Introduction: In our country, very few of clinical
laboratories are running proper quality control program
and to the best of our knowledge the preanalytical,
analytical, and postanalytical rates of laboratory errors have
not been studied extensively. In this study we evaluated the
preanalytical, analytical, and postanalytical components of
laboratory errors in 3,200 consecutive specimens of a
clinical chemistry laboratory in a tertiary hospital for
measurement of different analyte concentrations in plasma
or serum. Materials and methods: This study was conducted
during the period from June 2009 to July 2010 on 3,200
specimens. Analytical errors were detected by repeat analysis
of primary sample and by checking quality control. Results:
The numbers of preanalytical, analytical and postanalytical
errors were 23, 14 and 76 respectively among 32000 tests
that we have done on 3,200 specimens (average 10 tests per
specimen). Moreover, the causes of errors were analyzed
and it was found that preanalytical errors were mostly due
to specimen drawn distal to IV infusion, specimen for
potassium first drawn into GREY tube (containing sodium
fluoride and K EDTA) and then transferred into GREEN
tube, long tourniquet time and underfilling of blood
collection tube. The analytical errors were due to random
and systemic errors and postanalytical errors were due to
transcription errors. Conclusion: Results of our study
suggest that errors mostly occur in the postanalytical part
of testing and they are due to transcription errors. To reduce
the laboratory errors we suggest introduction of Laboratory
Information System (LIS) of the clinical laboratories
connected with Hospital Management System along with
stringent quality control program in preanalytical, analytical
and postanalytical stages.
Key words: Preanalytical, Analytical, Postanalytical,
Transcription errors