ABSTRACT
Objective To investigate the value of red blood cell distribution width (RDW) in the diagnosis of Iron Deficiency Anemia(IDA).Methods Most relevant studies,which were retrieved from the Medline,Embase,and the Cochrane Library were identified according to the inclusion and exclusion criteria and data were extracted.Statistical analyses were performed by employing Meta-DiSc 1.4 software.Meta-analysis of the reported accuracy of each study was performed and summary receiver operating characteristic (SROC) curve was drawn.Results Four studies met the inclusion criteria for the analysis.Heterogeneity test did not find significant heterogeneity among included studies.RDW＞14％ was taken as the diagnostic critical value,the sensitivity was 0.92[95％CI(0.88,0.94)],the specificity was 0.41[95％CI(0.35,0.47)] and the AUC of SROC was 0.87.Conclusion RDW is sensitive and has good value in the diagnosis of IDA.
ABSTRACT
Objective To discover and certify the minimum required months of IQC ( Internal Quality Control ) data which were used to quantify the imprecision To identify the impact of test items , different concentrantions and years on the defective rate .Methods IQC data involving 20 analysis items ( including Albumin, Creatine kinase, Total bilirubin, Alanine aminotransferase, Aspartate aminotransferase, Lactate dehydrogenase,γ-Glutamyl transferase, Alkaline phosphatase, Calcium, Chlorine, Creatinine, Glucose, Potassium, Sodium, Phosphorus, Triglyceride, Total cholesterol, Total protein, Uric acid, Urea) and six measurement systems (including Roche, Architect, Hitachi, Dade/Behring, Beckman, Olympus) were collected from hospitals in Shanghaibetween 2009 and 2011.A total of 3 534 groups, referred to one year laboratory′s IQC data of one concentration range , were analysed to find the minimum required months in each group when the cumulative months were compared with the population by using T test.The correlation coefficient of hospital′grades, measurement levels and test items were evaluated by u test, and the percentage of groups of P>0.05 were collected.The cumulative IQC data′coefficient variation ( CV) of six months and eleven months were compared with the total CV, respectively .Imprecision higher than the professional specification was regarded as unqualified .Difference of unqualified rate among test items, concentrations and years were expolored .Results Rates of hospital′grades, measurement levels , items are 94.2%,100%, 100%respectively , 88%of groups′imprecision became stable in ten months .25%groups reach the criteria that the relative bias is ≤5% when calculated the cumulative IQC data′CV of six months, while 88%groups do when calculated the cumulative IQC data′CV of ten months.The unqualified rate is 20%and the most unqualified item is Ca , the unqualified groups of low level are larger .With increase of year , the unqualified rate showed a downtrend .Conclusions Ten months′IQC data is more reliable to quantify imprecision .Unqualified rates are different according to test items , measure levels and years , the establishment of professional specification should consider them.
ABSTRACT
Objective To establish the methodology of uncertainty evaluation with reference measurement procedure by Monte Carlo method (MCM).Methods According to JCGM 101:2008,we established the methodology of uncertainty evaluation by MCM in the example of GGT reference measurement procedure.We could calculate an estimate of GGT concentration,the associated standard uncertainty and a coverage interval with a specified probability by MATLAB software,setting the uncertainty evaluation by GUM method as a control.Results When the uncertainty was evaluated by GUM method,the results of sample A and Sample B were (95.8 ±2.4) U/L (k =2) with coverage interval [93.4 U/L,98.2 U/L] and (180.0 ± 3.9) U/L (k =2) with coverage interval [176.1 U/L,183.9 U/L] respectively,while using MCM method,the uncertainty evaluation result of sample A and Sample B were (95.8 ± 2.4) U/L (k =2) with coverage interval [93.4 U/L,98.2 U/L] and (180.0 ± 3.9) U/L with symmetrical 95％ coverage interval [176.2 U/L,183.8 U/L].The output quantity simulated by MCM was normal distributed.Conclusions When the distribution of the output quantity is normal,the measurement uncertainty evaluated by both MCM and GUM method is nearly the same.When the distribution of the output quantity is unknown,MCM can be used as a verification of GUM method.