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BACKGROUND: A new Rapid Drug Test Device (RDTD) is available for analysis of urine fentanyl. With the rise in fentanyl abuse in the United States, we evaluated the analytical performance of the RDTD test strip compared to mass spectrometry and 2 urine fentanyl immunoassays. METHODS: Leftover, deidentified urine samples collected from inpatients and outpatients from our psychiatric hospital and other clinics were frozen at <-70°C, thawed at room temperature, and centrifuged. Aliquots were tested with the RDTD (CLIA Waived, Inc.) test strips and 2 urine fentanyl immunoassays: the ARK Fentanyl II assay (ARK Diagnostics Inc.) and the Immunalysis SEFRIA Fentanyl assay (Immunalysis Corporation). Both assays were conducted on the Abbott Alinity c chemistry analyzer (Abbott Laboratories). Mass spectrometry analysis was performed at ARUP Laboratories. All assays had a 1â ng/mL positive cutoff. RESULTS: A total of 142 urine samples included 70 positive and 72 negative samples. The RDTD strips had lower sensitivity (84.3%) and efficiency (85.9%) and showed a specificity of 87.5% compared to the other assays. The ARK Fentanyl II assay showed identical sensitivity (95.7%) to the Immunalysis SEFRIA Fentanyl assay but had higher specificity (94.4% vs 81.9%) and overall efficiency (95.1% vs 88.7%). CONCLUSIONS: Differences were noted in the number of false negatives and positives among the assays. The RDTD demonstrated acceptable performance in detecting urine fentanyl in our patient population and would provide faster test results at point-of-care testing sites in our healthcare enterprise.
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Fentanilo , Espectrometría de Masas , Detección de Abuso de Sustancias , Fentanilo/orina , Humanos , Detección de Abuso de Sustancias/métodos , Detección de Abuso de Sustancias/instrumentación , Espectrometría de Masas/métodos , Inmunoensayo/métodos , Sensibilidad y Especificidad , Analgésicos Opioides/orina , Tiras ReactivasRESUMEN
Point-of-care testing (POCT) is becoming an increasingly popular way to perform laboratory tests closer to the patient. This option has several recognized advantages, such as accessibility, portability, speed, convenience, ease of use, ever-growing test panels, lower cumulative healthcare costs when used within appropriate clinical pathways, better patient empowerment and engagement, and reduction of certain pre-analytical errors, especially those related to specimen transportation. On the other hand, POCT also poses some limitations and risks, namely the risk of lower accuracy and reliability compared to traditional laboratory tests, quality control and connectivity issues, high dependence on operators (with varying levels of expertise or training), challenges related to patient data management, higher costs per individual test, regulatory and compliance issues such as the need for appropriate validation prior to clinical use (especially for rapid diagnostic tests; RDTs), as well as additional preanalytical sources of error that may remain undetected in this type of testing, which is usually based on whole blood samples (i.e., presence of interfering substances, clotting, hemolysis, etc.). There is no doubt that POCT is a breakthrough innovation in laboratory medicine, but the discussion on its appropriate use requires further debate and initiatives. This collective opinion paper, composed of abstracts of the lectures presented at the two-day expert meeting "Point-Of-Care-Testing: State of the Art and Perspective" (Venice, April 4-5, 2024), aims to provide a thoughtful overview of the state-of-the-art in POCT, its current applications, advantages and potential limitations, as well as some interesting reflections on the future perspectives of this particular field of laboratory medicine.
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Advances in technology have transformed healthcare and laboratory medicine. Biosensors have emerged as a promising technology in healthcare, providing a way to monitor human physiological parameters in a continuous, real-time, and non-intrusive manner and offering value and benefits in a wide range of applications. This position statement aims to present the current situation around biosensors, their perspectives and importantly the need to set the framework for their validation and safe use. The development of a qualification framework for biosensors should be conceptually adopted and extended to cover digitally measured biomarkers from biosensors for advancing healthcare and achieving more individualized patient management and better patient outcome.
