Measurement of inaccuracy and imprecision of HCG methods using dilutions of the WHO 4th IS-HCG standard and a pregnant patient's serum.

Introduction: Differences in human chorionic gonadotropin (hCG) results obtained by seven different methods were documented by analyzing dilutions of the WHO 4th International Standard (IS) and a pregnant patient's serum.

Materials And Methods: Biases of +30.9 to -37.

Unique approach to derivation of random error in laboratory assays: application to glycohemoglobin testing demonstrates poor clinical performance for immunochemistry assay.

The measurement of glycohemoglobin is the best measure of mean glucose within a 3-4 month range. As it is used for patient education, counseling, feedback control, and ultimately for patient motivation, its measurement should be optimally accurate and precise. Duplicate hemoglobin A1c readings were used to determine physiological (changes over time between measurements) and analytic variation of two widely used laboratory assays: Bio-Rad Variant II's high-performance liquid chromatography (HPLC) system and Roche's immunoassay.