Canadian Society Of Clinical Chemists Research Articles

Validating the NIH LDL-C equation for provincial implementation in Alberta

BackgroundLDL-C, a cardiovascular disease risk assessment biomarker, is commonly calculated using the Friedewald equation. The NIH equation overcomes several limitations of the Friedewald equation. Consistent with the Canadian Society of Clinical Chemists (CSCC) lipid reporting recommendations, we assessed the NIH LDL-C equation in Alberta prior to its provincial implementation. Methods1-year (01/01/2021–12/31/2021) of lipid results (n = 1,486,584 after data cleaning) were obtained from five analytical instrument groups used across Alberta. Analyses were performed on all data and after separating by age, analytical instrument group, and fasting status. The correlation between Friedewald- and NIH-calculated LDL-C and between Friedewald- and NIH-calculated LDL-C difference and each lipid parameter, was determined. The frequency of unreportable/inaccurate LDL-C results was compared between the two equations. The concordance between the two equations and with non-HDL-C was determined at LDL-C thresholds. Lastly, LDL-C calculated by Friedewald, NIH, and Martin-Hopkins equations was compared to density-gradient ultracentrifugation. ResultsFriedewald- and NIH-calculated LDL-C exhibit the strongest correlation when triglycerides ≤ 4.52 mmol/L. The difference between Friedewald- and NIH-calculated LDL-C increases with decreasing LDL-C concentration. The NIH equation yields fewer inaccurate results (0.35 % vs. 22.0 %). The percent agreement between equations was > 96 % at all LDL-C thresholds, suggesting most patients will not require treatment changes. NIH-calculated LDL-C exhibited better agreement with non-HDL-C when triglycerides ≤ 9.04 mmol/L and better correlated with LDL-C measured by ultracentrifugation (r2 = 0.926 vs. 0.775 (Friedewald) and 0.863 (Martin-Hopkins)). Results were consistent across age, analytical instrument group, and fasting status. ConclusionsOur findings demonstrate the benefits of implementing the NIH equation across Alberta.

Selected abstracts presented at the annual conference of the Canadian Society of Clinical Chemists (CSCC), 2023

Selected abstracts presented at the annual conference of the Canadian Society of Clinical Chemists (CSCC), 2023

Reference Interval Harmonization: Harnessing the Power of Big Data Analytics to Derive Common Reference Intervals across Populations and Testing Platforms.

Harmonization in laboratory medicine is essential for consistent and accurate clinical decision-making. There is significant and unwarranted variation in reference intervals (RIs) used by laboratories for assays with established analytical traceability. The Canadian Society of Clinical Chemists (CSCC) Working Group on Reference Interval Harmonization (hRI-WG) aims to establish harmonized RIs (hRIs) for laboratory tests and support implementation. Harnessing the power of big data, laboratory results were collected across populations and testing platforms to derive common adult RIs for 16 biochemical markers. A novel comprehensive approach was established, including: (a) analysis of big data from community laboratories across Canada; (b) statistical evaluation of age, sex, and analytical differences; (c) derivation of hRIs using the refineR method; and (d) verification of proposed hRIs across 9 laboratories with different instrumentation using serum and plasma samples collected from healthy Canadian adults. Harmonized RIs were calculated for all assays using the refineR method, except free thyroxine. Derived hRIs met proposed verification criterion across 9 laboratories and 5 manufacturers for alkaline phosphatase, albumin (bromocresol green), chloride, lactate dehydrogenase, magnesium, phosphate, potassium (serum), and total protein (serum). Further investigation is needed for some analytes due to failure to meet verification criteria in one or more laboratories (albumin [bromocresol purple], calcium, total carbon dioxide, total bilirubin, and sodium) or concern regarding excessively wide hRIs (alanine aminotransferase, creatinine, and thyroid stimulating hormone). We report a novel data-driven approach for RI harmonization. Findings support feasibility of RI harmonization for several analytes; however, some presented challenges, highlighting limitations that need to be considered in harmonization and big data analytics.

