Abstract：
BACKGROUND:It is important that cardiac troponin be measured accurately with a robust method to limit false results with potentially adverse clinical outcomes. In this study, we characterized the robustness of 4 analytical platforms by measuring the outlier rate between duplicate results. METHODS:We measured cardiac troponin concurrently in duplicate with 4 analyzers on 2391 samples. The outliers were detected from the difference between duplicate results and by calculating a z value: z = (result 1 - result 2) ÷ √(SD1(est)² + SD2(est)²), with z > 3.48 identifying outliers with a probability of 0.0005. RESULTS:The outlier rates were as follows: Abbott Architect i2000SR STAT Troponin-I, 0.10% (0.01%-0.19%); Beckman Coulter Access2 Enhanced AccuTnI, 0.44% (0.25%-0.63%); Roche Cobas e601 TroponinT hs, 0.06% (0.00%-0.13%); and Siemens ADVIA Centaur XP TnI-Ultra, 0.10% (0.01%-0.19%). The occurrence of outliers was higher than statistically expected on all platforms except the Cobas e601 (χ² = 2.7; P = 0.10). A conservative approach with a constant 10% CV and z > 5.0 identified outliers with clear clinical impact and resulted in outlier rates of 0.11% (0.02%-0.20%) with the Architect i2000SR STAT Troponin-I, 0.36% (0.19%-0.53%) with the Access2 Enhanced AccuTnI, 0.02% (0.00%-0.06%) with the Cobas e601 TroponinT hs, and 0.06% (0.00%-0.13%) with the ADVIA Centaur XP TnI-Ultra. CONCLUSIONS:Outliers occurred on all analytical platforms, at different rates. Clinicians should be made aware by their laboratory colleagues of the existence of outliers and the rate at which they occur.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Pretorius CJ,Dimeski G,O'Rourke PK,Marquart L,Tyack SA,Wilgen U,Ungerer JPdoi
10.1373/clinchem.2010.159830subject
Has Abstractpub_date
2011-05-01 00:00:00pages
710-8issue
5eissn
0009-9147issn
1530-8561pii
clinchem.2010.159830journal_volume
57pub_type
杂志文章abstract：BACKGROUND:It has been shown that a high percentage of interleukin-8 (IL-8) in blood is cell associated. Recently, a simple method for determination of cell-associated IL-8 in whole blood after cell lysis has been described. The purpose of this study was to evaluate this method, to examine the influence of preanalytic ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2000-09-01 00:00:00
abstract：BACKGROUND:Suspension array technology has surpassed ELISA for automated, simultaneous detection and quantification of soluble biomarkers such as virus-specific antibodies. We describe assays in which antigens are attached to a lipid bilayer surrounding color-coded particles. METHODS:We used layer-by-layer technology ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.065789
更新日期：2006-08-01 00:00:00
abstract：:We describe a radioassay for cobalamin (vitamin B12) in human serum or plasma that requires no boiling or other pretreatment of the sample. Normal chicken serum covalently coupled to magnetizable particles is used as the binding agent. The assay is performed at pH 12.9, at which pH all cobalamin in human serum is rele...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-02-01 00:00:00
abstract：BACKGROUND:Human iron status is influenced by environmental and genetic factors. We hypothesized that the genetic polymorphism of haptoglobin (Hp), a hemoglobin-binding plasma protein, could affect iron status. METHODS:Reference values of serum iron status markers were compared according to Hp phenotypes (Hp 1-1, Hp 2...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2000-10-01 00:00:00
abstract：:We conducted a proficiency survey of cholesterol and high-density lipoprotein (HDL) cholesterol analysis in local clinical laboratories to determine whether increased national emphasis on cholesterol measurement had resulted in changes in performance from previous surveys. Sets of frozen aliquots of plasma and HDL sup...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-08-01 00:00:00
abstract：:We describe a high-performance liquid chromatographic method for the quantitative determination of gentamicin in serum. The antibiotic was separated from serum by passage through a silicic acid column, derivatized with o-phthalaldehyde, and eluted with ethanol. The derivatized gentamicin was then separated into all th...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-12-01 00:00:00
abstract：:We compared cotinine, carboxyhemoglobin, and thiocyanate concentrations in blood sampled from 187 cigarette smokers and 181 non-smokers. All three differed significantly between smokers and non-smokers. Cotinine performed best as a test for assessing smoking status, with a sensitivity of 98% as compared with 94% for c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-08-01 00:00:00
