Quality Control Program Research Articles

B-109 Six Sigma Analysis for Enhancing Biochemistry Internal Quality Control in a Private Laboratory in India

Abstract Background This abstract outlines a comprehensive study on the application of Six Sigma methodologies to optimize internal quality control processes in a private biochemistry laboratory in India. Data collection was performed using Bio-Rad Assayed Chemistry Control on the Roche cobas 6000 instrument, facilitated by Bio-Rad Unity software. The study adheres to Clinical Laboratory Improvement Amendments (CLIA) 2024 guidelines, specifically focusing on Total Error (TEa). Methods The analytical performances of Cobas c501 insturment as analyse by running biochemical tests (urea, creatinine, uric acid, total bilirubin, AST, Amylase, Lipase, CK, LD, ALT, ALP, LDH, HDL-C, Ca2+, cholesterol, TG, HDL LDL, total protein, albumin, Na+, K+, and Cl−) and glucose on Cobas 400 were evaluated. Biases and CV were obtained from internal quality control programs using biorad unity software. The performance of each instrument was assessed using the σ scale; the benchmark performance was <3 σ (improvement needed); “world-class” quality was six sigma. Results Analytes such as “Alk PO4,” “ALT,” “Amylase,” “Bilirubin,” “CK,” “GGT,” “LD,” “Phosphorus,” “HDL,” “LDL Cholesterol,” “Triglycerides,” and “Uric acid” exhibited impressive sigma scores exceeding 6. Meanwhile, analytes including “Calcium,” “Total Cholesterol,” “Potassium,” “Total Protein,” “Urea,” and “Glucose” achieved sigma scores between 4 and 6, demonstrating noteworthy performance within acceptable bounds. Conclusions This study contributes valuable insights to laboratory management, specifically in the context of biochemistry testing in private Indian laboratories. The adoption of Six Sigma principles, coupled with adherence to CLIA 2024 guidelines and the utilization of advanced instrumentation and software, ensures compliance with regulatory requirements and fosters a culture of continuous improvement. This positions the laboratory to deliver high-quality and reliable results in the dynamic landscape of healthcare diagnostics.

AAPM Task Group Report 299: Quality control in multi-energy computed tomography.

Multi-energy computed tomography (MECT) offers the opportunity for advanced visualization, detection, and quantification of select elements (e.g., iodine) or materials (e.g., fat) beyond the capability of standard single-energy computed tomography (CT). However, the use of MECT requires careful consideration as substantially different hardware and software approaches have been used by manufacturers, including different sets of user-selected or hidden parameters that affect the performance and radiation dose of MECT. Another important consideration when designing MECT protocols is appreciation of the specific tasks being performed; for instance, differentiating between two different materials or quantifying a specific element. For a given task, it is imperative to consider both the radiation dose and task-specific image quality requirements. Development of a quality control (QC) program is essential to ensure the accuracy and reproducibility of these MECT applications. Although standard QC procedures have been well established for conventional single-energy CT, the substantial differences between single-energy CT and MECT in terms of system implementations, imaging protocols, and clinical tasks warrant QC tests specific to MECT. This task group was therefore charged with developing a systematic QC program designed to meet the needs of MECT applications. In this report, we review the various MECT approaches that are commercially available, including information about hardware implementation, MECT image types, image reconstruction, and postprocessing techniques that are unique to MECT. We address the requirements for MECT phantoms, review representative commercial MECT phantoms, and offer guidance regarding homemade MECT phantoms. We discuss the development of MECT protocols, which must be designed carefully with proper consideration of MECT technology, imaging task, and radiation dose. We then outline specific recommended QC tests in terms of general image quality, radiation dose, differentiation and quantification tasks, and diagnostic and therapeutic applications.

Development and validation of a deep learning model for detecting signs of tuberculosis on chest radiographs among US-bound immigrants and refugees.

