Commutability of external quality assessment materials for point‐of‐care glucose testing using the Clinical and Laboratory Standards Institute and International Federation of Clinical Chemistry approaches

Abstract

Objectives The aim of this study was to assess the commutability of three external quality assessment (EQA) materials for point‐of‐care (POC) glucose testing using two approaches, to identify suitable EQA materials to evaluate and monitor the quality of POC testing. Methods Commercial control materials (CCMs), pooled human serum samples (PHSs), and homemade human whole‐blood samples (HWBs) were measured along with 33 individual clinical samples using five POC instruments and a Hitachi 7600 analyzer. Data were analyzed by Deming regression analysis with a 95% prediction interval as described in Clinical and Laboratory Standards Institute (CLSI) EP30‐A, and by difference in bias analysis as described by the International Federation of Clinical Chemistry (IFCC) Working Group on Commutability. Results Using the CLSI approach, HWBs, CCMs, and PHSs were commutable with five, one, and two instruments, respectively. With the IFCC approach, HWBs were commutable with two instruments, while CCMs and PHSs were largely inconclusive or non‐commutable on five instruments. Conclusions HWBs were commutable on all instruments by the CLSI approach and may be a suitable EQA material for POC testing. Although some results differed between the IFCC and CLSI approaches, both indicated that HWBs were far superior to CCMs and PHSs in commutability.

Quality assessment of glucose measurement with regard to epidemiology and clinical management of diabetes mellitus in Germany

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Commutability evaluation of candidate reference materials and ERM‐DA470k/IFCC for immunoglobulin M using two international approaches

“…The CLSI approach mainly depends on visual inspection to judge whether the materials has commutability in the analysis combinations, and the judgment of points falling on the 95% line is subjective 29 . Moreover, if there are outliers in the serum panel that are not removed, 95% PI will be widened, resulting in some non‐commutable material being commutable.…”

Standardization and harmonization in hematology: Instrument alignment, quality control materials, and commutability issue

“…The historical CLSI approach to assess the commutability of control materials, commonly used so far, presents some limitation, and recently, it has been replaced by a new approach recommended by the IFCC 35 . The commutability is a property required to provide an EQAS program classified as category 1 or 2, and without proven commutability the key benefit of assessment of traceability of the result to a reference system is lost, 36 as shown by comparing the results obtained from traditional schemes using both serum matrix control materials 37,38 and whole‐blood control materials 39 .…”

“…The commutability is a property required to provide an EQAS program classified as category 1 or 2, and without proven commutability the key benefit of assessment of traceability of the result to a reference system is lost, 36 as shown by comparing the results obtained from traditional schemes using both serum matrix control materials 37,38 and whole‐blood control materials 39 . The commutability of some whole‐blood EQAS control materials has been recently evaluated using the new IFCC approach, pursued for point of care testing, including only Hb as hematologic parameter 35‐40 . Conversely, at least to our knowledge, the commutability property of control materials used for hematologic analyzers alignment is not usually verified.…”