Establishing quality indicators for point of care glucose testing: recommendations from the Canadian Society for Clinical Chemists Point of Care Testing and Quality Indicators Special Interest Groups.

Monitoring quality indicators (QIs) is an important part of laboratory quality assurance (QA). Here, the Canadian Society of Clinical Chemists (CSCC) Point of Care Testing (POCT) and QI Special Interest Groups describe a process for establishing and monitoring QIs for POCT glucose testing. Key, error prone steps in the POCT glucose testing process were collaboratively mapped out, followed by risk assessment for each step. Steps with the highest risk and ability to detect a non-conformance were chosen for follow-up. These were positive patient identification (PPID) and repeat of critically high glucose measurements. Participating sites were asked to submit aggregate data for these indicators from their site(s) for a one-month period. The PPID QI was also included as part of a national QI monitoring program for which fifty-seven sites submitted data. The percentage of POCT glucose tests performed without valid PPID ranged from 0-87%. Sites without Admission-Discharge-Transfer (ADT) connectivity to POCT meters were among those with the highest percentage of POCT glucose tests performed without valid PPID. The percentage repeated critically high glucose measurements ranged from 0-50%, indicating low compliance with this recommendation. A high rate of discordance was also noted when critically high POCT glucose measurements were repeated, demonstrating the importance of repeat testing prior to insulin administration. Here, a process for establishing these QIs is described, with preliminary data for two QIs chosen from this process. The findings demonstrate the importance of QIs for identification and comparative performance monitoring of non-conformances to improve POCT quality.

Selected Abstracts Presented at the Annual Conference of the Canadian Society of Clinical Chemists (CSCC), 2022

Selected Abstracts Presented at the Annual Conference of the Canadian Society of Clinical Chemists (CSCC), 2022

The Impact of Low-Density Lipoprotein Equation Changes on Cholesterol Treatment in Canada

BackgroundIn cardiovascular disease prevention, low-density lipoprotein cholesterol (LDL-C) values guide treatment for lowering cholesterol level. After 50 years of clinical laboratories using the Friedewald LDL-C equation, the Canadian Society of Clinical Chemists recently recommended adoption of the new and more accurate Sampson / U.S. National Institutes of Health (NIH) LDL-C equation. Here, we estimate the anticipated population-level impact of this equation change. MethodsWe compared lipid profiles from the Canadian Health Measures Survey (CHMS) year 2019 to those from the National Health and Nutrition Examination Survey (NHANES) years 2017 to 2020. Then, based on 10,828 participants in the latter, we calculated the impact of changing the LDL-C equation from the Friedewald to the Sampson. ResultsSampson- and Friedewald-equation LDL-C values are strongly correlated (r = 0.99, P < 0.001), but differences between them increase with both higher triglyceride and lower LDL-C values. We evaluated the impact of these discordances using LDL-C treatment thresholds from the 2021 Canadian Cardiovascular Society lipid guidelines. Among patients who take cholesterol-lowering medications, the Sampson equation reclassifies 3.3% more patients (95% confidence interval 2.2% to 4.9%), or about 123,000 individuals, as meeting the criteria for treatment intensification. ConclusionAlthough changing the LDL-C equation used from the Friedewald to the Sampson affects only a small proportion of the population, an estimated 123,000 Canadians who are taking cholesterol-lowering medications may need to intensify treatment to lower their cholesterol level, due to small absolute changes around guideline threshold values of LDL-C.

