Analytical variation in metabolic profile testing
Summary Results are presented demonstrating quality control of the analytical procedures used during the application of metabolic profile tests to dairy herds over a period of 3 years. The significance of analytical variance is discussed in relation to the average population variance in dairy herds. It is concluded that analytical variance can be restricted to reasonable proportions providing that careful quality control is continuously employed.
Accuracy in clinical chemistry.
Improved accuracy of clinical laboratory measurements requires a broad range concept of quality control. Items considered include standardization, precision, specificity, recovery studies, interlaboratory comparisons, and long-range stability of laboratory performance.
Medical Implications of Quality Control in Clinical Biochemistry
laboratory surveys (e.g. Belk and Sunderman, 1947; Wootton and King, 1953; Tonks, 1963); they can also demonstrate local lack of reliability all too readily by submitting the same specimen to a laboratory under two different names. Imprecision in chemical work exists particularly when analyses are performed singly (or at most in duplicate), as is the usual practice in overworked clinical biochemistry laboratories. It may sometimes appear a disadvantage to clinical biochemists that they should work in laboratories that can have their analytical shortcomings objectively displayed, but at least they have the opportunity-by means of quality control programmes-to define the degree of confidence that medical staff can place upon the results of their observations. This is in sharp contrast to many essentially qualitative aspects of the art of medicine, some of which can only have their correctness confirmed at operation or at autopsy, and it is for the laboratory to prove that the clinical state of patients is no longer the best method for detecting errors in laboratory performance, as was suggested by Peenen and Lindberg (1965). This attitude should nowadays be as dangerous as it is unsound, since it takes insufficient account of the fact that most clinical biochemistry laboratories operate programmes of quality control; furthermore, it implies that the clinical state of the patient can be used as the justification for rejecting laboratory results even though the patient's condition had originally presented a problem in diagnosis or management that required investigation by chemical methods for its solution.