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Clinical Chemistry and Laboratory Medicine (CCLM)

Published in Association with the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)

Editor-in-Chief: Plebani, Mario

Ed. by Gillery, Philippe / Greaves, Ronda / Lackner, Karl J. / Lippi, Giuseppe / Melichar, Bohuslav / Payne, Deborah A. / Schlattmann, Peter


IMPACT FACTOR 2018: 3.638

CiteScore 2018: 2.44

SCImago Journal Rank (SJR) 2018: 1.191
Source Normalized Impact per Paper (SNIP) 2018: 1.205

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1437-4331
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Volume 53, Issue 9

Issues

Benchmarking by HbA1c in a national diabetes quality register – does measurement bias matter?

Siri Carlsen / Geir Thue
  • Norwegian Center for Quality Improvement of Primary Care Laboratories (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
  • Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ John Graham Cooper
  • Department of Medicine, Stavanger University Hospital, Stavanger, Norway
  • Norwegian Center for Quality Improvement of Primary Care Laboratories (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Thomas Røraas
  • Norwegian Center for Quality Improvement of Primary Care Laboratories (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
  • Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Lasse Gunnar Gøransson / Karianne Løvaas
  • Norwegian Center for Quality Improvement of Primary Care Laboratories (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
  • Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Sverre Sandberg
  • Norwegian Center for Quality Improvement of Primary Care Laboratories (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
  • Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway
  • Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
Published Online: 2014-12-12 | DOI: https://doi.org/10.1515/cclm-2014-0872

Abstract

Background: Bias in HbA1c measurement could give a wrong impression of the standard of care when benchmarking diabetes care. The aim of this study was to evaluate how measurement bias in HbA1c results may influence the benchmarking process performed by a national diabetes register.

Methods: Using data from 2012 from the Norwegian Diabetes Register for Adults, we included HbA1c results from 3584 patients with type 1 diabetes attending 13 hospital clinics, and 1366 patients with type 2 diabetes attending 18 GP offices. Correction factors for HbA1c were obtained by comparing the results of the hospital laboratories’/GP offices’ external quality assurance scheme with the target value from a reference method.

Results: Compared with the uncorrected yearly median HbA1c values for hospital clinics and GP offices, EQA corrected HbA1c values were within ±0.2% (2 mmol/mol) for all but one hospital clinic whose value was reduced by 0.4% (4 mmol/mol). Three hospital clinics reduced the proportion of patients with poor glycemic control, one by 9% and two by 4%.

Conclusions: For most participants in our study, correcting for measurement bias had little effect on the yearly median HbA1c value or the percentage of patients achieving glycemic goals. However, at three hospital clinics correcting for measurement bias had an important effect on HbA1c benchmarking results especially with regard to percentages of patients achieving glycemic targets. The analytical quality of HbA1c should be taken into account when comparing benchmarking results.

This article offers supplementary material which is provided at the end of the article.

Keywords: adult; analytical bias; benchmarking; diabetes mellitus; HbA1c; medical quality register

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About the article

Corresponding author: Siri Carlsen, Gandsveien 30, 4017 Stavanger, Norway, Phone: +47 95087620, Fax: +47 51519703, E-mail: ; and Department of Medicine, Stavanger University Hospital, Stavanger, Norway


Received: 2014-09-01

Accepted: 2014-11-13

Published Online: 2014-12-12

Published in Print: 2015-08-01


Citation Information: Clinical Chemistry and Laboratory Medicine (CCLM), Volume 53, Issue 9, Pages 1433–1439, ISSN (Online) 1437-4331, ISSN (Print) 1434-6621, DOI: https://doi.org/10.1515/cclm-2014-0872.

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[1]
Philippe Gillery
Clinical Chemistry and Laboratory Medicine (CCLM), 2015, Volume 53, Number 9

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