Proposals for Setting Generally Applicable Quality Goals Solely Based on Biology

Fraser, Callum G.; Petersen, Per Hyltoft; Libeer, Jean-Claude; Ricós, Carmen

doi:10.1177/000456329703400103

Cited by 319 publications

(221 citation statements)

References 15 publications

Supporting

Mentioning

210

Contrasting

Unclassified

Order By: Relevance

“…The total CV for method 1 used over a period of one year (n = 122) was also generally comparable (tFOL < 3%, 5-methylTHF < 3%, MeFox < 7%, 5,10-methenylTHF ≤ 8%, 5-formylTHF ≤ 10%), except for a few analytes where it was higher (THF ≤ 13%, FA ≤ 17%) (data not shown). It has been suggested that generally applicable quality goals based on biologic variation should be used to assess whether the method precision is acceptable; the analytical variation CV a should be a fraction of the within-person biologic variation CV w : optimum performance, CV a = 0.25 × CV w , desirable performance, CV a = 0.5 × CV w , minimum performance, CV a = 0.75 × CV w [22]. Using data from NHANES 1999-2002, serum (total) folate was reported to have a within-person biologic variation of 21.5% [23].…”

Section: Resultsmentioning

confidence: 99%

A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product

et al. 2013

View full text Add to dashboard Cite

Small specimen volume and high sample throughput are key features needed for routine methods used for population biomonitoring. We modified our routine 8-probe solid phase extraction (SPE) LC-MS/MS method for the measurement of five folate vitamers (5-methyltetrahydrofolate , folic acid [FA], plus three minor forms: THF, 5-formylTHF, 5,10-methenylTHF) and one oxidation product of 5-methylTHF (MeFox) to require less serum volume (150 μL instead of 275 μL) by using 96-well SPE plates with 50-mg instead of 100-mg phenyl sorbent and to provide faster throughput by using a 96-probe SPE system. Total imprecision (10 days, 2 replicates/day) for three serum quality control (QC) pools was 2.8-3.6% for 5-methylTHF (19.5-51.1 nmol/L), 6.6-8.7% for FA (0.72-11.4 nmol/L), and ≤11.4% for the minor folate forms (<1-5 nmol/L). Mean (±SE) recovery of folates spiked into serum (3 days, 4 levels, 2 replicates/level) was: 5-methylTHF, 99.4±3.6%; FA, 100±1.8%; minor folates, 91.7-108%); SPE extraction efficiencies were ≥85% except for THF (78%). Limits of detection were ≤0.3 nmol/L. The new method correlated well with our routine method (n=150; r=0.99 for 5-methylTHF, FA, and total folate [tFOL, sum of folate forms]) and produced slightly higher tFOL (5.6%) and 5-methylTHF (7.3%) concentrations, likely due to the faster 96-probe SPE process (1 vs. 5 h) resulting in improved SPE efficiency and recovery compared to the 8-probe SPE method. With this improved LC-MS/MS method, 96 samples can be processed in ~2 h and all relevant folate forms can be accurately measured using a small serum volume.

show abstract

Section: Resultsmentioning

confidence: 99%

A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Fraser et al [24] indicate a desirable coefficient for total imprecision 0.5 Â CV within-subject : Since the within-subject variation of homocysteine is about 8.5% [25], the total imprecision of this method is acceptable in the range of the concentration studied.…”

Section: Discussionmentioning

confidence: 97%

A simplified method for the determination of total homocysteine in plasma by electrospray tandem mass spectrometry

Persichilli

Gervasoni

Iavarone

et al. 2010

J of Separation Science

View full text Add to dashboard Cite

A simplified method for the determination of total homocysteine in plasma by electrospray tandem mass spectrometry Hyperhomocysteinemia is a risk factor for different diseases. Several methods have been developed to analyze homocysteine and the immunometric ones, although expensive, they are in widespread use. A rapid LC-MS/MS method for homocysteine assay has been developed for the application of large clinical chemistry routines. Selected reaction monitoring was performed through the transitions m/z 136.0-90.1 for homocysteine and m/z 140.0-94.0 for the internal standard. ESI was used to generate [H1] adduct ions. Chromatographic isocratic separation was achieved using a strong cation exchange column. The mobile phase was methanol/water (20:80 v/v, containing 0.1% formic acid and 1.5 mmol/L ammonium formate in the water phase) at a flow rate of 0.250 mL/min (351C). Samples treatment consisted in the reduction with DTT and deproteinization with methanol. Recovery, linearity, LOD, LOQ and total imprecision were evaluated to validate the method. Homocysteine values on 100 serum samples were compared with those obtained by HPLC and immunometric methods. The method is robust, selective and precise in the whole range of values studied. Moreover, low reagent cost and easiness of sample treatment make this method useful, not only for research, but also for routine work.

show abstract

“…electrolytes), lending themselves to very strict performance specifications. Three quality levels are used for imprecision and bias [27].…”

Section: Performance Specificationsmentioning

confidence: 99%

The use of error and uncertainty methods in the medical laboratory

Oosterhuis

Bayat²,

Armbruster

et al. 2017

Clinical Chemistry and Laboratory Medicine (CCLM)

View full text Add to dashboard Cite

Error methods -compared with uncertainty methods -offer simpler, more intuitive and practical procedures for calculating measurement uncertainty and conducting quality assurance in laboratory medicine. However, uncertainty methods are preferred in other fields of science as reflected by the guide to the expression of uncertainty in measurement. When laboratory results are used for supporting medical diagnoses, the total uncertainty consists only partially of analytical variation. Biological variation, pre-and postanalytical variation all need to be included. Furthermore, all components of the measuring procedure need to be taken into account. Performance specifications for diagnostic tests should include the diagnostic uncertainty of the entire testing process. Uncertainty methods may be particularly useful for this purpose but have yet to show their strength in laboratory medicine. The purpose of this paper is to elucidate the pros and cons of error and uncertainty methods as groundwork for future consensus on their use in practical performance specifications. Error and uncertainty methods are complementary when evaluating measurement data.

show abstract

Proposals for Setting Generally Applicable Quality Goals Solely Based on Biology

Cited by 319 publications

References 15 publications

A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product

A high-throughput LC-MS/MS method suitable for population biomonitoring measures five serum folate vitamers and one oxidation product

A simplified method for the determination of total homocysteine in plasma by electrospray tandem mass spectrometry

The use of error and uncertainty methods in the medical laboratory

Contact Info

Product

Resources

About