Immigrants and refugees seeking admission to the United States must first undergo an overseas medical exam, overseen by the US Centers for Disease Control and Prevention (CDC), during which all persons ≥15 years old receive a chest x-ray to look for signs of tuberculosis. Although individual screening sites often implement quality control (QC) programs to ensure radiographs are interpreted correctly, the CDC does not currently have a method for conducting similar QC reviews at scale. We obtained digitized chest radiographs collected as part of the overseas immigration medical exam. Using radiographs from applicants 15 years old and older, we trained deep learning models to perform three tasks: identifying abnormal radiographs; identifying abnormal radiographs suggestive of tuberculosis; and identifying the specific findings (e.g., cavities or infiltrates) in abnormal radiographs. We then evaluated the models on both internal and external testing datasets, focusing on two classes of performance metrics: individual-level metrics, like sensitivity and specificity, and sample-level metrics, like accuracy in predicting the prevalence of abnormal radiographs. A total of 152,012 images (one image per applicant; mean applicant age 39 years) were used for model training. On our internal test dataset, our models performed well both in identifying abnormalities suggestive of TB (area under the curve [AUC] of 0.97; 95% confidence interval [CI]: 0.95, 0.98) and in estimating sample-level counts of the same (-2% absolute percentage error; 95% CIC: -8%, 6%). On the external test datasets, our models performed similarly well in identifying both generic abnormalities (AUCs ranging from 0.89 to 0.92) and those suggestive of TB (AUCs from 0.94 to 0.99). This performance was consistent across metrics, including those based on thresholded class predictions, like sensitivity, specificity, and F1 score. Strong performance relative to high-quality radiological reference standards across a variety of datasets suggests our models may make reliable tools for supporting chest radiography QC activities at CDC.

Implementing a Phase II Quality Control Protocol for a High Precision 137Cs Dosimetry Calibration Irradiator.

In medical physics, rigorous quality assurance and quality control protocols are vital for precise dose delivery applications. In many health physics applications, the allowable uncertainty for various processes is often greater than that of medical physics due to looser safety ties. This results in less demand for quality control and uncertainty analyses, since these may not be needed. However, certain applications can benefit from a comprehensive quality control program, as it may yield important insights, such as air kerma monitoring in dosimetry calibrations for environmental and low-dose applications. By implementing a thorough quality control program tailored to specific contexts and needs, uncertainties associated with dose measurements can be quantified with greater accuracy and reliability. This proactive approach not only ensures the integrity of data collected but also enhances understanding of the measured doses. For these reasons, a comprehensive quality control initiative was implemented following documented failures in a 137Cs dosimetry calibration irradiator. This involved systematic charge collection using NIST-traceable ion chambers to observe long-term changes. A Phase I quality control protocol was previously implemented, which employed Shewhart control charts and Nelson's rules to analyze various datasets subgrouped under different conditions. This study addresses the development of a Phase II protocol, which focuses more on uncertainty quantification of systematic errors and irradiator changes, and air kerma precision for dosimetry calibrations. A designed experiment was performed to identify how much systematic errors influence the air kerma. Emphasis was placed on stricter quality assurance protocols, continuous data collection, and additional control charts to monitor short-term changes, such as exponentially weighted moving average control charts. A pre-irradiation control process was implemented to verify that the total air kerma met the measurement quality objective and to show how various uncertainties were applied before calibration. This study indicates how uncertainty is applied given observed air kerma measurements from the irradiator. Ongoing efforts aim to streamline the quality control procedure, ensure consistent data collection, and assess its impact on dosimetry applications.

Deficiency in the mitophagy mediator Parkin accelerates murine skin allograft rejection

Alterations in mitochondrial function and associated quality control programs, including mitochondrial-specific autophagy, termed mitophagy, are gaining increasing recognition in the context of disease. However, the role of mitophagy in organ transplant rejection remains poorly understood. Using mice deficient in Parkin, a ubiquitin ligase that tags damaged or dysfunctional mitochondria for autophagic clearance, we assessed the impact of Parkin-dependent mitophagy on skin-graft rejection. We observed accelerated graft loss in Parkin-deficient mice across multiple skin graft models. Immune cell distributions posttransplant were largely unperturbed compared to wild-type; however, the CD8+ T cells of Parkin-deficient mice expressed more T-bet, IFNγ, and Ki67, indicating greater priming toward effector function. This was accompanied by increased circulating levels of IL-12p70 in Parkin-deficient mice. Using a mixed leukocyte reaction, we demonstrated that naïve Parkin-deficient CD4+ and CD8+ T cells exhibit enhanced activation marker expression and proliferative responses to alloantigen, which were attenuated with administration of a pharmacological mitophagy inducer (p62-mediated mitophagy inducer), known to increase mitophagy in the absence of a functional PINK1-Parkin pathway. These findings indicate a role for Parkin-dependent mitophagy in curtailing skin-graft rejection.

