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Licensed Unlicensed Requires Authentication Published by De Gruyter July 10, 2009

Haemolysis index – an estimate of preanalytical quality in primary health care

Johan Söderberg, P. Andreas Jonsson, Olof Wallin, Kjell Grankvist and Johan Hultdin


Background: Haemolysis is usually caused by inadequate specimen collection or preanalytical handling, and is suggested to be a suitable indicator of pre-analytical quality. We investigated the prevalence of detectable haemolysis in all routine venous blood samples to identify differences in preanalytical quality.

Methods: Haemolysis index (HI) values were obtained from a Vitros 5,1 in the routine clinical chemistry laboratory for samples collected in primary health care centres (PHCs), nursing homes, and a hospital emergency department (ED). Haemolysis was defined as a HI ≥15 (detection limit).

Results: Samples from the PHC with the highest prevalence of haemolysis were 6.1 times (95% confidence interval (CI) 4.0–9.2) more often haemolysed compared to the centre with the lowest prevalence. Of the samples collected in primary health care, 10.4% were haemolysed compared to 31.1% in the ED (p<0.001). A notable difference in haemolysed samples was found between the ED section staffed by emergency medicine physicians and the section staffed by primary health care physicians (34.8% vs. 11.3%, p<0.001).

Conclusions: The significant variation in haemolysis indices among the investigated units is likely to reflect varying preanalytical conditions. The HI is a valuable tool for estimation and follow-up of preanalytical quality in primary health care.

Clin Chem Lab Med 2009;47:940–4.

Corresponding author: Johan Söderberg, Department of Medical Biosciences, Clinical Chemistry, Umeå University, Building 6M 2nd floor, 901 85 Umeå, Sweden Phone: +46-90-7852841, Fax: +46-90-7854484,

Received: 2009-4-7
Accepted: 2009-5-25
Published Online: 2009-07-10
Published in Print: 2009-08-01

©2009 by Walter de Gruyter Berlin New York

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