Application of biological variation - a review

Ovaj rad sadrži opsežan pregled sastavnica biološke varijacije (BV), tj. intraindividualne (nasumična fluktuacija analita oko osnovne vrijednosti svakog pojedinca) i interindividualne (ukupna varijacija od osnovnih vrijednosti različitih osoba) varijacije, zatim ukratko objašnjava procjenu veličine intraindividualne i interindividualne BV u zdravih i oboljelih ispitanika, podrobno obrađuje osam složenijih primjena procjena BV, te govori o zanimljivim detaljima koji izazivaju najviše rasprava. Cilj rada je raspraviti kako pomoću današnje tehnologije doći do specifikacija kvalitete dobivenih na temelju BV u zdravih pojedinaca te u kojim se slučajevima koristiti podacima od oboljelih ispitanika. Konačno, u radu se promiče daljnji razvoj primjene BV, poput upozoravanja liječnika o promjenama u bolesnikovu stanju.This paper introduces an extensive revision of the types of components of biological variation (BV), i.e. intraindividual (random fluctuation of analytes around the setting point of each individual) and interindividual (overall variation from the different person\u27s setting point), briefly explains estimation of the magnitude of within- and between subject BV in healthy and non-healthy subjects, details the eight common applications of BV estimates and discusses the most debated points of interests. The aim is to discuss how quality specifications derived from BV determined in healthy individuals are attainable with current technology and in what cases data from non-healthy subjects should be used. Finally, the paper promotes further development of BV application, such as notifying doctors about changes in patient status

Application of biological variation - a review

Ovaj rad sadrži opsežan pregled sastavnica biološke varijacije (BV), tj. intraindividualne (nasumična fluktuacija analita oko osnovne vrijednosti svakog pojedinca) i interindividualne (ukupna varijacija od osnovnih vrijednosti različitih osoba) varijacije, zatim ukratko objašnjava procjenu veličine intraindividualne i interindividualne BV u zdravih i oboljelih ispitanika, podrobno obrađuje osam složenijih primjena procjena BV, te govori o zanimljivim detaljima koji izazivaju najviše rasprava. Cilj rada je raspraviti kako pomoću današnje tehnologije doći do specifikacija kvalitete dobivenih na temelju BV u zdravih pojedinaca te u kojim se slučajevima koristiti podacima od oboljelih ispitanika. Konačno, u radu se promiče daljnji razvoj primjene BV, poput upozoravanja liječnika o promjenama u bolesnikovu stanju.This paper introduces an extensive revision of the types of components of biological variation (BV), i.e. intraindividual (random fluctuation of analytes around the setting point of each individual) and interindividual (overall variation from the different person\u27s setting point), briefly explains estimation of the magnitude of within- and between subject BV in healthy and non-healthy subjects, details the eight common applications of BV estimates and discusses the most debated points of interests. The aim is to discuss how quality specifications derived from BV determined in healthy individuals are attainable with current technology and in what cases data from non-healthy subjects should be used. Finally, the paper promotes further development of BV application, such as notifying doctors about changes in patient status

Biological variation data for lipid cardiovascular risk assessment biomarkers:A systematic review applying the biological variation data critical appraisal checklist (BIVAC)

Background: Biological variation (BV) data can be used to set analytical performance specifications (APS) for lipid assays. Poor performance will impact upon the efficacy of international guidelines for cardiovascular risk assessment (CVR) and relevant clinical decision limits. This systematic review applies the Biological Variation Data Critical Appraisal Checklist (BIVAC) to published studies of BV of CVR biomarkers enabling metanalysis of the data. Methods: Studies of BV of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and apolipoproteins A1 and B, retrieved using a systematic literature search, were evaluated and graded using the BIVAC. Meta-analysis of CVI and CVG estimates were performed utilizing weightings based upon BIVAC grades and the width of the data confidence intervals. Results: Applying the BIVAC, ten publications were graded as D, 43 as C, 5 as B and 1 as A (fully compliant). A total of 196 CVI and 87 CVG estimates were available for the different lipid measurands. The meta-analysis-derived BV data estimates were generally concordant with those in the online 2014 BV database. Conclusions: Application of BIVAC identifies BV data suitable for many important applications including setting APS. Additionally, this review identifies a need for new BIVAC compliant studies to deliver BV reference data in different subpopulations