abstract：:An optimized assay for alkaline phosphatase (EC 3.1.3.1) is reported. A discrete analyzer, the DuPont Automatic Clinical Analyzer (aca), was used for this study. The assay is based on results of response-surface experimental co-optimization techniques, and response is enhanced over the present aca assay. A key feature...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-07-01 00:00:00
abstract：:This communication describes and evaluates an improved routine methodology for quantitating clinical proteinuria. Based on investigations of Piscator and of Savory et al., a modified Tsuchiya's reagent (ethanolic HCI-phosphotungstic acid) is used to precipitate proteins at 56 degrees C, followed by biuret spectrophoto...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-03-01 00:00:00
abstract：:Histograms of the results of quantitative clinical laboratory analyses are usually broadly skewed because some of the patients have normal values with respect to the analyte being measured while values for others are below or above normal. We describe a technique for calculating the maximum possible number of individu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-04-01 00:00:00
abstract：:We compared the ionic activity of sodium, as measured with glass electrodes, with sodium concentration in 23 healthy persons, 15 persons with acute renal failure, and before and after dialysis in 46 patients with chronic renal failure. In healthy persons the mean (+/- SEM) sodium concentration was 139.1 +/- 0.6 mmol/L...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-11-01 00:00:00
abstract：BACKGROUND:Laboratory tests can be an important source of blood loss in hospitals, especially for newborns and patients in intensive care. The aim of this study was to quantify blood loss for laboratory diagnostic tests in a large number of patients in a teaching hospital. METHODS:We estimated blood loss by multiplyin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.10.1651
更新日期：2003-10-01 00:00:00
abstract：:Estrogen receptor (ER) and progestin receptor (PR) concentrations in tumor biopsies are important predictive indicators of a clinical response to endocrine therapy of breast cancer. To assess interference of O.C.T. (optimum cutting temperature) embedding compound in assays of ER and PR by radioligand binding, we deter...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-12-01 00:00:00
abstract：BACKGROUND:Reduced renal function is an established risk factor for cardiovascular events. We compared 3 measures of renal function--serum cystatin C, serum creatinine, and calculated creatinine clearance--as predictors of subsequent cardiovascular events in a community-based population of elderly individuals. METHODS...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.135962
更新日期：2010-05-01 00:00:00
abstract：BACKGROUND:First introduced into clinical microbiology laboratories in Europe, MALDI-TOF MS is being rapidly embraced by laboratories around the globe. Although it has multiple applications, its widespread adoption in clinical microbiology relates to its use as an inexpensive, easy, fast, and accurate method for identi...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2014.221770
更新日期：2015-01-01 00:00:00
abstract：:This assay was developed to measure apolipoprotein (apo) B in blood samples spotted onto filter paper. The long-term aim is to detect young families with the dominantly inherited familial hypercholesterolemia, during current neonatal screening programs. The interassay CV was 5.6%, and apo B concentrations correlated c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-06-01 00:00:00
abstract：:We measured the concentration of erythrocyte protoporphyrin in 43 blood samples by two fluorometric methods. In the indirect method, protoporphyrin was extracted from blood and the fluorescence of the free acid in the extract was determined with a filter-fluorometer. These results were compared with results of direct ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-09-01 00:00:00
abstract：:The metabolism of the synthetic substrate 7-ethoxyresorufin is a selective measure of the activity of cytochrome P-448 monooxygenase, the subset of cytochrome P-450-mediated enzymes preferentially induced by polycyclic aromatic hydrocarbons and related compounds. 7-Ethoxycoumarin metabolism, on the other hand, reflect...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-09-01 00:00:00