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Técnicas Biosensibles , Técnicas Biosensibles/métodos , Humanos , Telemedicina , BioingenieríaRESUMEN
Comparing the performance of different continuous glucose monitoring (CGM) systems is challenging due to the lack of comprehensive guidelines for clinical study design. In particular, the absence of concise requirements for the distribution of comparator (reference) blood glucose (BG) concentrations and their rate of change (RoC) that are used to evaluate CGM performance, impairs comparability. For this article, several experts in the field of CGM performance testing have collaborated to propose characteristics of the distribution of comparator measurements that should be collected during CGM performance testing. Specifically, it is proposed that at least 7.5% of comparator BG concentrations are <70 mg/dL (3.9 mmol/L) and >300 mg/dL (16.7 mmol/L), respectively, and that at least 7.5% of BG-RoC combinations indicate fast BG changes with impending hypo- or hyperglycemia, respectively. These proposed characteristics of the comparator data can facilitate the harmonization of testing conditions across different studies and CGM systems and ensure that the most relevant scenarios representing real-life situations are established during performance testing. In addition, a study protocol and testing procedure for the manipulation of glucose levels are suggested that enable the collection of comparator data with these characteristics. This work is an important step toward establishing a future standard for the performance evaluation of CGM systems.
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Glucemia , Hiperglucemia , Humanos , Automonitorización de la Glucosa Sanguínea/métodos , Monitoreo Continuo de Glucosa , Hiperglucemia/diagnóstico , Hiperglucemia/prevención & controlRESUMEN
BACKGROUND: Accurate glucose monitoring is vitally important in neonatal intensive care units (NICUs) and clinicians use blood glucose monitors (BGM), such as the Inform II, for bedside glucose monitoring. Studies on BGM use in neonates have demonstrated good reliability; however, most studies only included healthy-term neonates. Therefore, the applicability of results to the preterm and/or ill neonate is limited. OBJECTIVES: In preterm and ill neonates, quantify differences in glucose concentrations between (1) capillary glucose (measured by BGM) and arterial glucose (measured by YSI 2300 Stat Plus) and (2) between aliquots from the same arterial blood sample, one measured by BGM versus one by YSI. DESIGN/METHODS: Forty neonates were included in the study. Using Inform II, we measured glucose concentrations on blood samples simultaneously collected from capillary circulation via heel puncture and from arterial circulation via an umbilical catheter. Plasma was then separated from the remainder of the arterial whole blood sample and a YSI 2300 Stat Plus measured plasma glucose concentration. RESULTS: The dominant majority of arterial BGM results met the Clinical and Laboratory Standard Institute (CLSI) and Food and Drug Administration (FDA) tolerance criteria. Greater discrepancy was observed with capillary BGM values with an average of 27.5% of results falling outside tolerance criteria. CONCLUSIONS: Blood glucose monitor testing provided reliable results from arterial blood. However, users should interpret hypoglycemic results obtained from capillary blood with caution.
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INTRODUCTION: Faster turnaround times can lead to rapid patient treatment. Implementing a point-of-care (POC) molecular COVID-19 test requires careful planning. In the POC setting, there are numerous operators and regular monitoring of their activities is key to the successful implementation of a POC molecular test. Test errors can arise from samples, operators, reagents, the testing system, and even from the environment. These sources of error should be considered when implementing a new test. AREAS COVERED: We outline the importance of establishing well-defined policies for staff to follow at the preanalytic, analytic and postanalytic phases of SARS-CoV-2 testing. As these factors are crucial for the accuracy and reliability of the test results. The key discussion points are from the CLSI EP23-Ed2 document on developing individualized quality control plans and medical literature search engines such as EMBASE, MEDLINE and MedlinePlus. EXPERT OPINION: The risk management principles applied when implementing nucleic acid POC tests can identify specific control processes to help mitigate common sources of error when conducting molecular testing at the POC.
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The use of different approaches for design and results presentation of studies for the clinical performance evaluation of continuous glucose monitoring (CGM) systems has long been recognized as a major challenge in comparing their results. However, a comprehensive characterization of the variability in study designs is currently unavailable. This article presents a scoping review of clinical CGM performance evaluations published between 2002 and 2022. Specifically, this review quantifies the prevalence of numerous options associated with various aspects of study design, including subject population, comparator (reference) method selection, testing procedures, and statistical accuracy evaluation. We found that there is a large variability in nearly all of those aspects and, in particular, in the characteristics of the comparator measurements. Furthermore, these characteristics as well as other crucial aspects of study design are often not reported in sufficient detail to allow an informed interpretation of study results. We therefore provide recommendations for reporting the general study design, CGM system use, comparator measurement approach, testing procedures, and data analysis/statistical performance evaluation. Additionally, this review aims to serve as a foundation for the development of a standardized CGM performance evaluation procedure, thereby supporting the goals and objectives of the Working Group on CGM established by the Scientific Division of the International Federation of Clinical Chemistry and Laboratory Medicine.