Quality control of the stereotactic radiosurgery procedure with the alanine-EPR dosimetry

The SRS Technique is a procedure that uses ionizing radiation usually in a single dose or in a maximum number of five fractions for the treatment of intracranial lesions. Multiple brain metastases single-isocenter stereotactic radiosurgery (SRS) treatment is increasingly employed in radiotherapy services. In this treatment is required that the prescription dose be restricted to the lesion only and have a pronounced dose decay in the adjacent healthy tissue. An extensive quality control program must be employed to ensure the quality of the entire treatment procedure. The purpose of this study was to investigate the use of alanine-EPR dosimeters as a dosimetric tool for quality control of the stereotactic radiosurgery procedure using the Volume Modulated Arc Technique (VMAT). The results showed that the alanine-EPR response is linear with the radiation dose in the range from 2 to 100 Gy, with a low dose rate and energy dependencies. The results of the doses measured with alanine in relation to the planned value for the four lesions were concordant, with differences smaller than 1.2%. The experiment enabled a comprehensive assessment of the entire SRS procedure, encompassing both the treatment planning and irradiation phases. Consequently, both mechanical and dosimetric parameters can be evaluated concurrently, allowing for a comprehensive assessment of the total inaccuracy of the procedure.

Analytical performance of publicly dispensed glucometers in primary health care in a southern Brazilian city

AimsThis study aimed to assess the use of glucometers by patients and the analytical performance of glucometers provided by the primary care services. MethodsThe analytical performance of 48 glucometers Accu-Chek® Active, was assessed through quintuplicate analyses of one Roche and one PNCQ (National Quality Control Program) control sample at different concentrations; 31 were also evaluated by a single proficiency testing sample. The evaluation metrics included imprecision, bias, and total error and were measured according to quality specifications based on biological variation (QSBV). Glucometer users answered a questionnaire regarding their experience. ResultsAmong the 48 glucometers evaluated with internal control samples, 17 met precision criteria at both control levels according to QSBV, while 24 met the criteria at only one control level. Of the 31 glucometers further evaluated through proficiency test, 11 met accuracy criteria according to QSBV, and only one device showed an unacceptable result. Out of these 31, only 15 demonstrated a total error within the acceptable maximum limits based on QSBV. ConclusionsOverall, our findings showed that patients had a good understanding of glucometer usage and suggested that some glucometers should be replaced, as they sometimes failed to meet even the manufacturer’s acceptable variation limits, and/or did not meet QSBV.

Preclinical SPECT and PET: Joint EANM and ESMI procedure guideline for implementing an efficient quality control programme.

The aim of this guideline is to provide recommendations for the implementation of an effective and efficient quality control (QC) programme for SPECT and PET systems in a preclinical imaging lab. These recommendations aim to strengthen the translational power of preclinical imaging results obtained using preclinical SPECT and PET. As for clinical imaging, reliability, reproducibility, and repeatability are essential when groups of animals are used in a longitudinal imaging experiment. The larger the variability of the imaging endpoint, the more animals are needed to be able to observe statistically significant differences between groups. Therefore, preclinical imaging requires quality control procedures to maintain reliability, reproducibility, and repeatability of imaging procedures, and to ensure the accuracy and precision of SPECT and PET quantification. While the Physics Committee of the European Association of Nuclear Medicine (EANM) has already published excellent procedure guidelines for Routine Quality Control Recommendations for Nuclear Medicine Instrumentationthat also includes procedures for small animal PET systems, and important steps have already been made concerning preclinical quality control aspects, this new guideline provides a review and update of these previous guidelines such that guidelines are also adapted to new technological developments.

Effect of quality control program on surgical management in advanced ovarian cancer.