abstract：:We evaluated the density-gradient ultracentrifugation method in a swinging-bucket rotor (Anal Biochem 111, 149-157, 1981) in a slightly modified version for isolation and determination of high-density lipoprotein (HDL) subfractions. We prestained the serum with Coomassie Brilliant Blue R, which did not change the hydr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-04-01 00:00:00
abstract：:Antithrombin III (AT III) activity was determined with two different new chromogenic substances--Chromozym-TH (Tos-Gly-Arg-p-nitroanilide; Boehringer Mannheim) and alpha-N-carbobenzyl-oxy-L-lysine-thiobenzyl ester (Du Pont)--with both a discrete (aca) and a centrifugal analyzer (COBAS BIO). The correlation between the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-11-01 00:00:00
abstract：:A gas-chromatographic method for urinary organic acid analysis is described, designed to be used routinely for the diagnosis of organic aciduria. It involves extraction of urine with ethyl acetate, dehydration of extract residues, and trimethylsilylation. Organic acids are identified by using an extensive list of rete...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-12-01 00:00:00
abstract：:Direct-injection analysis for phenylalanine in plasma by isocratic "high-performance" liquid chromatography (HPLC) is described. For chromatographic separation I use an internal-surface reversed-phase silica support. The method involves ultraviolet detection, requires as little as 10 microL of plasma (routinely 20 mic...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-06-01 00:00:00
abstract：:Since 1991, the Ontario Laboratory Proficiency Testing Program has assessed the analytical performance of creatine kinase (CK; EC 2.7.3.2) isoenzyme-2, using fresh human serum supplemented with purified human CK isoenzymes. In Ontario, the 142 laboratories licensed to analyze CK-2 use a variety of methods: electrophor...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-02-01 00:00:00
abstract：BACKGROUND:Mutations in the retina-specific ABC transporter (ABCA4) gene have been associated with several forms of macular degenerations. Because the high complexity of the molecular genotype makes scanning of the ABCA4 gene cumbersome, we describe here the first use of denaturing HPLC (DHPLC) to screen for ABCA4 muta...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.033241
更新日期：2004-08-01 00:00:00
abstract：:HbCO in blood sampled from 20 mothers and newborns immediately after birth was measured with a new, simple gas-chromatographic method for CO. The mean ratio of HbCO to total hemoglobin for 13 non-smoking mothers did not differ significantly from that for their infants (mean 0.38%, SD 0.26% vs 0.38%, SD 0.13%), but the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-01-01 00:00:00
abstract：:We describe a rapid, precise, and sensitive radiometric assay for human lactoferrin. In this typical "sandwich"-type assay, anti-human lactoferrin is adsorbed onto a polystyrene sphere and bound lactoferrin is detected by the subsequent binding of 125I-labeled anti-human lactoferrin. The assay is accurate for lactofer...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-03-01 00:00:00
abstract：:Creatine kinase (CK) isoenzymes MM, MB, and BB are located primarily in the cell cytosol, and increased CKMB in plasma is the hallmark of myocardial infarction. However, whether CK is released with reversible ischemic injury remains controversial. Here, we assessed plasma CK activity--cytosolic and mitochondrial CK--i...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-03-01 00:00:00
abstract：BACKGROUND:Recent recognition of its broad pathophysiological importance has triggered an increased interest in 25-hydroxyvitamin D [25(OH)D]. By consequence, throughput in 25(OH)D testing has become an issue for clinical laboratories, and several automated assays for measurement of 25(OH)D are now available. The aim o...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2011.176545
更新日期：2012-03-01 00:00:00
abstract：:A "high-performance" liquid-chromatographic procedure for 5-hydroxy-3-indoleacetic acid is described and compared with a colorimetric method in which 1-nitroso-2-naphthol is used. The analyte and an internal standard, p-nitrobenzoic acid, were extracted into diethyl ether from urine at pH 4.0 (acidified with HCl) to w...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-06-01 00:00:00
abstract：:We investigated the ability of neural networks to diagnose acute myocardial infarction (AMI) from laboratory data only. Several networks were trained with different combinations of data obtained at admission and within the first 12 h and 24 h after admission. The data used included the electrocardiogram (ECG) and the ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-04-01 00:00:00