Canadian Society of Clinical Chemists (CSCC) consensus guidance for testing, selection and quality management of SARS-CoV-2 point-of-care tests

ObjectivesA consensus guidance is provided for testing, utility and verification of SARS-CoV-2 point-of-care test (POCT) performance and implementation of a quality management program, focusing on nucleic acid and antigen targeted technologies. Design and MethodsThe recommendations are based on current literature and expert opinion from the members of Canadian Society of Clinical Chemists (CSCC), and are intended for use inside or outside of healthcare settings that have varied levels of expertise and experience with POCT. Results and ConclusionsHere we discuss sampling requirements, biosafety, SARS-CoV-2 point-of-care testing methodologies (with focus on Health Canada approved tests), test performance and limitations, test selection, testing utility, development and implementation of quality management systems, quality improvement, and medical and scientific oversight.

A Snapshot of Lipid-Reporting Practices in Canadian Clinical Laboratories: An Urgent Need for Harmonisation

To effectively implement the Canadian Cardiovascular Society (CCS) guidelines for dyslipidemia management into clinical laboratories, clear recommendations for lipid reporting are essential. In this study, the Canadian Society of Clinical Chemists Working Group on Reference Interval Harmonisation surveyed Canadian laboratories on adult lipid reporting practices to set a foundation for the development and implementation of harmonised lipid reporting across Canada. Key aspects of the survey asked laboratories: what reporting parameters were in place to assess lipid results; what interpretative comments were provided; whether nonfasting lipids were permitted and, if so, what strategy was used to document fasting status; and whether there was interest in implementing a harmonised lipid report. A total of 101 laboratories were represented by 24 respondents, as many responses were submitted by laboratory networks that included more than 1 laboratory. There was at least 1 response from 9 Canadian provinces and representation across 5 testing platforms. Upper and lower limits for lipid parameters and referenced source of limits varied substantially across laboratories, with only 56% of laboratories (9 respondents) referencing the 2016 CCS guidelines. Eighty-six percent of laboratories (19 respondents) report nonfasting lipids, although the method of documenting nonfasting status varied. Overall, 36% of laboratories (8 respondents) reported interest in implementing a harmonised lipid report. Assessment of current lipid-reporting practices supports the need for harmonised lipid reporting across Canada. Development of a harmonised lipid report for the adult population, consistent with up-to-date Canadian guidelines, will improve continuity of lipid test interpretation across Canada and improve clinical decision making.

Selected abstracts presented at the annual conference of the Canadian Society of Clinical Chemists (CSCC), 2020

Alkaline phosphatase (ALP) serves as a biomarker for diagnosing several types of diseases in adults; nonetheless, its use is restricted in children because of changes in ALP activity during different physiological phases. The present study aimed to investigate ALP activity and its dynamics in children of different ages to establish the reference values for ALP activity in children.Total 167,625 samples of children aged 0–18 years were enrolled in this study. ALP activity was measured using the 4-nitrophenyl-1-phosphate disodium salt (4-NPP)–2-amino-2-methyl-1-propanol (AMP) method with an automatic biochemical analyzer. Patients with known diagnoses that may affect ALP activity were excluded. A percentile curve was plotted using MATLAB software, and the curve was fitted using the skewness–median–coefficient of variation (LMS) method.ALP activity reached the highest peak at 12–13 years of age and then gradually decreased to the lowest peak at 18–19 years of age in boys, whereas it reached the highest at 10–11 years and then gradually reduced to the lowest at 17–18 years in girls. Furthermore, the highest peak of ALP activity appeared substantially earlier in children of either sex in China than in those in Germany.We showed the dynamics of ALP activity in both boys and girls between the ages of 0 and 18 years in China and compared the difference in ALP activity between children in China and Germany. Our findings provide a reference for clinicians.

