Figure 5.

Comparison of confidence intervals of means derived from selected previous studies with the reference intervals determined in the current study. Gray fields indicate missing data or data that cannot be compared (for example, use of different test kits). White fields indicate that the confidence interval of mean of the previous study is situated within our reference interval and includes our median value. Light shades show that the previously published confidence interval lies within our reference interval but is above (pink) or below (blue) our median value. Intermediate shades indicate that the earlier confidence interval partly overlaps our reference interval and includes the upper (pink) or lower (blue) border of our reference interval. Dark shades mark previous confidence intervals that fall entirely above (pink) or below (blue) the reference interval reported in the current study.