Clinical Chemistry AACC Online Job Center
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 46: 89-99, 2000;
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (12)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jenny, R. W.
Right arrow Articles by Jackson-Tarentino, K. Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jenny, R. W.
Right arrow Articles by Jackson-Tarentino, K. Y.
Related Collections
Right arrow Laboratory Management
(Clinical Chemistry. 2000;46:89-99.)
© 2000 American Association for Clinical Chemistry, Inc.

Articles

Causes of Unsatisfactory Performance in Proficiency Testing

Richard W. Jennya and Kathryn Y. Jackson-Tarentino

a Author for correspondence. Fax 518-473-2900; e-mail jenny{at}wadsworth.org

Background: Proficiency testing (PT) provides a measure of the effectiveness of laboratory quality assurance programs. Test reports are released from processes that the laboratory judges to be in conformance with quality specifications; an evaluation of unsatisfactory performance (UNSAT) by a PT provider is an unexpected outcome for the laboratory. An understanding of the root cause(s) of testing errors provides an opportunity for the continuous improvement of laboratory services.

Methods: We used participant data from the New York State Department of Health PT program to characterize the quality of testing in the toxicology specialty. Outcomes from laboratory investigations into causes of UNSAT and information on quality control practices collected from all program participants were used to identify the root causes of error.

Results: Two classes of error were encountered: spurious test results caused by lapses in standard operating procedures and instrument malfunctions (300 per million assays) and common-cause analytic error (7000 per million assays or 0.7% rate of UNSAT). Causes of spurious results included inaccurate mathematical correction for specimen dilution, misinterpretation of instrument codes, and instrument sampling errors. Calibration drift was most frequently cited as the common-cause analytic error. Approximately one-half of the laboratories used an allowable error for the quality control of analytical systems that exceeded the threshold error specified by manufacturers for stable instrument performance.

Conclusions: The causes of spurious results suggest the need for ongoing competency testing of analysts where analyst intervention is required in an otherwise automated process, and for continued diligence in mistake-proofing instrument design. The intrinsic quality of laboratory testing is unlikely to improve until the allowable error in quality control is consistent with manufacturer specifications for stable system performance.




The following articles in journals at HighWire Press have cited this article:


Home page
 Clin. Chem.Home page
P. Bonini, M. Plebani, F. Ceriotti, and F. Rubboli
Errors in Laboratory Medicine
Clin. Chem., May 1, 2002; 48(5): 691 - 698.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2000 by the American Association for Clinical Chemistry.