Guidelines for Clinical Chemistry Quality Control Based on the Long-term Experience of Sixty-one University and Tertiary Care Referral Hospitals: A Reappraisal

Autor: Bradley E. Copeland, Jon V. Straumfjord, Sanford R. Kurtz
Rok vydání: 1977
Předmět:
Zdroj: American Journal of Clinical Pathology. 68:463-473
ISSN: 1943-7722
0002-9173
DOI: 10.1093/ajcp/68.4.463
Popis: The day-to-day precision of tests of chemical constituents from 61 reference or referral level hospitals is summarized, based on the standard deviation and relative standard deviation. Data were characterized according to method, instrumentation, and pool concentration. Guidelines for individuals to use for evaluating within-laboratory performance of university hospitals over a 6- to 18-month period are suggested. It is emphasized that the desired precision for each test depends upon medical, scientific, and economic factors. The most important controlling factor is the medical use to which the measurement will be put. Differences in methods were evaluated using F test ratios. Methodology accounted for few differences in precision. A comparison made between “the state of the art” performance ranges compiled in 1965 and 1975 showed improvement. The onestandard- deviation value for constituents was most often directly related to serum pool concentration. Relative standard deviation (coefficient of variation) of enzymes, however, was most often inversely related to pool level. Using Barnett’s medical usefulness criteria,2 all laboratories (100%) achieved the levels of precision specified for glucose, urea nitrogen, sodium, potassium, creatinine, cholesterol, and bilirubin; 33 of 38 laboratories (88%) exceeded the medically useful limit for calcium; 53 of 58 laboratories (91%) exceeded the limit for triglycerides. A series of goals for the present and the future that include both theoretical and practical considerations are presented.
Databáze: OpenAIRE