Analysis of false positive results of Sysmex UF-1000i urine sediment analyzer

Objective To evaluate positive results of UF-1000i Urinary sediment analyzer and analyze false positive results.Methods A total of 500 urine samples were collected randomly and determined by UF-1000i full automatic urinary sediment analyzer(UF-1000i),urine strips and microscopic analysis.positive results of samples were deemed as false when results were abnormal with UF-1000i analyzing but normal with urine strips and microscopic analysis.Two results of urine formed elements were contrasted between UF-1000i and microscopic analysis in samples with false positive results.Results Totally 178 of 500 samples showed positive results with UF-1000i analysis,in which 20 samples were determined as false positive results in main examined items with microscopic analysis.In 178 positive results,the false positive rate of erythrocyte(RBC),leukocyte(WBC),cast and epithelial cells(EC) were 10.8%,8.2%,23.1% and 14.3% separately.Conclusion The analyses on urinary sediments by UF-1000i full automatic urinary sediment analyzer was effective.But it is important to observe sediments by microscope to avoid false positive results when results were abnormal with UF-1000i analysis.