title: Rate and delta checks compared for selected chemistry tests.
abstract: We compared delta and "rate" check methods for 12 selected chemistry tests. Rate checks were determined by dividing delta checks by inter-specimen interval time. The delta and rate check methods were based on differences and percent change of untransformed and absolute value-transformed values. The distribution of delta differences was not symmetrical for calcium, alkaline phosphatase, aspartate aminotransferase, or phosphorus, which led to different check limits between untransformed and absolute value-transformed methods. The dispersion of rate checks was large. The interval time between two consecutive tests was multimodal, which probably reflected adherence to fixed testing protocols.
authors.affiliation: Department of Pathology, Medical College of Ohio, Toledo 43699.
authors.forename: D A
authors.initials: DA
authors.lastname: Lacher
authors.forename: D P
authors.initials: DP
authors.lastname: Connelly
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D002118:Calcium / Q000097:blood; D002624:Chemistry, Clinical / Q000592:standards*; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D010758:Phosphorus / Q000097:blood; D011786:Quality Control; D013048:Specimen Handling; D013997:Time Factors
chemical_list: D010758:Phosphorus; D001219:Aspartate Aminotransferases; D000469:Alkaline Phosphatase; D002118:Calcium