The results of external quality assessment programme on urine leukocyte and erythrocyte counting in Poland.

Agnieszka Ćwiklińska,Aleksandra Fijałkowska,Gabriela Bednarczuk,Robert Kowalski,Maciej Jankowski,Barbara Kortas-Stempak,Agnieszka Kuchta

doi:10.11613/bm.2020.020707

Agnieszka Ćwiklińska, Aleksandra Fijałkowska + Show 5 more

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https://doi.org/10.11613/bm.2020.020707

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Journal: Biochemia Medica	Publication Date: Jun 14, 2020
Citations: 3	License type: cc-by

Affiliation: Gdańsk Medical University, Meditest

Abstract

IntroductionUrine particle analysis is an important diagnostic tool. The aim of this study was to evaluate the quality of urine leukocyte (WBC) and erythrocyte (RBC) counting results obtained with manual and automated methods in Polish laboratories participating in the international external quality assessment (EQA) programme.Materials and methods1400 WBC and RBC counting results were obtained from 183 laboratories in EQA surveys organised by Labquality (Helsinki, Finland) from 2017 to 2019. The between-laboratory coefficient of variation (CV), the percentage difference between the laboratories' results and target values (Q-score (%)), as well as modified Youden plots were analysed.ResultsFor automated method groups, the medians of inter-laboratory CVs varied from 14% to 33% for WBC counting and from 10% to 39% for RBC counting. For manual method groups, the medians of CV varied from 53% to 71% (WBC) and from 55% to 70% (RBC), and they were significantly higher, in comparison to CVs for most automated method groups (P < 0.001). The highest percentage of results outside the target limits (36%) and the highest range of Q-score (%) (from - 93% to 706%) were observed for laboratories which participated in the surveys for the first or second time. The percentage of deviating results and the ranges of Q-score decreased with an increased frequency of laboratories’ participation in the surveys.ConclusionsThe quality of manual methods of urine WBC and RBC counting is unsatisfactory. There is an urgent need to take actions to improve laboratories’ performance and to increase harmonisation of the results.

Highlights

Urine particle analysis is an important diagnostic tool
For automated method groups, the medians of inter-laboratory coefficient of variation (CV) varied from 14% to 33% for WBC counting and from 10% to 39% for RBC counting
For WBC counting, the medians of CV for manual methods varied from 53% (47-72%; 25th75th percentiles) for the direct chamber counting method to 71% (49-81%) for the coverslip method, and were significantly higher in comparison to medians of CV for most automated method groups, which varied from 14% (8%-18%) for Analyser A to 33% (27%-56%) for Analyser C (Figure 1)

Summary

Introduction

Urine particle analysis is an important diagnostic tool. Urine particle analysis is an important diagnostic tool for renal and urinary tract diseases [1]. Manual microscopic and automated methods are used for urine particle analysis. Automated analysers have better accuracy and precision than manual methods [5] Their application enables the reduction of time, labour and cost of analysis [6]. They have limitations in the recognition of urine elements, especially in highly pathologic samples [7,8]. Microscopic methods are still considered as the ‘gold standard’ [1,2]

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