What constitutes a significant change in NTproBNP level?
The NTproBNP assay has excellent precision. If we were to run the same sample once daily for many days, the variation in the results would be less than 10%. That is, a sample with a value of 1000 pg/mL would be measured as 900-1100 pg/mL. However, there’s a large amount of physiologic, intra-individual variation. As a result, many experts recommend that changes of less than 2-fold not be considered significant. In other words, if the levels have not doubled or halved, then it should not be considered a real change.
