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Comparison of quality-control rules used in clinical chemistry laboratories

, : Comparison of quality-control rules used in clinical chemistry laboratories. Clinical Chemistry 39(8): 1638-1649

Numerous papers have been written to show which combinations of Shewhart-type quality-control charts are optimal for detecting systematic shifts in the mean response of a process, increases in the random error of a process, and linear drift effects in the mean response across the assay batch. One paper by Westgard et al. (Clin Chem 1977;23:1857-67) especially seems to have attracted the attention of users. Here we derive detailed results that enable the characteristics of the various Shewhart-type control schemes, including the multirule scheme (Clin Chem 1981;27:493-501), to be calculated and show that a fundamental formula proposed by Westgard et al. in the earlier paper is in error, although their derived results are not seriously wrong. We also show that, from a practical point of view, a suitably chosen Cusum scheme is near optimal for all the types and combinations of errors discussed, thereby removing the selection problem for the user.


PMID: 8353950

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Cammell, S.B.; Sutton, J.D.; Beever, D.E.; Humphries, D.J.; Phipps, R.H., 2000: The effect of crop maturity on the nutritional value of maize silage for lactating dairy cows. 1. Energy and nitrogen utilization. Four multiparous Holstein-Friesian cows fitted with simple cannulas in the proximal duodenum and the rumen were offered four diets in a 4 X 4 Latin-square design to evaluate the effect on energy and nitrogen balance of crop maturity of maize when...

Warren, J.C.R.; Fuller, J.C.E., 1955: Experimental herbicide 3Y9. An account of limited field trials, extending over one season only, with 3Y9 - tris (2, 4-dichlorophenoxyethyl) phosphite. It is reported to kill the following weeds when applied pre-em. at 2-8 lb active ingredient/ac: crab grass, stink grass, bar...

Nitz R.E.; Resag K., 1968: Pharmacological studies of the new carbocromene new coronary dilatator of selective and prolonged action. Ars Medici (Edition Francaise) 23(5): 645-653

Teras, I., 1976: Bumble bees bombus hymenoptera apidae on red clover in south savo finland. The visits of bumblebees to red clover were studied in 1972-1974, and the results compared with the observations made at the same place (, in 1960-1966. The numbers of bumblebee individuals varied a great deal during the su...

Baserga, R., 1978: Resting cells and the G1 phase of the cell cycle. Journal of Cellular Physiology 95(3): 377-382

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Raubeson Linda A.; Gensel Patricia G., 1986: Conifers of the Upper Cretaceous Black Creek Formation; a preliminary report. American Journal of Botany: , Pages 716. 1986.

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