CLINICAL QUALITY REQUIREMENTS

This table contains information on Clinical quality requirement that describe medically important changes in test values, or Decision Intervals (D_int) expressed as a percentage change at a certain Decision Level (D_int = change divided by decision level multiplied by 100 to give a percentage). The sources of the decision intervals presented here are the paper by Skendzel, Barnett, and Platt and a series of recommendations for lipid tests from the National Cholesterol Education Program (NCEP).

To make practical use of these clinical quality requirements, it is also necessary to have information about pre-analytical factors, particularly within-subject biological variation(s_wsub). The sources of estimates of within-subject biological variation presented here are summaries provided by Fraser and individual references from or cited by NCEP in their recommendations for lipid tests.

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Clinical Quality Requirements
Test	Decision Level	D_int(%)	Source	s_wsub(%)	Source
AST	30 IU.L 70 IU/L	43.3% 28.6%	Skendzel Skendzel	10.8%	Fraser
Bilirubin, total	0.8 mg/dL 15.0 mg/dL	75.0% 13.3%	Skendzel Skendzel	18.1%	Fraser
Calcium	8.5-9.0 mg/dL	10/6%	Skendzel	2.0%	Fraser
Cholesterol, total	210 mg/dL 200 mg/dL	33.3% 20.0%	Skendzel NCEP	6.1% 6.5%	Fraser Costongs
Cholesterol, HDL	60 mg/dL	42.0%	NCEP	7.5%	Warnick
Cholesterol, LDL	130 mg/dL	23.1%	NCEP	8.2%	Backorik
Creatinine	1.0 mg/dL 3.0 mg/dL	50% 16.7%	Skendzel Skendzel	4.9%	Fraser
Glucose	100 mg/dL	30.0%	Skendzel	12.2%	Fraser
Iron	150 ug/dL	33.3%	Skendzel	19.8%	Fraser
Potassium	3.8 mmol/L	10.5%	Skendzel	4.9%	Fraser
Sodium	125 mmol/L 135mmol/L	4.0% 4.4%	Skendzel Skendzel	0.8%	Fraser
Thyroxine, total	6.0 ug/L	33.3%	Skendzel	5.8%	Fraser
Total protein	7.0 g/dL	21.4%	Skendzel	3.3%	Fraser
Triglyceride	130 mg/dL	46.2% 100%	Skendzel NCEP	19.8% 23.7%	Fraser Stein
Urea nitrogen	18.0 mg/dL 40.0 mg/dL	56.6% 20.0	Skendzel Skendzel	12.2%	Fraser
Hematocrit	42 mg/dL	11.9%	Skendzel	2.5%	Fraser
Hemoglobin	15.0 g/dL	8.0%	Skendzel	2.4%	Fraser
Leukocyte count	5x10⁹ cell/L 25x10⁹ cell/L	32% 28%	Skendzel Skendzel	15.6%	Fraser
Prothrobin time	12.0 sec 20.0 sec	25.0% 25.0%	Skendzel Skendzel	2.3%	Dot

Sources

Backorik PS, Ross JW. National Cholesterol Education Program recommendations for measurement of low-density lipoprotein cholesterol: executive summary. Clin Chem 1995;41:1414-1420.
Costongs GMPJ, Janson PCW, Bas BM, et al. Short-term and long-term intra-individual variations and critical differences of clinical chemical laboratory parameters. J Clin Chem Clin Biochem 1985;23:7-16.
Dot D, Miro J, Fuentes-Arderiu X. Within-subject and between-subject biological variation of prothrombin time and activated partial thromboplastin time. Ann Clin Biochem 1992;29:422-425.
Fraser CG. Biological variation in clinical chemistry. An update: collated data, 1988-1991. Arch Pathol Lab Med 1992;116:916-923.
Fraser CG. The application of theoretical goals based on biological variation data in clinical chemistry. Arch Pathol Lab Med 1998;112:404-415.
Fraser CG. Desirable standards for hematology tests: a proposal. Am J Clin Pathol 1987;88:667-669.
National Cholesterol Education Program Laboratory Standardization Panel. Current status of blood cholesterol measurement in clinical laboratories in the United States. Clin Chem 1988;34:193-201.
Skendzel LP, Barnett RN, Platt R. Medically useful criteria for analytic performance of laboratory tests. Am J Clin Pathol 1985;83:200-205.
Stein EA, Myers GL, for the working group on lipoprotein measurement. National Cholesterol Education Program recommendations for triglyceride measurement: executive summary. Clin Chem 1995;41:1421-1426.
Warnick GR, Wood PD, for the NCEP working group on lipoprotein measurement. National Cholesterol Education Program recommendations for measurement of high-density lipoprotein cholesterol: executive summary. Clin Chem 1995;41:1427-1433.

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