Variability between laboratories performing coagulation tests with identical platforms: a nationwide evaluation study
- PDF / 169,971 Bytes
- 6 Pages / 595.28 x 793.7 pts Page_size
- 119 Downloads / 142 Views
ORIGINAL CLINICAL INVESTIGATION
Open Access
Variability between laboratories performing coagulation tests with identical platforms: a nationwide evaluation study Michael Nagler1, Lucas M Bachmann2, Lorenzo Alberio3, Anne Angelillo-Scherrer4, Lars M Asmis5,12, Wolfgang Korte6, Adriana Mendez7, Guido Reber8, Hans Stricker9, Dimitrios A Tsakiris10 and Walter A Wuillemin1,11*
Abstract Background: While the assessment of analytical precision within medical laboratories has received much attention in scientific enquiry, the degree of as well as the sources causing variation between them remains incompletely understood. In this study, we quantified the variance components when performing coagulation tests with identical analytical platforms in different laboratories and computed intraclass correlations coefficients (ICC) for each coagulation test. Methods: Data from eight laboratories measuring fibrinogen twice in twenty healthy subjects with one out of 3 different platforms and single measurements of prothrombin time (PT), and coagulation factors II, V, VII, VIII, IX, X, XI and XIII were analysed. By platform, the variance components of (i) the subjects, (ii) the laboratory and the technician and (iii) the total variance were obtained for fibrinogen as well as (i) and (iii) for the remaining factors using ANOVA. Results: The variability for fibrinogen measurements within a laboratory ranged from 0.02 to 0.04, the variability between laboratories ranged from 0.006 to 0.097. The ICC for fibrinogen ranged from 0.37 to 0.66 and from 0.19 to 0.80 for PT between the platforms. For the remaining factors the ICC’s ranged from 0.04 (FII) to 0.93 (FVIII). Conclusions: Variance components that could be attributed to technicians or laboratory procedures were substantial, led to disappointingly low intraclass correlation coefficients for several factors and were pronounced for some of the platforms. Our findings call for sustained efforts to raise the level of standardization of structures and procedures involved in the quantification of coagulation factors. Keywords: Inter-rater variability, Intraclass correlation coefficient, Reproducibility of testing, Test validity
Introduction While the assessment of analytical precision within one medical laboratory has received much attention in scientific enquiry, extent and sources of variability that occur between laboratories quantifying the same parameter remains incompletely understood. In view of the fact that the clinical value of a laboratory test depends directly on its reproducibility and comparability [1], the scientific community has made great efforts to promote analytical * Correspondence: [email protected] 1 Division of Hematology and Central Hematology Laboratory, Luzerner Kantonsspital, Lucerne 16 CH-6000, Switzerland 11 University of Berne, Berne CH-3000, Switzerland Full list of author information is available at the end of the article
precision within laboratories lately [2-4]. For example, external quality assessment programs (EQA) were introduced to improve c
Data Loading...
