Objective analytical goals for interference in clinical biochemical methods have not yet been advocated. We propose that, since total analytical error is ideally less than half the within-subject biological coefficient of variation (CV1), the maximum allowable systematic error produced by an interferent (I) is:
where CVA is the relevant experimental analytical imprecision and SE is the systematic error. Such a goal may be applicable also to non-specificity, matrix effects and carryover.
International Federation of Clinical Chemistry. Approved recommendations on quality control in clinical chemistry. Part 1. General principles and terminology. Clin Chim Acta1979; 98: 129F–43F.
2.
International Federation of Clinical Chemistry. Drug effects in clinical chemistry. Part 2. Guidelines for evaluation of analytical interference. J Clin Chem Clin Biochem1984; 22: 275–9.
3.
International Union of Pure and Applied Chemistry. Definition and classification of interferences in analytical procedures. Pure Appl Chem1989; 61: 91–5.
4.
Societé Française de Biologie Clinique. Lignes directrices pour l'etude et la definition d'une interference analytique. Proposition d'un protocole. Ann Biol Clin1984; 42: 137–44.
5.
National Committee for Clinical Laboratory Standards. Interference testing in clinical chemistry; Proposed guideline. NCCLS Publication EP7-P. Villanova, PA: NCCLS, 1986.
6.
WestgardJOCareyRNWoldS. Criteria for judging precision and accuracy in method development and evaluation. Clin Chem1974; 20: 825–33.
7.
PetersTWestgardJO. Evaluation of methods. In: TietzNW, ed. Textbook of Clinical Chemistry. Philadelphia: Saunders, 1986.
ElevitchFR, ed. Proc 1976 Aspen Conference on Analytical Goals in Clinical Chemistry. Skokie, IL:CAP, 1977.
11.
Proceedings of the Subcommittee on Analytical Goals in Clin Chem. World Association of Societies of Pathology, London, England. Analytical goals in clinical chemistry: their relationship to medical care. Am J Clin Pathol1979; 79: 624–30.
12.
FraserCG. The application of theoretical goals based on biological variation in proficiency testing. Arch Pathol Lab Med1988; 112: 404–15.
13.
RossJW. Evaluation of precision. In: WernerM. ed. Handbook of Clinical Chemistry. Vol. 1. Boca Raton, FL: CRC Press, 1982: 391–422.
14.
Fuentes-ArderiuXCases-ReganyEFrey-GonzálezEInterpretación de un cambio entre dos valores consecutivos de una magnitud bioquímica. Quím Clín1989; 8: 357–61.
15.
BarnettRN. Quality control in the clinical laboratory: an individual perspective. Lab Med1989; 20: 385–7.
16.
FraserCGPetersenPHLarsonML. Setting analytical goals for random analytical error in specific clinical monitoring situations. Clin Chem1990; 36: 1625–8.
17.
GlickMRRyderKWJacksonSA. Graphical comparisons of interferences in clinical chemistry instrumentation. Clin Chem1986; 32: 470–5.
18.
BroughtonPMG. Carry-over in automated analysers. J Auto Chem1984; 6: 94–5.