Internal Quality Control of Radioimmunoassays: Monitoring of Error

Abstract

A cumulative sum technique has been specially designed to monitor the error between replicate determinations made on quality control plasma for consecutive batches of assays. This procedure has played a vital role in assessing assay performance. Special consideration has been given to small sample sizes (n = 2 or 3) which is generally the rule rather than the exception in many situations. This technique has been applied to numerous steroid radioimmunoassays and has ensured that both the mean value and the standard error of hormone levels of a quality control pool were under control. Data from routine assays of oestriol and testosterone in plasma from women are presented. Since this technique provides a sensitive measure of monitoring error, it assists the endocrinologist in elucidating statistical inferences which are a manifestation of assay performance.

A Diffusion Process and Its Applications to Detecting a Change in the Drift of Brownian Motion

“…A particularly interesting article on the applied use of cusum stopping rules is by Wilson et al (1979). In order to control the quality of radioimmunoassays, plasmas of known composition are occasionally submitted to be assayed, with the result regarded as a normal random variable with unknown mean and variance.…”

“…To obtain a Page like process, it is possible to run simultaneous cusum procedures (Wilson et al, 1979) or use the method of mixtures (Pollak & Siegmund, 1975 4, and the basic theory is much as in the one-dimensional case.…”

“…Interesting applications are discussed by Wilson et al (1979) and Weatherall & Haskey (1976). We seek a stopping rule T which 'detects' the change point v 'as soon as possible'.…”

Exploitation des contrôles de qualité

“…Dans la description de cette méthode, Wilson [13] conclut lui aussi qu'il s'agit d'une technique facile et rapide, sans calculs statistiques compliqués, mais reposant sur une théo-rie qui reste assez complexe.…”

Progesterone Assays: Guidelines for the Provision of a Clinical Biochemistry Service

“…Cumulative sum techniques't': 44,47 can also be employed to monitor drift in serum QC pools providing important criteria for assessing …”