Critical appraisal and meta-analysis of biological variation estimates for kidney related analytes.

Objectives: Kidney markers are some of the most frequently used laboratory tests in patient care, and correct clinical decision making depends upon knowledge and correct application of biological variation (BV) data. The aim of this study was to review available BV data and to provide updated BV estimates for the following kidney markers in serum and plasma; albumin, creatinine, cystatin C, chloride, potassium, sodium and urea.

Content: Relevant studies were identified from a historical BV database as well as by systematic literature searches.

Standardization in laboratory medicine: Two years' experience from category 1 EQA programs in Spain.

Introduction: Standardization is the ability to obtain interchangeable results leading to same medical interpretation. External quality assessment (EQA) is the main support of the on-going harmonization initiatives. Aim of study was to evaluate results obtained from two years category 1 EQA program experience in Spain and determine the impact of applying this type of EQA program on the analytical standardization.

Laboratory sample stability. Is it possible to define a consensus stability function? An example of five blood magnitudes.

Background: The stability limit of an analyte in a biological sample can be defined as the time required until a measured property acquires a bias higher than a defined specification. Many studies assessing stability and presenting recommendations of stability limits are available, but differences among them are frequent. The aim of this study was to classify and to grade a set of bibliographic studies on the stability of five common blood measurands and subsequently generate a consensus stability function.

The Biological Variation Data Critical Appraisal Checklist: A Standard for Evaluating Studies on Biological Variation.

Background: Concern has been raised about the quality of available biological variation (BV) estimates and the effect of their application in clinical practice. A European Federation of Clinical Chemistry and Laboratory Medicine Task and Finish Group has addressed this issue. The aim of this report is to () describe the Biological Variation Data Critical Appraisal Checklist (BIVAC), which verifies whether publications have included all essential elements that may impact the veracity of associated BV estimates, () use the BIVAC to critically appraise existing BV publications on enzymes, lipids, kidney, and diabetes-related measurands, and () apply metaanalysis to deliver a global within-subject BV (CV) estimate for alanine aminotransferase (ALT).

Category 1 external quality assessment program for serum creatinine.

Background: The Commission of Analytical Quality and the Committee of External Quality Programs of Spanish Society of Laboratory Medicine (SEQC) in collaboration with the Dutch Foundation for the Quality organized the first national category 1 External Quality Assessment Programs (EQAP) pilot study. The aim is to evaluate the standardization of serum creatinine measurements in the Spanish laboratories through a category 1 external quality assurance program with commutable material and reference method assigned values.

Methods: A total of 87 Spanish laboratories were involved in this program in 2015.

Biologic Variation Approach to Daily Laboratory.

Biological variation gives valuable information about how the living organism regulates its constituents within and between subjects; this information on the behavior of body components allows us to derive consequences concerning reference populations and intervals. With a more pragmatic approach biological variation has three uses: setting the appropriate analytical performance specification for each analyte to limit the amount of error that laboratory could introduce in its measurements, to help distinguish health from disease, and to implement internal quality control with the automatic verification of results.

Spanish Preanalytical Quality Monitoring Program (SEQC), an overview of 12 years' experience.

Background: Preanalytical variables, such as sample collection, handling and transport, may affect patient results. Preanalytical phase quality monitoring should be established in order to minimize laboratory errors and improve patient safety.

Methods: A retrospective study (2001-2013) of the results obtained through the Spanish Society of Clinical Biochemistry and Molecular Pathology (SEQC) External quality assessment (preanalytical phase) was performed to summarize data regarding the main factors affecting preanalytical phase quality.

Rationale for using data on biological variation.

The aims of this study are: 1) to use the data included in the biological variation (BV) database to address the usability of BV estimates; and 2) to use different examples from the authors' laboratories to illustrate the use and the usefulness of BV data in laboratory medicine. The BV database is an essential tool for laboratory management. Examples of application of data derived from BV are given in this paper, such as analytical performance specifications that have been included in various quality control software designed to optimize operative rules; also they have been incorporated as acceptability limits in external quality assurance reports.

Biological variation database: structure and criteria used for generation and update.

Background: Numerical data on the components of biological variation (BV) have many uses in laboratory medicine, including in the setting of analytical quality specifications, generation of reference change values and assessment of the utility of conventional reference values.