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Glucemia , Diabetes Mellitus Tipo 1 , Humanos , Automonitorización de la Glucosa Sanguínea/métodosRESUMEN
BACKGROUND: In this study, we evaluated the impact of hemoglobin (Hb) variants on the performance of the Abbott Alinity c and Bio-Rad Variant II Turbo 2.0 HPLC Hb A1c assays. METHODS: The analytical performance of the Abbott Alinity c Hb A1c (enzymatic) assay was compared to the Bio-Rad Variant II Turbo 2.0 HPLC method using leftover whole blood EDTA samples with and without the presence of a hemoglobin variant. Assay precision was determined from an analysis of controls. Bias was estimated from analysis of a set of 40 samples analyzed by a Tosoh G8 HPLC instrument at the University of Missouri Diabetes Diagnostic Laboratory, an NGSP Secondary Reference Laboratory. RESULTS: Between-day precision was excellent for both methods (<3%). Bias met NGSP criteria of ±5% to target value. Correlation between the Alinity and Bio-Rad methods was good for patient samples without a hemoglobinopathy (y = 1.028x - 0.38, standard error of the estimate (SEE) = 0.16, n = 36, mean bias = -0.22). A total of 700 hemoglobin variant samples were evaluated on the 2 methods. Of the hemoglobin variants, 640/700 gave results on both methods: hemoglobin (Hb) S trait (n = 452), C trait (n = 131), D trait (n = 23), E trait (n = 26), and a mixture of other hemoglobinopathies (n = 8) including beta thalassemia, high hemoglobin F, transfused Hb SC, transfused Hb SD, and transfused Hb SS, or unknown variant. There was good agreement for the 640 Hb variants between the methods with a range of mean differences of -0.10 to +0.06 depending on the variant, but more variability (SEE 0.25 to 0.39). Sixty samples did not have paired results. CONCLUSIONS: To our knowledge, this study was the largest investigation of the effect of hemoglobinopathies on the Abbott Alinity c Hb A1c assay. Analytical performance varied depending on the specific hemoglobin variant trait when compared to the Bio-Rad Variant II Turbo 2.0 HPLC method.
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Hemoglobinopatías , Hemoglobinas , Humanos , Hemoglobina Glucada , Cromatografía Líquida de Alta Presión/métodos , Hemoglobinas/análisis , Hemoglobinopatías/diagnóstico , Pruebas de EnzimasRESUMEN
As testing for infectious diseases moves from manual, biological testing such as complement fixation to high throughput automated autoanalyzer, the methods for controlling these assays have also changed to reflect those used in clinical chemistry. However, there are many differences between infectious disease serology and clinical chemistry testing, and these differences have not been considered when applying traditional quality control methods to serology. Infectious disease serology, which is highly regulated, detects antibodies of varying classes and to multiple and different antigens that change according to the organisms' genotype/serotype and stage of disease. Although the tests report a numerical value (usually signal to cut-off), they are not measuring an amount of antibodies, but the intensity of binding within the test system. All serology assays experience lot-to-lot variation, making the use of quality control methods used in clinical chemistry inappropriate. In many jurisdictions, the use of the manufacturer-provided kit controls is mandatory to validate the test run. Use of third-party controls, which are highly recommended by ISO 15189 and the World Health Organization, must be manufactured in a manner whereby they have minimal lot-to-lot variation and at a level where they detect exceptional variation. This paper outlines the differences between clinical chemistry and infectious disease serology and offers a range of recommendations when addressing the quality control of infectious disease serology.
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Enfermedades Transmisibles , Humanos , Enfermedades Transmisibles/diagnóstico , Control de Calidad , Pruebas InmunológicasRESUMEN
BACKGROUND: The AACC Academy revised the reproductive testing section of the Laboratory Medicine Practice Guidelines: Evidence-Based Practice for Point-of-Care Testing (POCT) published in 2007. METHODS: A panel of Academy members with expertise in POCT and laboratory medicine was formed to develop guidance for the use of POCT in reproductive health, specifically ovulation, pregnancy, premature rupture of membranes (PROM), and high-risk deliveries. The committee was supplemented with clinicians having Emergency Medicine and Obstetrics/Gynecology training. RESULTS: Key recommendations include the following. First, urine luteinizing hormone (LH) tests are accurate and reliable predictors of ovulation. Studies have shown that the use of ovulation predicting kits may improve the likelihood of conception among healthy fertile women seeking pregnancy. Urinary LH point-of-care testing demonstrates a comparable performance among other ovulation monitoring methods for timing intrauterine insemination and confirming sufficient ovulation induction before oocyte retrieval during in vitro fertilization. Second, pregnancy POCT should be considered in clinical situations where rapid diagnosis of pregnancy is needed for treatment decisions, and laboratory analysis cannot meet the required turnaround time. Third, PROM testing using commercial kits alone is not recommended without clinical signs of rupture of membranes, such as leakage of amniotic fluid from the cervical opening. Finally, fetal scalp lactate is used more than fetal scalp pH for fetal acidosis due to higher success rate and low volume of sample required. CONCLUSIONS: This revision of the AACC Academy POCT guidelines provides recommendations for best practice use of POCT in fertility and reproduction.
