Study of preliminary screening value of urinary sediment method and urine dry chemical method in diagnosing urinary tract infection / 国际检验医学杂志

ABSTRACT

Objective To evaluate the preliminary screening value of bacterium(BACT),leukocyte count(WBC)detected by the UF-1000i urine sediment analyzer and nitrite(NIT)and leukocyte esterase(LEU)detected by the urine dry chemical dipstick analy-zer in diagnosing urinary tract infection(UTI).Methods A total of 346 inpatients or outpatients with suspected UTI in our hospital from July 2012 to June 2013 were performed the midstream urine culture.Among them,91 positive cases as the experimental group and 255 negative cases as the control group were simultaneously performed the urine dry chemical analysis and the urinary sediment analysis.The performance of the various indexes in screening UTI was evaluated with the bacterial culture results as the golden standard.Results The positive rates of NIT,LEU,WBC,BACT,NIT+LEU and WBC+BACT in the experimental group were significantly higher than those in the control group with the statistical differences between the two groups(P <0.05).The areas un-der the ROC curve for diagnosing UTI in NIT,LEU,WBC,BACT,NIT+LEU and WBC+BACT were 0.602,0.664,0.715, 0.770,0.713 and 0.760 respectively,95%CI was 0.530-0.675,0.603-0.725,0.655 -0.775,0.716 -0.824,0.651 -0.774 and 0.704-0.817 respectively;their sensitivity for diagnosing UTI was 0.26,0.86,0.79,0.74,0.86 and 0.85 respectively;The speci-ficity was 0.94,0.47,0.47,0.51,0.46 and 0.33 respectively;The positive likelihood ratio was 4.48,1.62,1.51,1.49,1.58 and 1.27 respectively;The negative likelihood ratio was 0.78,0.30,0.44,0.52,0.31 and 0.46 respectively;The positive predictive value was 0.62, 0.37,0.35,0.35,0.36 and 0.31 respectively;The negative predictive value was 0.78,0.90,0.86,0.84,0.90 and 0.86 respectively.Conclu-sion In the rapid screening of UTI,the indexes of NIT,LEU,WBC and BACT all have the higher negative predictive values.