Methods: Generation of a series of up-to-date comprehensive database of components of BV was initiated in 1997, integrating the more relevant information found in publications concerning BV. A scoring system was designed to evaluate the robustness of the data included.

Harmonization in hemolysis detection and prevention. A working group of the Catalonian Health Institute (ICS) experience.

Background: Hemolysis is the main cause of non-quality samples in clinical laboratories, producing the highest percentage of rejections in the external assurance programs of preanalytical quality. The objective was to: 1) study the agreement between the detection methods and quantification of hemolysis; 2) establish comparable hemolysis interference limits for a series of tests and analytical methods; and 3) study the preanalytical variables which most influence hemolysis production.

Methods: Different hemoglobin concentration standards were prepared using the reference method.

Current status of verification practices in clinical biochemistry in Spain.

Background: Verification uses logical algorithms to detect potential errors before laboratory results are released to the clinician. Even though verification is one of the main processes in all laboratories, there is a lack of standardization mainly in the algorithms used and the criteria and verification limits applied. A survey in clinical laboratories in Spain was conducted in order to assess the verification process, particularly the use of autoverification.

Quality indicators and specifications for key analytical-extranalytical processes in the clinical laboratory. Five years' experience using the Six Sigma concept.

Background: The results of 5 years of experience (2004-2008) with process-based quality management using quality indicators for key laboratory processes (analytic and extra-analytic) in a group of clinical laboratories affiliated with the Catalan Health Institute are presented. Our purpose was to analyze the evolution of the indicators, identify processes that require corrective measures, and obtain specifications that are more robust than the preliminary ones proposed in a previous study by the same group.

Methods: The yearly average was recorded for each indicator in each laboratory, the yearly interlaboratory median was calculated, and the changes occurring were studied to determine their continuity in the 5-year period.

Indicators and quality specifications for strategic and support processes related to the clinical laboratory: four years' experience.

Background: Quality specifications for indicators of the key analytic processes have been defined by international consensus. However, only preliminary specifications for laboratory-related strategic and support processes have been developed. The present study attempts to increase the robustness of the preliminary proposed specifications.

Quality indicators and specifications for strategic and support processes in laboratory medicine.

Background: This work is the second part of a study regarding indicators and quality specifications for the non-analytical processes in laboratory medicine. Five primary care and five hospital laboratories agreed on the indicators for two strategic processes (quality planning and project development) and various support processes (client relationships, instrument and infrastructure maintenance, safety and risk prevention, purchases and storage, personnel training).

Methods: In the majority of cases, the median values recorded over 1 year is considered to be the state-of-the-art in our setting and proposed as the quality specification for the indicators stated.

Preanalytical quality control program - an overview of results (2001-2005 summary).

Background: Preanalytical variables, such as sample collection, handling, transport, and storage, may affect patient results. The number of errors in the preanalytical phase may decrease by following standardized procedures.

Methods: A retrospective analysis (2001-2005) of results obtained through the Spanish Society of Clinical Chemistry and Molecular Pathology Quality Assessment Program for the Preanalytical Phase has been carried out to summarize data regarding the main factors affecting the preanalytical phase quality.

Within-subject biological variation in disease: collated data and clinical consequences.

Quantitative data on the components of biological variation (BV) are used for several purposes, including calculating the reference change value (RCV) required for the assessment of the significance of changes in serial results in an individual. Pathology may modify the set point in diseased patients and, more importantly, the variation around that set-point. Our aim was to collate all published BV data in situations other than health.

Integration of data derived from biological variation into the quality management system.

Background: [corrected] Data on within- and between-subject biological variation are available for around 250 analytes commonly used in medical laboratories.

Methods: Integration of this data into the quality system occurs at all three levels of laboratory activity: (a) Preanalytic process: biological variation provides the basis for selecting the most appropriate specimen for analysis, for defining sample stability and for deciding suitable timing between samplings; (b) analytic process: biological variation-derived goals are fundamental for designing internal quality control procedures, and for evaluating laboratory performance; and (c) postanalytic process: delta checks based on within-subject biological variation values are used for validating results and for interpreting serial results from a patient.

Conclusion: The biological variation is a pillar for managing quality in laboratory medicine.