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Fertilidad , Reproducción , Femenino , Humanos , Pruebas en el Punto de Atención , EmbarazoRESUMEN
This article is the work product of the Continuous Ketone Monitoring Consensus Panel, which was organized by Diabetes Technology Society and met virtually on April 20, 2021. The panel consisted of 20 US-based experts in the use of diabetes technology, representing adult endocrinology, pediatric endocrinology, advanced practice nursing, diabetes care and education, clinical chemistry, and bioengineering. The panelists were from universities, hospitals, freestanding research institutes, government, and private practice. Panelists reviewed the medical literature pertaining to ten topics: (1) physiology of ketone production, (2) measurement of ketones, (3) performance of the first continuous ketone monitor (CKM) reported to be used in human trials, (4) demographics and epidemiology of diabetic ketoacidosis (DKA), (5) atypical hyperketonemia, (6) prevention of DKA, (7) non-DKA states of fasting ketonemia and ketonuria, (8) potential integration of CKMs with pumps and automated insulin delivery systems to prevent DKA, (9) clinical trials of CKMs, and (10) the future of CKMs. The panelists summarized the medical literature for each of the ten topics in this report. They also developed 30 conclusions (amounting to three conclusions for each topic) about CKMs and voted unanimously to adopt the 30 conclusions. This report is intended to support the development of safe and effective continuous ketone monitoring and to apply this technology in ways that will benefit people with diabetes.
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Cetoacidosis Diabética , Cetosis , Adulto , Niño , Consenso , Cetoacidosis Diabética/prevención & control , Humanos , Cetonas , Monitoreo FisiológicoRESUMEN
BACKGROUND: Point-of-Care Testing (POCT) is clinical laboratory testing conducted close to the site of patient care. POCT provides rapid turnaround of test results with the potential for fast clinical action that can improve patient outcomes compared to laboratory testing. METHODS: Review the advantages of POCT and discuss the factors that are driving the expansion of POCT in modern healthcare. RESULTS: Portability, ease-of-use, and minimal training are some of the advantages of POCT. The ability to obtain a fast test result and the convenience of testing close to the patient are increasing the demand for POCT. Healthcare is finding new opportunities for growth in the community and POCT is facilitating this growth. CONCLUSIONS: This article will review the advantages of POCT and how POCT is complimenting patient care in a variety of settings.
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BACKGROUND: Quality management of point-of-care (POC) blood gas testing focuses on verifying instrument accuracy and precision, in addition to performing daily quality control (QC) checks every 8 h and with each patient test (unless internal calibration is verified every 30 min). At the POC, a risk-based approach is suitable to address both systemic and transient sample-specific errors that may negatively impact patient care. METHODS: We evaluated the performance of the GEM® Premier™ 5000 with next generation Intelligent Quality Management 2 (iQM®2) (Instrumentation Laboratory, Bedford, MA), from the analysis of approximately 84,000 patient samples across 4 sites. Continuous iQM2 was compared to intermittent liquid QC, either manual or automated, at 2 sites. Analysis of error flags for patient samples and statistical characteristics of QC processes, including method sigma and average detection time (ADT) for an error, were examined. RESULTS: ADT was approximately 2 min with iQM2 and varied from hours to days with intermittent QC. iQM2 Process Control Solutions (PCS) precision was similar or better (>6 sigma for all analytes) than manual (sigma 3.0 for pO2) or automated internal QC (sigma 1.3 for tHb and sigma 3.3 for pO2). In addition, iQM2 detected errors in â¼1.4% of samples, providing an additional safeguard against reporting erroneous results. CONCLUSIONS: The findings in this study demonstrate excellent performance of the GEM Premier 5000 with iQM2 including >6 sigma precision for all analytes and faster error detection times. These benefits address risk in different phases of testing that are not easily detected by intermittent performance of liquid QC (manual or automated).
