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Diagnosis (Berlin, Germany) Mar 2019Several lines of evidence now confirm that the vast majority of errors in laboratory medicine occur in the extra-analytical phases of the total testing processing,... (Review)
Review
Several lines of evidence now confirm that the vast majority of errors in laboratory medicine occur in the extra-analytical phases of the total testing processing, especially in the preanalytical phase. Most importantly, the collection of unsuitable specimens for testing (either due to inappropriate volume or quality) is by far the most frequent source of all laboratory errors, thus calling for urgent strategies for improving blood sample quality and managing data potentially generated measuring unsuitable specimens. A comprehensive overview of scientific literature leads us to conclude that hemolyzed samples are the most frequent cause of specimen non-conformity in clinical laboratories (40-70%), followed by insufficient or inappropriate sample volume (10-20%), biological samples collected in the wrong container (5-15%) and undue clotting (5-10%). Less frequent causes of impaired sample quality include contamination by infusion fluids (i.e. most often saline or glucose solutions), cross-contamination of blood tubes additives, inappropriate sample storage conditions or repeated freezing-thawing cycles. Therefore, this article is aimed to summarize the current evidence about the most frequent types of unsuitable blood samples, along with tentative recommendations on how to prevent or manage these preanalytical non-conformities.
Topics: Blood Chemical Analysis; Blood Specimen Collection; Hemolysis; Humans; Laboratories; Medical Errors; Pre-Analytical Phase
PubMed: 29794250
DOI: 10.1515/dx-2018-0018 -
Biochemia Medica Feb 2021Calculating the sample size in scientific studies is one of the critical issues as regards the scientific contribution of the study. The sample size critically affects...
Calculating the sample size in scientific studies is one of the critical issues as regards the scientific contribution of the study. The sample size critically affects the hypothesis and the study design, and there is no straightforward way of calculating the effective sample size for reaching an accurate conclusion. Use of a statistically incorrect sample size may lead to inadequate results in both clinical and laboratory studies as well as resulting in time loss, cost, and ethical problems. This review holds two main aims. The first aim is to explain the importance of sample size and its relationship to effect size (ES) and statistical significance. The second aim is to assist researchers planning to perform sample size estimations by suggesting and elucidating available alternative software, guidelines and references that will serve different scientific purposes.
Topics: Data Interpretation, Statistical; Laboratories; Models, Theoretical; Sample Size; Software
PubMed: 33380887
DOI: 10.11613/BM.2021.010502 -
Journal of Virology Aug 2021Starting work in a virology research laboratory as a new technician, graduate student, or postdoc can be complex, intimidating, confusing, and stressful. From laboratory...
Starting work in a virology research laboratory as a new technician, graduate student, or postdoc can be complex, intimidating, confusing, and stressful. From laboratory logistics to elemental expectations to scientific specifics, there is much to learn. To help new laboratory members adjust and excel, a series of guidelines for working and thriving in a virology laboratory is presented. While guidelines may be most helpful for new laboratory members, everyone, including principal investigators, is encouraged to use a set of published guidelines as a resource to maximize the time and efforts of all laboratory members. The topics covered here are safety, wellness, balance, teamwork, integrity, reading, research, writing, speaking, and timelines.
Topics: Guidelines as Topic; Humans; Laboratories; Research Design; Research Personnel; Virology
PubMed: 34319158
DOI: 10.1128/JVI.01112-21 -
Clinical Chemistry and Laboratory... Apr 2023Lot-to-lot verification is an integral component for monitoring the long-term stability of a measurement procedure. The practice is challenged by the resource... (Review)
Review
Lot-to-lot verification is an integral component for monitoring the long-term stability of a measurement procedure. The practice is challenged by the resource requirements as well as uncertainty surrounding experimental design and statistical analysis that is optimal for individual laboratories, although guidance is becoming increasingly available. Collaborative verification efforts as well as application of patient-based monitoring are likely to further improve identification of any differences in performance in a relatively timely manner. Appropriate follow up actions of failed lot-to-lot verification is required and must balance potential disruptions to clinical services provided by the laboratory. Manufacturers need to increase transparency surrounding release criteria and work closer with laboratory professionals to ensure acceptable reagent lots are released to end users. A tripartite collaboration between regulatory bodies, manufacturers, and laboratory medicine professional bodies is key to developing a balanced system where regulatory, manufacturing, and clinical requirements of laboratory testing are met, to minimize differences between reagent lots and ensure patient safety. has served as a fertile platform for advancing the discussion and practice of lot-to-lot verification in the past 60 years and will continue to be an advocate of this important topic for many more years to come.
Topics: Humans; Quality Control; Reagent Kits, Diagnostic; Chemistry, Clinical; Laboratories
PubMed: 36420533
DOI: 10.1515/cclm-2022-1126 -
Journal of the American College of... Jan 2021
Topics: Cardiac Catheterization; Cardiology; Echocardiography; Functional Laterality; Humans; Laboratories; Motor Skills
PubMed: 33413946
DOI: 10.1016/j.jacc.2020.11.042 -
Fertility and Sterility Jan 2022Delivery of fertility treatment involves both teamwork within a discipline as well as teaming across multiple work areas, such as nursing, administrative, laboratory,... (Review)
Review
Delivery of fertility treatment involves both teamwork within a discipline as well as teaming across multiple work areas, such as nursing, administrative, laboratory, and clinical. In contrast to small autonomous centers, the in vitro fertilization (IVF) laboratory team in large clinics must function both as a team with many members and a constellation of teams to deliver seamless, safe, and effective patient-centered care. Although this review primarily focuses on teamwork within the IVF laboratory, which comprises clinical laboratory scientists and embryologists who perform both diagnostic and therapeutic procedures, it also discusses the laboratory's wider role with other teams of the IVF clinic, and the role of teaming (the ad hoc creation of multidisciplinary teams) to function highly and address critical issues.
