Reference value of old people's hematocrit and geographical factors

This paper is written in order to provide a scientific basis for a unified standard of the reference value of Chinese healthy old people's hematocrit. It studies the relationship between the reference values of healthy old people's hematocrit, tested according to the Wintrobe Laws and five geographical factors. It is found that the altitude is the most important factor affecting the reference value of old people's hematocrit. As the altitude gradually increases, the reference value of their hematocrit also increases, the relationship is quite significant. By using the method of stepwise regression analysis, two multivariate regression equations are deduced:1=50.2+0.00248X1-0.0534X3-0.388X4+0.00383X5±2.2, 2=44.5+0.00231X1-0.0600X3-0.260X4+0.00341X5±2.1. If the geographical index values in a particular area in China are known, the reference value of old people's hematocrit in this area can be established by means of the regression equations. Furthermore, according to the dependent relationship of the reference value of old people's hematocrit on geographical factors, China can be divided into six regions: Qinghai-Tibet, Plateau, Southwest, Northwest, Southeast, North and Northeast.