We investigated the effect of our quality control (QC) program on the management strategy, completeness of the surgery, and clinical outcomes in advanced ovarian cancer. A retrospective review of medical records from January 2005 to December 2019 identified 129 patients with advanced ovarian cancer. Cases were categorized into group 1 (2005-2013) and group 2 (2014-2019) before and after implementation of the QC program. Comparisons included clinicopathological variables, operative details, recurrence and survival outcomes. In Group 2 (n=44), after QC program implementation, primary debulking surgery (PDS) decreased (87.1% vs. 63.6%) and interval debulking surgery (IDS) increased (12.9% vs. 36.4%), indicating a shift in surgical strategy. Optimal resection rates improved significantly for PDS in group 2 (50.0% to 75.0%, p=0.007) and remained high for IDS in both groups (81.8% vs. 81.3%, p>0.999). Post-QC, advanced debulking procedures and co-operation with other departments increased in the IDS (p<0.05). Intra/post-operative complication rates were statistically comparable (p>0.05), whereas postoperative hospital stay was significantly shorter in group 2 (17 days vs. 22 days, p=0.001). Median recurrence-free survival increased after QC, although not statistically significant (19.18 months vs. 25.38 months, p=0.855). With QC program, treatment strategies and clinical outcomes were significantly improved in advanced ovarian cancer. Systematic QC monitoring program should be considered as routine surveillance for better surgical outcomes.

Evaluation of structural problems in the application of strict criteria for sperm morphology assessment.

The WHO manual for basic semen analysis and ISO 23162 describe sperm morphology assessment as a standard part of semen analysis. Older studies showed a correlation between morphology results and (artificial) conception. In more recent studies this relationship was less apparent and there is more emphasis on sperm morphology as a marker for healthy spermatogenesis (and general male health). Meantime, many laboratories ceased morphology assessment, probably due to unfamiliarity with this paradigmatic shift and to technical difficulties in the assessment, like the interpretation of morphological criteria. The aim of this study was to identify morphological criteria with high variability in results in the Dutch External Quality Control (EQC) program. Over the period 2015-2020, a total of 72 photos of sperm cells along with dichotomous propositions based on 14 criteria as defined in WHO5 (2010) were distributed in the Dutch EQC program for semen analysis. The EQC results were evaluated for variability per criterion and for trends in time. Between 2015 and 2020, 40 to 60 laboratories assessed the photos. Criteria with low variability between participants were related to acrosomal vacuoles, excessive residual cytoplasm, and tail metrics. In contrast, head ovality, regularity of head and midpiece contours, and alignment of the major axis of the midpiece and head led to the highest variability in outcomes. In general, there was a slightly positive trend (lower variability) in time, except for the criteria with the highest variability (stable or declining trend). This study indicates that there are (high) variabilities in the interpretation of the morphological criteria, leading to inconsistent outcomes of morphology assessment. The results are discussed from the perspective of imperfections in definitions and examples of the criteria as given in the WHO manuals.

A survey of gamma camera and SPECT/CT quality control programs across a sample of public hospitals in Australia.

Performance testing of gamma cameras and single photon computed tomography/computed tomography (SPECT/CT) systems is not subject to regulatory requirements across states and territories in Australia. Internationally recognised testing standards from organisations such as the National Electrical Manufacturers Association (NEMA) describe methodologies for recommended tests. However, variations exist in suggested quality control (QC) schedules from professional bodies such as the Australia and New Zealand Society of Nuclear Medicine (ANZSNM). In this study, a survey was conducted to benchmark current QC programs across a selected sample of eight standalone and networked Australian public hospitals. Vendor-specific flood-field uniformity (intrinsic or extrinsic/system) verification without photomultiplier (PMT) tuning and CT QC were performed at all sites. Weekly and monthly PMT tuning followed by intrinsic flood-field verifications were performed at most sites. At least half of the sites performed monthly centre of rotation (COR) offset verifications. SPECT/CT alignment calibrations and verifications were undertaken by service engineers at all sites, and periodic verifications were performed by local staff at varying frequencies. Variations were observed for other periodic QC tests such as spatial resolution and planar sensitivity. Similarly, variations were observed for tests specific to whole-body systems and SPECT systems. Most sites checked daily and periodic QC results against pass/fail criteria set by vendors. Additional analyses of the QC results, including trend analysis and periodic reviews, were not common practice. The lack of regulatory requirements is likely to have led to variations in QC tests that are generally either harder to perform or are more labour intensive.

