we showed in this study, the upper limit of reference value (the parameter in the upper tail of distribution) could be comparatively easily estimated with the confidence interval by using the bootstrap method.