Topics: Female; Fertilization in Vitro; Humans; Interdisciplinary Communication; Laboratories; Male; Patient Care Team; Patient-Centered Care; Pregnancy; Reproductive Medicine
PubMed: 34763833
DOI: 10.1016/j.fertnstert.2021.09.031 -
Biochemia Medica Feb 2019Quantiles and percentiles represent useful statistical tools for describing the distribution of results and deriving reference intervals and performance specification in... (Review)
Review
Quantiles and percentiles represent useful statistical tools for describing the distribution of results and deriving reference intervals and performance specification in laboratory medicine. They are commonly intended as the sample estimate of a population parameter and therefore they need to be presented with a confidence interval (CI). In this work we discuss three methods to estimate CI on quantiles and percentiles using parametric, nonparametric and resampling (bootstrap) approaches. The result of our numerical simulations is that parametric methods are always more accurate regardless of sample size when the procedure is appropriate for the distribution of results for both extreme (2.5 and 97.5) and central (25, 50 and 75) percentiles and corresponding quantiles. We also show that both nonparametric and bootstrap methods suit well the CI of central percentiles that are used to derive performance specifications through quality indicators of laboratory processes whose underlying distribution is unknown.
Topics: Humans; Laboratories; Models, Statistical; Reference Values; Sample Size
PubMed: 30591808
DOI: 10.11613/BM.2019.010101 -
Clinical Chemistry and Laboratory... Mar 2017International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has established reference measurement procedures (RMPs) for the most popular enzymes.... (Review)
Review
International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has established reference measurement procedures (RMPs) for the most popular enzymes. Manufacturers should assign values to commercial calibrators traceable to these RMPs to achieve equivalent results in clinical samples, independent of reagent kits, instruments, and laboratory where the measurement is carried out. The situation is, however, far from acceptable. Some manufacturers continue to market assays giving results that are not traceable to internationally accepted RMPs. Meanwhile, end-users often do not abandon assays with demonstrated insufficient quality. Of the enzyme measurements, creatine kinase (CK) is satisfactorily standardized and a substantial improvement in performance of marketed γ-glutamyltranspeptidase (GGT) assays has been demonstrated. Conversely, aminotransferase measurements often exceed the desirable analytical performance because of the lack of pyridoxal-5-phosphate addition in the commercial reagents. Measurements of lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and α-amylase (AMY) still show major disagreement, suggesting the need for improvement in implementing traceability to higher-order references. This is mainly the result of using assays with different analytical selectivities for these enzymes. The definition by laboratory professionals of the clinically acceptable measurement uncertainty for each enzyme together with the adoption by EQAS of commutable materials and use of an evaluation approach based on trueness represent the way forward for reaching standardization in clinical enzymology.
Topics: Animals; Chemistry, Clinical; Clinical Enzyme Tests; Humans; Laboratories; Reference Standards
PubMed: 27718484
DOI: 10.1515/cclm-2016-0661 -
Clinical Chemistry and Laboratory... Dec 2018Thalassemia is one of the most common hereditary disorders of the developing world, and it is associated with severe anemia and transfusion dependence. The global health... (Review)
Review
Thalassemia is one of the most common hereditary disorders of the developing world, and it is associated with severe anemia and transfusion dependence. The global health burden of thalassemia has increased as a result of human mobility and migration in recent years. Depending on inherited mutations, thalassemia patients exhibit distorted hemoglobin (Hb) patterns and deviated red cell indices, both of which can be used to support identification by diagnostic tools. Diagnostic approaches vary depending on the target population and the aim of the testing. Current methods, which are based on Hb patterns, are used for first-line screening, whereas molecular testing is needed for conformation of the results and for prenatal and preimplantation genetic diagnosis. In the present paper, we review the diagnostic parameters, pitfalls, interfering factors, and methods; currently available best-practice guidelines; quality assurance and standardization of the procedures; and promising laboratory technologies for the future of thalassemia diagnosis.
Topics: Early Diagnosis; Female; Hemoglobins, Abnormal; Humans; Laboratories; Mutation; Pregnancy; Prenatal Diagnosis; Quality Assurance, Health Care; Thalassemia
PubMed: 30138112
DOI: 10.1515/cclm-2018-0647 -
Clinical Chemistry and Laboratory... Aug 2020The definition and enforcement of reference measurement systems, based on the implementation of metrological traceability of patient results to higher-order (reference)... (Review)
Review
The definition and enforcement of reference measurement systems, based on the implementation of metrological traceability of patient results to higher-order (reference) methods and/or materials, together with a clinically acceptable level of measurement uncertainty (MU), are fundamental requirements to produce accurate and equivalent laboratory results. The MU associated with each step of the traceability chain should be governed to obtain a final combined MU on clinical samples fulfilling the requested performance specifications. MU is useful for a number of reasons: (a) for giving objective information about the quality of individual laboratory performance; (b) for serving as a management tool for the medical laboratory and in vitro diagnostics (IVD) manufacturers, forcing them to investigate and eventually fix the identified problems; (c) for helping those manufacturers that produce superior products and measuring systems to demonstrate the superiority of those products; (d) for identifying analytes that need analytical improvement for their clinical use and ask IVD manufacturers to work for improving the quality of assay performance and (e) for abandoning assays with demonstrated insufficient quality. Accordingly, the MU should not be considered a parameter to be calculated by medical laboratories just to fulfill accreditation standards, but it must become a key quality indicator to describe both the performance of an IVD measuring system and the laboratory itself.
Topics: Biological Assay; Humans; Laboratories; Quality Control; Reference Standards; Uncertainty
PubMed: 32126011
DOI: 10.1515/cclm-2019-1336