A novel organoselenium-based Schiff base for selective separation of copper and zinc from food samples using ultrasonic-assisted solidified floating organic drop microextraction strategy

Herein, we document the development of a novel organoselenium-based Schiff base, 2-((4-((2-hydroxy-4-nitrobenzylidene)amino)phenyl)selanyl)-N-phenylacetamide (HOASe), to selectively separate zinc and copper from food samples. To the best of our knowledge, OSe compound has never been used in microextraction procedures before, until today. HOASe was synthesized from aniline by a simple four-step procedure. The structure of HOASe was elucidated by various spectroscopic techniques (e.g., IR, MS, 1H- and 13C NMR). After that, HOASe was used to extract Cu2+ and Zn2+ by ultrasonic-assisted dispersive liquid-liquid microextraction based on the solidification of floating organic drop (UA-DLLME-SFOD) combined with flame atomic absorption spectrometry. Important experimental parameters including amount of the extraction solvent, initial pH, amount of HOASe, ultrasonication time, centrifugation, and salt addition, were studied and optimized to offer quantitative separation of the analytes. The detection limits and the linear ranges for Cu2+ and Zn2+ were 1.9, 8.0 – 400.0, and 2.4, 6 – 150 μg L-1, respectively. The method's greenness and applicability were assessed using the Analytical GREEnness metric methodology and the Blue Applicability Grade Index, respectively. Finaly, this approach was used for quantification of Cu2+ and Zn2+ in food samples and, therefore, can be further developed for food safety and quality control programs.

A comprehensive assessment of quality management methods in the SMESH study

BackgroundThis paper aims to instigate discussion and publication of methodologies applied to enhance quality management through comprehensive scientific reports. It provides a detailed description of the design, implementation, and results of the quality control program employed in the SMESH study.MethodsCross-sectional, multicenter, national study designed to assess the prevalence of human papillomavirus in sex workers and in men who have sex with men (MSM). Respondent-driven sampling recruitment was used. An online system was developed for the study and checkpoints were defined for data entry. The system checked the quality of biological samples and performed a retest with part of the sample.ResultsA total of 1.598 participants (442 sex workers and 1.156 MSM) were included. Fifty-four health professionals were trained for face-to-face data collection. The retest showed Kappa values ranging between 0.3030 and 0.7663.ConclusionThe retest data were mostly classified as indicating a strong association. The data generated by the checkpoints showed the successful implementation of the quality control program.

OILVEQ: an Italian external quality control scheme for cannabinoids analysis in galenic preparations of cannabis oil.

Italy legalized cannabis oil for specific medical conditions (neuropathic pain, refractory epilepsy and other established pathologies) in 2015, but mandates titration of principal cannabinoids before marketing each batch using iphenated techniques coupled with mass spectrometry. To assess reliability of laboratories from the Italian National Health Service in charge of titrating the batches, the Italian National Institute of Health set up an quality control program on determination of Δ9-tetrahydrocannabinol l (THC), cannabidiol (CBD), Δ9-tetrahydrocannabinolic acid A (THCA-A) and cannabidiolic acid (CBDA) in cannabis oil preparations. Two rounds of exercises have been carried out since 2019, involving sixteen Italian laboratories. Five different cannabis oil samples (19-1A and 19-1B for the first round and 22-1A, 22-1B and 22-1C for the second one were prepared and 1 mL amount of each sample was sent to the laboratories. The quantitative performance of each laboratory was assessed calculating the Z-score value, a statistical measurement for value's relationship to the mean of a group of values. In the first round, eight out of fourteen laboratories employed an LC-MS while the remaining six used GC-MS. Differently, in the second round, six out of eleven laboratories employed a GC-MS while the remaining five used LC-MS. In the first round, only 28.6 % laboratories achieved an acceptable performance (Z-score±2), and all of them used LC-MS as analytical method. In the second round, none of the laboratories achieved an acceptable performance. Satisfactory results, based on Z-scores, were generally low (0.0-75.0 %), with only one exception of 100 % for THCA-A determination in sample 22-1B. In the second round, three false negatives (two THC and one CBD by GC-MS determination) were reported while no false positives were described in the blank sample. The two rounds yielded a mean ERR% of 42 % approximately and a mean CV% around 70 % in GC-MS determination. When applying LC-MS determination, the two rounds yielded a mean ERR% of 36 % approximately and a mean CV% around 33 %. The obtained results underline the need for a clear and consistent protocol to be adopted by all laboratories intending to include the titration of oily cannabis-based products into their routinely analytical techniques. This emphasis on methodology standardization and participation to quality control schemes is essential for ensuring reliable and accurate measurements, ultimately enhancing the overall effectiveness and reliability of medical cannabis treatments.

AAPM Task Group Report 261: Comprehensive quality control methodology and management of dental and maxillofacial cone beam computed tomography (CBCT) systems.

