title: Biological variation and reference change values: an essential piece of the puzzle of laboratory testing.
authors.forename: Mario
authors.initials: M
authors.lastname: Plebani
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
mesh_terms: D001826:Body Fluids / Q000737:chemistry; D019963:Clinical Chemistry Tests / Q000592:standards* / Q000706:statistics & numerical data / Q000639:trends; D006801:Humans; D012016:Reference Values