Defining analytical performance specifications 15 years after the Stockholm conference.

The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has as part of its mission “to be the leading organization of Laboratory Medicine in Europe.” Through leadership, the EFLM strives to enhance patient care and improve outcomes by promoting and improving the scientific, professional and clinical aspects of laboratory medicine. To focus on important aspects in laboratory medicine in which some strategic actions and measures should be taken, the EFLM decided to start a biannual series of conferences. The first edition was held in Milan, Italy, on November 2014. The conference was entitled “Defining analytical performance goals 15 years after the Stockholm conference” as it was considered timely to address the topic of performance specifications both because it was a long time since it was previously addressed and because performance specifications are central for the clinical application of test measurements and are also of vital importance for quality control measures that should be taken in the laboratories. The conference, organized in cooperation with the Centre for Metrological Traceability in Laboratory Medicine (CIRME) of the University of Milan and the Institute for Reference Materials and Measurements (IRMM) of the European CommissionJoint Research Centre, was very successful, with 215 participants from 41 different countries, embracing the five continents (the complete list of conference participants is available as electronic Supplementary Material that accompanies the article at http://www.degruyter. com/view/j/cclm.2015.53.issue-6/cclm-2015-0303/cclm2015-0303.xml?format=INT). The delegates came from clinical laboratories, from EQAS providers and other professional organizations as well as from the in vitro diagnostics (IVD) manufacturers. In this issue of Clinical Chemistry and Laboratory Medicine all contributions given during the conference are published (the slides of presentations are available online at http://www.efcclm. eu/index.php/educational-material.html). The Stockholm Conference in 1999 was a landmark in trying to achieve a consensus on how quality specifications should be set and a hierarchy of models was established [1]. In his paper, Callum Fraser gives not only a historic review of the 1999 Conference, where he served as a cochair, but also a general survey of the history of laboratory quality specifications [2]. He underlines that time has come to revisit this hierarchy, investigating to what extent it is still valid or if it should be modified or expanded, which is the ultimate goal of the EFLM conference. The conference comprised five sessions. The first three sessions examined the possibility and the pros and cons to base performance specifications on clinical needs, on biological variation data or on state-of-the-art of the measurement procedure, respectively. In their article on behalf of the EFLM Working Group (WG) on Test Evaluation, Horvath et al. [3] discuss the complexity of outcomerelated models in a way that allows investigation of the impact of analytical performance on medical decisions and patient management. Whilst it is acknowledged that these types of evaluations are difficult and may not be possible for all measurands in laboratory medicine, the authors consider this approach as the “gold standard” for setting specifications. Next, Per Hyltoft Petersen, another one of the 1999 conference organizers, expanded the discussion to cover the use of simulation studies as a way to model the probability of clinical outcome and the impact of analytical performance upon them [4]. As an example, the influence of analytical performance is investigated for diagnosing of diabetes using hemoglobin A1c and for individuals at risk for coronary heart disease as defined by serum cholesterol concentrations. In another article, Thue and Sandberg address the topic of performance specifications based on how clinicians use laboratory tests [5]. These authors comment, however, that there is a large variability among clinician behaviors that can limit the role of this approach and that it merely reflects the expectations of the clinicians rather than the ultimate specifications that should be set. The group of Ricos reviews the rationale for using data on biological variation to derive analytical specifications