Sources of preanalytical errors and the role of training in error prevention

Objectives: We aimed to analyze the preanalytical errorsand the role of training in the prevention of error insamples sent to the biochemistry and microbiology laboratories.Materials and methods: All samples accepted in thecentral laboratory during eight-month period were evaluatedretrospectively. Distribution of rejected sampleswere classified according to preanalytical error categories(wrong sample, improper sample, incorrect barcode,insufficient volume, exceeded volume, clotted sample,hemolyzed/lipemic samples, contamination and otherreasons) and study groups. The type and the frequencyof errors in the laboratory study groups were shownas a percentage of total errors and the total number ofsamples. Contamination rates in blood and urine culturesand distribution of contamination rates in urine culturesaccording to gender and age were investigated. In addition,error rates before and after routine training aboutpreanalytical processes were compared.Results: The frequency of preanalytical error was 0.77 %.The first three most common errors were; contamination(30.4 %), clotted sample (19.4 %) and insufficient volume(15.6 %). Contamination rates were higher in urine cultures(88.2 %) than those in blood cultures (11.2 %) andthe most frequent error in urine cultures was observedin women and the patients under the age of 18. In addition,it was determined that the error rates significantlydecreased after the training (p<0.05).Conclusions: Laboratory and phlebotomy staff should beeducated continuously in order to reduce the error rate inthe preanalytical phase of the laboratory testing process.Key words: Preanalytical error, insufficient volume, clottedsample, contamination, training