For the laboratory medicine, it's critical to understand difference between Reference Interval (RI) and Biological variation (BV). Westgard is pleased to have a guest essay where the most commonly-asked-questions about both topics are answered.
The reference intervals as well as the components of biological variation can together play an important role in medical laboratory to notify doctors about changes in patient status. Therefore, in our opinion the future laboratory information system should not only concerned on the significant changes of patient result compared to the reference interval but also to utilise different indices of biological variation so it can compare the current test result with the previous one (expressed as RCV value).
Frequently-Asked-Questions on Reference Intervals and Biological Variation