Abstract
Laboratory tests are used for diagnosis, treatment, and prognostic evaluation of diseases; however, the reference values used are obtained from populations. Therefore, abnormal changes tend to be overlooked when the changes are small, or detailed examinations tend to be recommended in excess when laboratory values exceed the reference values on health check-ups and so on. In this study, we obtained individually-based reference values from consecutive laboratory tests and examined whether subtle changes could be detected. The results suggest that the use of individuallybased reference values would allow the detection of abnormalities not detectable when populationbased reference values are used; thus, we consider individually-based reference values to be more useful in making judgments than population-based reference values. The prerequisite for obtaining individually-based reference values is to obtain consecutive laboratory values using the same measurement methods. In fact, however, laboratory tests are usually performed at different facilities, making it impossible to perform these tests uniformly. In order to calculate individually-based reference values based on consecutive laboratory test values properly, we believe it is necessary, in addition to internal accuracy control or the external accuracy control review currently performed at participating individual facilities, to ensure laboratory values by obtaining ISO15189 and to provide more stable laboratory values.