Cone-beam computed tomography (CBCT) systems specifically designed and manufactured for dental, maxillofacial imaging (MFI) and otolaryngology (OLR) applications have been commercially available in the United States since 2001 and have been in widespread clinical use since. Until recently, there has been a lack of professional guidance available for medical physicists about how to assess and evaluate the performance of these systems and about the establishment and management of quality control (QC) programs. The owners and users of dental CBCT systems may have only a rudimentary understanding of this technology, including how it differs from conventional multidetector CT (MDCT) in terms of acceptable radiation safety practices. Dental CBCT systems differ from MDCT in several ways and these differences are described. This report provides guidance to medical physicists and serves as a basis for stakeholders to make informed decisions regarding how to manage and develop a QC program for dental CBCT systems. It is important that a medical physicist with experience in dental CBCT serves as a resource on this technology and the associated radiation protection best practices. The medical physicist should be involved at the pre-installation stage to ensure that a CBCT room configuration allows for a safe and efficient workflow and that structural shielding, if needed, is designed into the architectural plans. Acceptance testing of new installations should include assessment of mechanical alignment of patient positioning lasers and x-ray beam collimation and benchmarking of essential image quality performance parameters such as image uniformity, noise, contrast-to-noise ratio (CNR), spatial resolution, and artifacts. Several approaches for quantifying radiation output from these systems are described, including simply measuring the incident air-kerma (Kair) at the entrance surface of the image receptor. These measurements are to be repeated at least annually as part of routine QC by the medical physicist. QC programs for dental CBCT, at least in the United States, are often driven by state regulations, accreditation program requirements, or manufacturer recommendations.

Analysis of Influencing Factors on Participation Compliance, Slide Preparations Quality and Microscopic Reading Quality of Acid-Resistant Bacteria Slides at Ciamis Regency

Background &amp; Objective: To find out the factors that influence participation compliance, slide preparations quality and microscopic reading quality in the External Quality Control program of Microscopic Cross Tests Acid Resistant Bacteria in Ciamis Regency in 2022-2023 Method: The research design is cross-sectional, population and total sampling of 27 respondents. Data analysis is Chi-Square with Fisher's Exact Test Result: Research data shows that the sig-p value of the period of employment variable for participation is 0.057, for the quality of slide preparations per quarter 0.695, 0.447, 0.550, 0.305, and the microscopic reading quality 0.036. The sig-p value of the training variable on participation is 0.226, on the quality of slide preparations per quarter 0.043, 0.388, 0.212, 0.219, and the microscopic reading quality 0.298. The sig-p value of the workload variable for participation is 0.204, for the quality of slide preparations per quarter 0.502, 0.091, 0.332, 0.502, and for the microscopic reading quality 0.050. The sig-p value of the microscope condition variable for participation is 0.005, for the quality of slide preparations per quarter 0.063, 0.106, 0.149, 0.323, and for the microscopic reading quality 0.036. The sig-p value of the incentive variable for participation is 0.001, for the quality of slide preparations per quarter 0.528, 0.302, 0.586, 0.189, for the microscopic reading quality of 0.013 Conclusion: there is a relationship between microscope conditions and incentive on participation compliance, there is a relationship between training on the slide preparations quality in the 4th quarter of 2022, there is a relationship between period of employment, workload, microscope conditions and incentive on microscopic reading quality

International circumpolar surveillance: update on the interlaboratory quality control program for Streptococcus pneumoniae, 2009 to 2020.

Arctic populations experience several social and physical challenges that lead to the increased spread and incidence of invasive diseases. The International Circumpolar Surveillance (ICS) program was developed to monitor five invasive bacterial diseases in Arctic countries and territories. Each ICS organism has a corresponding interlaboratory quality control (QC) program for laboratory-based typing, to ensure the technical precision and accuracy of reference testing services for these regions, and identify and correct potential problems. Here, we describe the results of the ICS Streptococcus pneumoniae QC program, from 2009 to 2020. Excellent overall concordance was achieved for serotype and antimicrobial susceptibility testing results across six laboratories. Ongoing participation in these QC programs ensures the continuation of quality surveillance systems within Arctic populations that experience health disparities.