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Electrólitos , Oximetría , Calibración , Humanos , Laboratorios , Control de CalidadRESUMEN
BACKGROUND: Sigma metric calculations provide laboratories an objective means to assess analytical method performance. Methods with higher sigma values are desirable because they are more reliable and may use less frequent quality control in order to maintain optimal performance. Sigma metrics can also serve as a tool when comparing method performance across assay and manufacturer platforms. METHODS: Sigma values were calculated for 28 common chemistry and 24 immunoassay assays across 3 academic medical centers. Method imprecision and percent bias relative to peer group means was tabulated from Bio-Rad quality control (QC) data. Sigma values were calculated for each method using allowable total error (TEa) from either the CLIA evaluation limits or desirable biological variation. Average sigma values were generated for each site and graded as optimal: >6 sigma; good: 5-6 sigma; marginal: 3-5 sigma; or poor: <3 sigma. Analysis of NIST SRM1950 standards for a subset of analytes allowed an estimation of absolute bias. RESULTS: Clinical chemistry assays displayed similar method performance across all 3 study sites. Immunoassays showed significant differences between manufacturers, and a majority of assays failed to meet an optimal level of performance. Different TEa values produced different sigma metrics with more stringent TEa limits based on biological variation, resulting in poorer performance estimates than the wider CLIA limits. Analysis of NIST standards revealed similar performance. CONCLUSIONS: Sigma metrics are comparable for chemistry but not immunoassay platforms. The selection of total allowable error goals led to differences in sigma metrics.
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Centros Médicos Académicos , Gestión de la Calidad Total , Humanos , Inmunoensayo , Control de Calidad , Estándares de ReferenciaRESUMEN
BACKGROUND: A survey of IFCC members was conducted to determine current and future perspectives on digital innovations within laboratory medicine and healthcare sectors. METHODS: Questions focused on the relevance of digital diagnostic solutions, implementation and barriers to adopting digital technologies, and supplier roles in supporting innovation. Digital diagnostic market segments were defined by solution recipient (laboratory, clinician, patient/consumer, payor) and proximity to core laboratory operations. RESULTS: Digital solutions were of active interest for >90% of respondents. Although solutions to improve core operations were ranked as the most relevant currently, a future shift to technologies beyond core laboratory expertise is expected. A key area of potential differentiation for laboratory customers was clinical decision support. Currently, laboratories collaborate strongly with suppliers of laboratory integration software and information systems, with high expectations for future collaboration in clinical decision support, disease self-management, and population health management. Asia Pacific countries attributed greater importance to adopting digital solutions than those in other regions. Financial burden was the most commonly cited challenge in implementing digital solutions. CONCLUSIONS: Specialists in laboratory medicine are proactively approaching digital innovations and transformation, and there is high enthusiasm and expectation for further collaboration with suppliers and healthcare professionals beyond current core laboratory expertise.
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Sistemas de Apoyo a Decisiones Clínicas , Telemedicina , Química Clínica , Humanos , Laboratorios , Encuestas y CuestionariosRESUMEN
BACKGROUND: Our purpose was to evaluate the performance of the ACCU-CHEK® Inform II blood glucose monitoring system (Roche Diagnostics GmbH) compared with the perchloric acid hexokinase (PCA-HK) comparator method on the cobas® 6000 analyzer (Roche Diagnostics International Ltd) in critically ill patients. METHODS: Overall, 476 arterial (376 pediatric/adult, 100 neonate), 375 venous, and 100 neonatal heel-stick whole-blood samples were collected and evaluated from critical care settings at 10 US hospitals, including the emergency department, medical and surgical intensive care units (ICUs), and neonatal and pediatric ICUs. The ACCU-CHEK Inform II system was evaluated at 2 cutoff boundaries: boundary 1 was ≥95% of results within ±12 mg/dL of the reference (samples with blood glucose <75 mg/dL) or ±12% of the reference (glucose ≥75 mg/dL), and boundary 2 was ≥98% of results within ±15 mg/dL or ±15% of the reference. Clinical performance was assessed by evaluating sample data using Parkes error grid, Monte Carlo simulation, and sensitivity and specificity analyses to estimate clinical accuracy and implications for insulin dosing when using the ACCU-CHEK Inform II system. RESULTS: Proportions of results within evaluation boundaries 1 and 2, respectively, were 96% and 98% for venous samples, 94% and 97% for pediatric and adult arterial samples, 84% and 98% for neonatal arterial samples, and 96% and 100% for neonatal heel-stick samples. Clinical evaluation demonstrated high specificity and sensitivity, with low risk of potential insulin-dosing errors. CONCLUSIONS: The ACCU-CHEK Inform II system demonstrated clinically acceptable performance against the PCA-HK reference method for blood glucose monitoring in a diverse population of critically ill patients in US care settings.