Lower creatinine concentration values and lower inter-laboratory variation among Swedish hospital laboratories in 2014 compared to 1996 : results from the Equalis external quality assessment program

• Background:Creatinine measurement for estimation of glomerular filtration rate (GFR) is a frequently used laboratory test. Differences in analytic creatinine methods have caused large inter-laboratory variation. International and national standardization efforts have been made in the last decade.Methods:This study describes the results of the standardization efforts in Sweden by summarizing data for creatinine concentration in blood plasma in the Equalis quality assessment program during 1996-2014.Results:Non-compensated Jaffe methods dominated in 1996-2001 (91 of 103 laboratories; 90%) and were then gradually replaced by either compensated Jaffe methods or enzymatic creatinine methods. In 2014 a majority of Swedish hospital laboratories (139 of 159; 87%) used enzymatic methods. The reported mean creatinine value by the Swedish laboratories was about 10 mu mol/L higher than the isotope dilution mass spectrometry (IDMS) assured reference value in 2003, but consistent with the reference value from 2009 to 2014. The inter-laboratory CV was 7%-9% for creatinine values until 2007, and thereafter gradually decreased to about 4%-5% in 2014.Conclusions:The introduction of enzymatic methods in Swedish laboratories has contributed to achieving a low inter-laboratory variation. Also, the reported values are lower for enzymatic methods compared to Jaffe methods, and the values obtained with enzymatic methods were consistent with IDMS certified values established at reference laboratories. Thus, many Swedish hospital laboratories reported 10 mu mol/L lower, and more true, creatinine concentrations in 2012 than in 2003, which may cause bias in longitudinal studies.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Klinisk laboratoriemedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Clinical Laboratory Medicine (hsv//eng)

Nyckelord

creatinine methods

external quality assessment

harmonization

inter-laboratory variation

standardization

Publikations- och innehållstyp

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