Practical applications of quality assurance and quality control in mineral exploration, resource estimation and mining programmes: a review of recommended international practices

Independent quality assurance and quality control (QA/QC) programmes are required by reporting codes for publicly listed companies and are necessary to optimize data quality at all stages of the sampling, preparation and analytical processes involved in mineral exploration, resource estimation and mining grade control. QA/QC programmes should be adjusted over time to meet changing requirements in data quality at different stages of mineral resource development and exploitation. Certified reference materials are used to monitor accuracy and bias at the project laboratory relative to consensus values for the material from round-robin certification analyses. They are also used to monitor drift over time within an individual laboratory and to identify significant failures in QC at the analytical batch level caused by abrupt changes in concentration related to re-calibration of instruments or procedural changes at the laboratory. Duplicate analyses of sample material are generated at key stages of sampling and preparation to estimate the precision of data generated at each stage. Invariably, the largest source of uncertainty occurs during the initial sampling. Coarse blanks are used to monitor cross-contamination between samples or from sample preparation equipment. Furthermore, each of these QC sample types can be used to discover possible sample mix-ups. Supplementary material: An Excel spreadsheet for the calculation of the average coefficient of variation (CV AVE ) (Appendix C) is available at https://doi.org/10.6084/m9.figshare.c.7070137 Thematic collection: This article is part of the Reviews in Exploration Geochemistry collection available at: https://www.lyellcollection.org/topic/collections/reviews-in-exploration-geochemistry

Comparison of the sigma metrics using the total error allowable algorithm with variation of bias source

Sigma Metrics, as a quality indicator, have been widely applied in clinical laboratories to assess the performance of analytical methods. Described in the document Clinical and Laboratory Standards Institute (CLSI) EP15- A3, the use of target values can be sourced from certified reference standards, survey materials from the Proficiency Testing (PT)/External Quality Assessment (EQA), materials used in inter-laboratory quality control programs and internal quality control materials with predetermined targets. This research aims to determine whether there is a difference in the sigma metrics between the bias derived from the manufacturer's target value and those from the peer group source in the External Quality Assurance Services (EQAS) program. The research methodology employed is descriptive comparative analysis, utilizing the results of material inspection data for 15 internal quality control parameters of Clinical Chemistry over a span of 2 years at the Pramita Laboratory in Bandung. The calculation of the sigma metrics commences with computing the coefficient of variation (CV), and the appropriate Total Error aalowable (Tea) sources for each parameter are determined beforehand using the TEa algorithm. The research findings indicate a difference between the sigma metrics derived from the manufacturer's target value and those from the EQAS-peer group target value, accounting for 33% or 10 parameters out of the total parameters with 2 levels of inspection are calculated on the sigma scale. However, in 67% or 20 parameters out of the total parameters, no such difference is observed. Bias associated with the target value from the manufacturer and the EQAS peer group shows no significant difference, suggesting that the laboratory can utilize pre-existing target values confidently.

Ten-year results of an international external quality control programme for measurement of anti-tuberculosis drug concentrations.

Participation in an external (interlaboratory) quality control (QC) programme is an essential part of quality assurance as it provides laboratories with valuable insights into their analytical performance. We describe the 10 year results of an international QC programme for the measurement of anti-tuberculosis (TB) drugs. Each year, two rounds were organized in which serum (or plasma) samples, spiked with known concentrations of anti-TB drugs, were provided to participating laboratories for analysis. Reported measurements within 80%-120% of weighed-in concentrations were considered accurate. Mixed model linear regression was performed to assess the effect of the measured drug, concentration level, analytical technique and performing laboratory on the absolute inaccuracy. By 2022, 31 laboratories had participated in the QC programme and 13 anti-TB drugs and metabolites were included. In total 1407 measurements were reported. First-line TB drugs (isoniazid, rifampicin, pyrazinamide and ethambutol) represented 58% of all measurements. Overall, 83.2% of 1407 measurements were accurate, and the median absolute inaccuracy was 7.3% (IQR, 3.3%-15.1%). The absolute inaccuracy was related to the measured anti-TB drug and to the performing laboratory, but not to the concentration level or to the analytical technique used. The median absolute inaccuracies of rifampicin and isoniazid were relatively high (10.2% and 10.9%, respectively). The 10 year results of this external QC programme illustrate the need for continuous external QC for the measurement of anti-TB drugs for research and patient care purposes, because one in six measurements was inaccurate. Participation in the programme alerts laboratories to previously undetected analytical problems.