Guidelines for setting up an External Quality Assessment Scheme for blood smear interpretation. Part II: survey preparation, statistical evaluation and reporting

AbstractBlood smear analysis is a well-known technique in medical laboratories. The clinical relevance of this analysis and its interpretation are very important. Consequently, monitoring of laboratory performance by an external quality assessment scheme is strongly recommended. This article represents a very practical guidance document for External Quality Assessment Scheme (EQAS) organizers for setting up blood smear schemes. In the first part of the guidelines, the Hematology Working Group of the European External Committee for External Quality Assurance Programmes in Laboratory Medicine (EQALM) published practical information for the preparation of blood smears for use in an EQAS. Part II focuses on aspects such as survey preparation, statistical evaluation and reporting, and describes particular details for organizing blood morphology EQA surveys by means of virtual microscopy.Clin Chem Lab Med 2006;44:1039–43.

Author(s):  
Juan-Lluis Vives Corrons ◽  
Stephanie Albarède ◽  
George Flandrin ◽  
Silke Heller ◽  
Katalin Horvath ◽  
...  

AbstractBlood smear analysis is a well known technique in medical laboratories. Clinical relevance of this analysis and its interpretation are very important. Consequently, monitoring of laboratory performance by an external quality assessment scheme is strongly recommended. Most starting external quality organizers set up a scheme for clinical chemistry. Due to a lack of guidance documents, many organizers are reluctant to offer a hematology scheme. This article aims to be a very practical guidance document for external quality assessment organizers for the set up of blood smear schemes.


2017 ◽  
Vol 100 (5) ◽  
pp. 1277-1287 ◽  
Author(s):  
Carolyn Q Burdette ◽  
Johanna E Camara ◽  
Federica Nalin ◽  
Jeanita Pritchett ◽  
Lane C Sander ◽  
...  

Abstract Until recently, the Vitamin D External Quality Assessment Scheme (DEQAS) assessed the performance of various assays for the determination of serum total 25-hydroxyvitamin D [25(OH)D] by using a consensus mean based on the all-laboratory trimmed mean (ALTM) of the approximately 1000 participants' results. Since October 2012, the National Institute of Standardsand Technology (NIST), as part of the Vitamin D Standardization Program, has participated in DEQAS by analyzing the quarterly serum sample sets using an isotope dilution LC-tandem MS (ID LC-MS/MS) reference measurement procedure to assign an accuracy-based target value for serum total 25(OH)D. NIST has analyzed90 DEQAS samples (18 exercises × 5 samples/exercise) to assign target values. The NIST-assigned values are compared with the ALTM and the biases assessed for various assays used by the participants, e.g., LC-MS/MS, HPLC, and several ligand-binding assays. The NIST-value assignment process and the resultsof the analyses of the 90 DEQAS samples are summarized. The absolute mean bias between the NIST-assignedvalues and the ALTM was 5.6%, with 10% of the samples having biases >10%. Benefits of the accuracy-based target values are presented, including for sample sets with high concentrations of 25(OH)D2 and 3-epi-25(OH)D3.


Author(s):  
Chao-Yang Chen ◽  
Meng-Ya Li ◽  
Ling-Yun Ma ◽  
Xing-Yu Zhai ◽  
Dao-Huang Luo ◽  
...  

Abstract Background Vancomycin remains a mainstay of the treatment of Gram-positive bacterial infections. It is crucial to accurately determine vancomycin serum concentration for adequate dose adjustment. Objectives To evaluate the precision and accuracy of commercial assay techniques for vancomycin concentration and to assess the comparability of vancomycin detection methods in Chinese laboratories. Methods Human serum samples spiked with known concentrations of vancomycin were provided to laboratories participating in the external quality assessment scheme (EQAS). Assay methods included chemiluminescence, enzyme immunoassay (EIA) and so on. The dispersion of the measurements was analysed and the robust coefficient of variation (rCV), relative percentage difference (RPD) and satisfactory rate for method groups were calculated. Moreover, performance of the Chinese laboratories was assessed. Results A total of 657 results from 75 laboratories were collected, including 84 samples from 10 Chinese laboratories. The median rCV, median RPD and satisfactory rates classified by methods ranged from 1.85% to 15.87%, −14.75% to 13.34% and 94.59% to 100.00%, respectively. Significant differences were seen in precision, between kinetic interaction of microparticles in solution (KIMS) and other methods, and in accuracy, between enzyme-multiplied immunoassay technique (EMIT), fluorescence polarization immunoassay (FPIA) and other techniques. Vancomycin detection in China mainly depended on the chemiluminescence and EMIT methods, which tended to result in lower measurements. Conclusions Although almost all assays in this study achieved an acceptable performance for vancomycin serum concentration monitoring, obvious inconsistencies between methods were still observed. Chinese laboratories were more likely to underestimate vancomycin concentrations. Thus, recognizing inconsistencies between methods and regular participation in vancomycin EQAS are essential.


2008 ◽  
Vol 182 (1-3) ◽  
pp. 35-40 ◽  
Author(s):  
M. Ventura ◽  
R. Ventura ◽  
S. Pichini ◽  
S. Leal ◽  
P. Zuccaro ◽  
...  

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