Error identification in a high-volume clinical chemistry laboratory: Five-year experience.
BACKGROUND
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.


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.
Department of Pathology & Microbiology, Aga Khan University , Karachi , Pakistan.
Lena
L
Jafri
Aysha Habib
AH
Khan
Farooq
F
Ghani
Shahid
S
Shakeel
Ahmed
A
Raheem
Imran
I
Siddiqui
D002624:Chemistry, Clinical / Q000592:standards*; D019411:Clinical Laboratory Techniques / Q000592:standards*; D003951:Diagnostic Errors; D006801:Humans; D007753:Laboratories; D018962:Phlebotomy / Q000592:standards*; D011786:Quality Control
Laboratory proficiency testing; errors; healthcare; quality control; quality indicators