Correlation of quantitative examination of urinary sediment bacteria and urine culture / 国际检验医学杂志

ABSTRACT

Objective To evaluate quantitative examination of urinary sediment bacteria as a basic feasibility of screening indicators for urinary tract infection .Methods 191 outpatients and inpatient specimens were gathered firstly to implement a urine culture ,and then the rest of the urine were used for sediment bacteria quantitative testing .Meanwhile ,bacterial culture was conducted as the standard .According to the results of bacterial culture ,receiver operating characteristic(ROC) was drawn ,the threshold values of leukocyte and bacteria counts for diagnosis of urinary tract infection were found out and its sensitivity ,specificity ,positive / negative predictive value ,false positive/false negative rate and accuracy were calculated .Results The positive rate of urine culture was 39 .7% ,and the most common pathogen was Escherichia coli .The threshold value of bacteria and leukocyte counts for diagnosis of urinary tract infection was 1 024 .5/μL and 135 .8/μL respectively .When combined leukocyte and bacteria counts for urinary tract infection ,the optimum sensitivity was 62 .5% ,specificity was 98 .1% ,positive predictive value was 95 .7% ,negative predictive value was 79 .6% ,false positive rate was 1 .9% ,false negative rate was 37 .5% ,and accuracy was 83 .8% .Conclusion With UF‐1000i urinary sediment analyzer ,the combined determination of leukocyte and bacteria counts can remove the great mass of negative results ,Especially the results of bacterial culture positive predictability is higher ,but still can not replace of quantitative bacterial culture .