DOI 10.1515/cclm-2012-0840 Clin Chem Lab Med 2013; aop Opinion Paper Nuthar Jassam*, John Yundt-Pacheco, Rob Jansen, Annette Thomas and Julian H. Barth Can current analytical quality performance of UK clinical laboratories support evidence-based guidelines for diabetes and ischaemic heart disease? – A pilot study and a proposal Abstract Background: The implementation of national and inter- national guidelines is beginning to standardise clinical practice. However, since many guidelines have decision limits based on laboratory tests, there is an urgent need to ensure that different laboratories obtain the same ana- lytical result on any sample. A scientifically-based quality control process will be a pre-requisite to provide this level of analytical performance which will support evidence- based guidelines and movement of patients across bound- aries while maintaining standardised outcomes. We discuss the finding of a pilot study performed to assess UK clinical laboratories readiness to work to a higher grade quality specifications such as biological variation-based quality specifications. Methods: Internal quality control (IQC) data for HbA 1c , glucose, creatinine, cholesterol and high density lipo- protein (HDL)-cholesterol were collected from UK labora- tories participating in the Bio-Rad Unity QC programme. The median of the coefficient of variation (CV%) of the participating laboratories was evaluated against the CV% based on biological variation. Results: Except creatinine, the other four analytes had a variable degree of compliance with the biological varia- tion-based quality specifications. More than 75% of the laboratories met the biological variation-based quality specifications for glucose, cholesterol and HDL-choles- terol. Slightly over 50% of the laboratories met the ana- lytical goal for HBA 1c . Only one analyte (cholesterol) had a performance achieving the higher quality specifications consistent with 5 σ. Conclusions: Our data from IQC do not consistently dem- onstrate that the results from clinical laboratories meet evidence-based quality specifications. Therefore, we propose that a graded scale of quality specifications may be needed at this stage. Keywords: analytical performance; internal quality control; σ metric. *Corresponding author: Nuthar Jassam, Department of Clinical Biochemistry, Harrogate District Foundation Trust, Lancaster Park Road, Harrogate, HG2 7SX, UK, E-mail: nuthar@hdft.nhs.uk John Yundt-Pacheco: Bio-Rad Laboratories, Quality System Division, Plano, Fairview, TX, USA Rob Jansen: Dutch Foundations for Quality Assessment in Clinical Laboratories (SKML), Nijmegen, The Netherlands Annette Thomas: WEQAS Quality Laboratory, Cardiff and Vale University Health Board, Cardiff, UK Julian H. Barth: Blood Sciences, Old Medical School, Leeds Teaching Hospitals Trust, Leeds, UK Introduction Many international guidelines include laboratory test values with which diseases are diagnosed or clinical man- agement decisions are made. In general these guidelines have been based on one or more studies for which labo- ratory support has been provided by one laboratory using a single analytical method, sometimes operating under batch conditions. When these guidelines are translated into clinical practice, patients’ blood samples are judged against these target values, yet they are measured with a plethora of methods and platforms using different batches of reagents over long periods of time. All these methods are prone to within- and between-batch variations as well as between-laboratory variation and between-method bias. Laboratory specialists are aware of the between-labora- tory variation and -method bias through external quality assurance (EQA) reports, but these only tell half the story. Indeed, the total analytical imprecision may be much more problematic and lead to considerable patient safety issues that are as equally important as prescribing errors.