Urine sediment examination: a comparison of automated urinalysis systems and manual microscopy.
BACKGROUND
Several automated instruments examining urine sediment have been introduced. We compared the performance of Sysmex UF-100 and Iris iQ200 with manual microscopy in urine sediment testing.


METHODS
Four hundred and thirty-six urine samples were collected. The urine sediments were examined by manual microscopy and these 2 automated urinalysis systems.


RESULTS
The within-run CVs for urine samples ranged from 3.4% to 22.3% for the iQ200, 1.6% to 24.2% for the UF-100 and 12.5% to 43.9% for manual microscopy. Between-run CVs on quality-control samples ranged from 6.1% to 32.4% for the iQ200 and 3.5% to 24.7% for the UF-100. The agreement between methods was good for red blood cells and white blood cells counts based on r values of 0.935 to 0.968. However, for epithelial cells, the values measured by different systems were poorly correlated (r=0.888-0.922). The Bland-Altman plot indicated a trend towards the automated cell count being greater than the manual microscopy as the epithelial cell count increased. Casts were difficulty differentiated by 2 automated systems.


CONCLUSIONS
These 2 automated urinalysis systems demonstrated good concordance with each other in urine sediment examination. The automated process could be used as a screening procedure but some manual microscopy was still necessary.
Chien
Tzu-I
TI
Department of Laboratory Medicine, National Taiwan University Hospital, Taiwan.
Kao
Jau-Tsuen
JT
Liu
Hui-Lan
HL
Lin
Po-Chang
PC
Hong
Jhih-Sian
JS
Hsieh
Han-Peng
HP
Chien
Miao-Ju
MJ
D001322:Autoanalysis / Q000295:instrumentation; D006801:Humans; D008853:Microscopy; D016482:Urinalysis / Q000295:instrumentation*; D014556:Urine / Q000737:chemistry*