Tools, Technologies and Training for Healthcare Laboratories

Clinical Quality Requirements

This table contains information on Clinical quality requirement that describe medically important changes in test values, or Decision Intervals (Dint) expressed as a percentage change at a certain Decision Level (Dint = 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(swsub). 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.


Clinical Quality Requirements
Test Decision Level Dint(%) Source swsub(%) 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.