Establishment and evaluation of the review criteria of automatic urine analysis workstations / 中华检验医学杂志

ABSTRACT

ObjectiveTo establish the proper review rules for the microscopic screening of urine samples tested by automatic urinalysis work station which is composed of LabUMat urine dry chemical analyzer and Urised urine sedimental analyzer.Methods The paired comparison was used to analyze the results tested by microscopy and Urised.A total of 2015 random urine samples were enrolled to establish and validate review rules.All the samples were collected from the inpatients and ontpatients of General Hospital of the People's Liberation Army from May to November 2011 and tested by urinalysis work station.2015 urine samples were firstly tested by urinalysis work station,including both urine dry chemical analyzer and urine sediments analyzer.Then each urine sample was examined microscopically by two technicians-in-charge using double-blind method.The average results from the two technicians were used as review results.Compared with review results,we set up the review rules and evaluated the Irue positive rate,false positive rate,true negative rate,false negative rate (omission diagnostic rate) and review rate.According to different test methods by automatic urinalysis work station,four microscopic review protocols were defined( 1 ) Protocol 1based on chemistry results only,microscopy review was performed when any of WBC,RBC,PRO and NIT was positive; (2) Protocol 2based on urine sedimental analysis only,microscopy review was performed when any of WBC,RBC and CAST count was over upper limit of the reference range ; (3) Protocol 3if any of BLD vs.RBC,LEU vs.WBC was different between two systems,or quantitative results had two or more than two gradient differences,microscopy review was performed; (4) Protocol 4if any of BLD vs.RBC,LEU vs.WBC was different between two systems,or CAST was over upper limit of the reference range,or alam appeared,microscopic review was performed.300 randomly selected urine samples were tested to validate the review rules.Omission diagnostic rate and review rate were used to evaluate the rules.Results According to our review rules,the positive samples rate was 41.14％ (829/2015) and the negative rate was 58.86％ ( 1186/2015 ) ; Positive samples were composed of RBC (50.30％),WBC (53.32％) and CAST (3.74％).The review rates of four protocols were 42.93％ (865/2015),39.70％ (810/2015),29.58％(596/2015),18.91％ (381/2015 ),respectively.The false negative rates (omission diagnostic rates) were 6.36％ (128/2015),4.42％ (89/2015),1.34％ (27/2015)and 1.04％ (21/2015)respectively.Protocol 4 was selected as an ideal plan.Additional 300 urine samples were tested using protocol 4 in order to confirm the review rule.The review rate,consistency rate,true positive rate,false positive rate,true negative rate,omission diagnostic rate were 19.67％ (59/300),91.67％ (275/300),35.67％ (107/300),7.67％(23/300),56.00％ (168/300),0.67％ (2/300),respectively.After image review revised,the review rate was 8.67％ (26/300).ConclusionThe review rules established by our research for Urinalysis Work Station can find the abnormal urine samples effectively and exactly and can reduce the workload significantly.(Chin J Lab Med,2012,35810-814)