Correspondence: Imran Siddiqui, Department of Pathology & Microbiology, Aga Khan University, Karachi, Pakistan. E-mail: imran.siddiqui@aku.edu
(Received 4 July 2014; accepted 18 January 2015)
ORIGINAL ARTICLE
Error identification in a high-volume clinical chemistry laboratory:
Five-year experience
LENA JAFRI, AYSHA HABIB KHAN, FAROOQ GHANI, SHAHID SHAKEEL,
AHMED RAHEEM & IMRAN SIDDIQUI
Department of Pathology & Microbiology, Aga Khan University, Karachi, Pakistan
Abstract
Introduction. Quality indicators for assessing the performance of a laboratory require a systematic and continuous
approach in collecting and analyzing data. The aim of this study was to determine the frequency of errors utilizing the
quality indicators in a clinical chemistry laboratory and to convert errors to the Sigma scale. Materials and methods.
Five-year quality indicator data of a clinical chemistry laboratory was evaluated to describe the frequency of errors. An
‘error’ was defined as a defect during the entire testing process from the time requisition was raised and phlebotomy was
done until the result dispatch. An indicator with a Sigma value of 4 was considered good but a process for which the Sigma
value was 5 (i.e. 99.977% error-free) was considered well controlled. Results. In the five-year period, a total of 6,792,020
specimens were received in the laboratory. Among a total of 17,631,834 analyses, 15.5% were from within hospital. Total
error rate was 0.45% and of all the quality indicators used in this study the average Sigma level was 5.2. Three indicators
– visible hemolysis, failure of proficiency testing and delay in stat tests – were below 5 on the Sigma scale and highlight
the need to rigorously monitor these processes. Conclusions. Using Six Sigma metrics quality in a clinical laboratory can
be monitored more effectively and it can set benchmarks for improving efficiency.
Key Words: Laboratory proficiency testing, quality control, quality indicators, healthcare, errors
Abbreviations: CAP, College of American Pathologists; AKUH, Aga Khan University Hospital; JCIA, Joint Commission
International Accreditation; SPSS, Statistical Package of Social Sciences; EQAS, External Quality Assurance Surveys.
Introduction
Quality assurance is the complete program that war-
rants that the final results reported by a laboratory are
correct. The objective of quality assurance is that the
right result is provided on the right specimen at the
right time and interpreted according to the right refer-
ence data [1,2]. The scientific monitoring of an ongo-
ing analytical performance and taking appropriate in
time measures to ensure quality results are a part of
daily practice in most clinical laboratories but test
result reliability cannot be achieved through the con-
trol of accuracy in the analytical part of testing process
alone. Precision and result accuracy are achieved
by both analytical and preanalytical monitoring of
processes [3].
To reduce preanalytical errors, clinical laborato-
ries emphasize on proper test entry with standardized
phlebotomy technique and proper transport and sample
storage to be followed [4]. The protocols to reduce
post analytical errors include proper entry of results,
results to be forwarded to pathologist for verification
or rectification, immediate delivery of results and
immediate communication of panic results.
An important point in improving laboratory
quality is the definition of some indicators to be
monitored as measures of a laboratory trend [5].
The College of American Pathologist (CAP) defines
‘quality improvement’ as the practice of continuously
assessing and adjusting performance using statisti-
cally and scientifically accepted procedures [6]. The
constant scrutiny of quality indicators and conse-
quent corrective actions can help to reduce errors
and the risk of errors, thus enhancing the laboratory
outcome [7]. In addition, the standardization of risk
evaluation techniques and the definition of a set of
indicators can eventually contribute to a benchmarking
Scandinavian Journal of Clinical & Laboratory Investigation, 2015; Early Online: 1–5
ISSN 0036-5513 print/ISSN 1502-7686 online © 2015 Informa Healthcare
DOI: 10.3109/00365513.2015.1010175
Scand J Clin Lab Invest Downloaded from informahealthcare.com by UBO Bib for Hum og Samfunnsviten on 04/20/15
For personal use only.