Systematic review and meta-analysis of within-subject and between-subject biological variation estimates of 20 haematological parameters

Interpretation of the complete blood count (CBC) parameters requires reliable biological variation (BV) data. The aims of this study were to appraise the quality of publications reporting BV data for CBC parameters by applying the BV Data Critical Appraisal Checklist (BIVAC) and to deliver global BV estimates based on BIVAC compliant studies. Relevant publications were identified by a systematic literature search and evaluated for their compliance with the 14 BIVAC criteria, scored as A, B, C or D, indicating decreasing compliance. Global CVI and CVG estimates with 95% CI were delivered by a meta-analysis approach using data from BIVAC compliant papers (grades A-C). In total, 32 studies were identified; four received a BIVAC grade A, 2 B, 20 C and 6 D. Meta-analysis derived CVI and CVG estimates were generally lower or in line with those published in a historical BV database available online. Except for reticulocytes, CVI estimates of erythrocyte related parameters were below 3%, whereas platelet (except MPV and PDW) and leukocyte related parameters ranged from 5% to 15%. A systematic review of CBC parameters has provided updated, global estimates of CVI and CVG that will be included in the newly published European Federation of Clinical Chemistry and Laboratory Medicine BV Database.</p

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. Materials and methods: According to the analytical method, traceability and instrument different groups were established which results were evaluated by calculating mean, coefficient of variation and percent of deviation to the reference value. Analytical performance specifications used to the results\u27 evaluation were derived from biological variation for bias and from the inter-laboratory coefficients of variation found in a previous pilot study. Results: Only creatinine measured by enzymatic methods gave excellent results, although few laboratories used this method. Creatine kinase and GGT gave good precision and bias in all, but one instrument studied. For the remaining analytes (ALT, ALP, AST, bilirubin, calcium, chloride, glucose, magnesium, potassium, sodium, total protein and urate) some improvement is still necessary to achieve satisfactory standardization in our setting. Conclusions: The two years of category 1 EQA program experience in Spain have manifested a lack of standardization of 17 most frequent biochemistry tests used in our laboratories. The impact of the information obtained on the lack of standardization is to recommend abandoning methods such as ALT, AST without exogenous pyridoxal phosphate, Jaffe method for creatinine, and do not use non-commutable calibrators, such as aqueous solutions for calcium and sodium

External quality control in laboratory medicine. Progresses and future

An external quality control program distributes same control samples to various laboratories and evaluates results obtained with a common criterion. The aim of this work is to summarize the evolution of various types of external programs, to point out the progresses ant to preclude practical consequences of the participant laboratories

Control externo de la calidad en medicina del laboratorio. Avances y futuro

Un programa de control externo distribuye las mismas muestras control entre varios laboratorios y evalúa los resultados obtenidos con un criterio común. El objetivo de este trabajo es resumir la evolución de los programas externos, poner de manifiesto los progresos conseguidos y deducir consecuencias prácticas para el laboratorio participante

Control interno de la calidad – bases del pasado, situación presente y futuras tendencias

Este artículo ofrece una síntesis de los modelos de control interno de la calidad analítica usados, desde mediados del siglo XX hasta los que están en vigor actualmente y pretende dar una proyección de cómo debería ser el futuro en esta materia concreta

Internal quality control – past, present and future trends

This paper offers an historical view, through a summary of the internal quality control (IQC) models used from second half of twentyth century to those performed today and wants to give a projection on how the future should be addressed