Canadian society of clinical chemists (CSCC) interim consensus guidance for testing and reporting of SARS-CoV-2 serology

Clinical laboratories across the world are working to validate and perform testing for SARS-CoV-2 antibodies. Herein, we present interim consensus guidance for Canadian clinical laboratories testing and reporting SARS-CoV-2 serology, with emphasis on the capabilities and limitations of these tests and recommendations for interpretative comments in an effort to achieve harmonized laboratory practices. The consensus document provides a broad overview of topics including sample type and contamination risk; kinetics of antibody response to COVID-19 and the impact on serology testing; clinical utility of SARS-CoV-2 serology testing; clinical performance of commercial laboratory-based assays commonly deployed in North America; recommendations for interim reporting; utility of SARS-CoV-2 antibody testing for pediatric patients; and utility of point-of-care testing. The information is based on the current literature and is subject to change as additional information becomes available.

Selected Abstracts Presented at the Annual Conference of the Canadian Society of Clinical Chemists (CSCC), Saint John, NB, 2-5 June 2019

Low serum PON1 activities (paraoxon, phenyl-acetate or lactone substrates) are associated with coronary heart disease (CHD). We investigated the rate of diazoxon hydrolysis by PON1 in a population with CHD.Case- control study of 410 subjects with CHD and 274 controls. PON1 activity towards paraoxon and diazoxon, PON1 serum concentration and the PON1–55 and 192 polymorphisms were determined.There were no differences in the distribution of the PON1–55 or PON1–192 genotypes between the CHD and controls, however, PON1 activity towards diazoxon (DIAZ) was significantly (+160%) higher in CHD. In the control population, DIAZ was significantly different between the PON1–192 genotypes in the order QQ > QR > RR (P < .001). However, in CHD the order was QQ > QR = RR. In CHD DIAZ was significantly higher in all the PON1–192 and 55 genotypes compared to controls. In both populations DIAZ was significantly different between the PON1–55 genotypes in the order LL > LM > MM (P < .001).If this result can be replicated in other studies and/or with other PON1 substrates, there may be major diagnostic and mechanistic implications for the relationship of PON1 and CHD.

Selected Abstracts Presented at the Annual Conference of the Canadian Society of Clinical Chemists (CSCC), Ottawa, June 3-6, 2018

Selected Abstracts Presented at the Annual Conference of the Canadian Society of Clinical Chemists (CSCC), Ottawa, June 3-6, 2018

Candidate recommendations for protein electrophoresis reporting from the Canadian Society of Clinical Chemists Monoclonal Gammopathy Working Group

Protein electrophoresis is commonly used as an aid in the diagnosis of monoclonal gammopathies and is performed in many laboratories in Canada and throughout the world. However, unlike many other diagnostic tests, there is limited guidance for standardization and neither guidance nor specific recommendations for clinical reporting of serum (SPE) or urine (UPE) protein electrophoresis and immunotyping available in the literature. Therefore, a Canadian effort was undertaken to recommend standards that cover all aspects of clinical reporting with an ultimate goal towards reporting standardization. The Canadian Society of Clinical Chemists (CSCC) Monoclonal Gammopathy Interest Group (MGIG), which is composed of CSCC members with an interest in protein electrophoresis, has formed a Monoclonal Gammopathy Working Group (MGWG) to take initial steps towards standardization of SPE, UPE and immunotyping. Candidate standardization recommendations were developed, discussed and voted upon by the MGWG. Candidate recommendations that achieved 90% agreement are presented as consensus recommendations. Recommendations that did not achieve 90% consensus remain candidate recommendations and are presented with accompanying MGWG discussion. Eleven consensus recommendations along with candidate recommendations for nomenclature, protein fraction reporting, test utilization, interference handling and interpretive reporting options are presented.

National Survey of Adult and Pediatric Reference Intervals in Clinical Laboratories across Canada: A Report of the CSCC Working Group on Reference Interval Harmonization

ObjectiveReference intervals are widely used decision-making tools in laboratory medicine, serving as health-associated standards to interpret laboratory test results. Numerous studies have shown wide variation in reference intervals, even between laboratories using assays from the same manufacturer. Lack of consistency in either sample measurement or reference intervals across laboratories challenges the expectation of standardized patient care regardless of testing location. Here, we present data from a national survey conducted by the Canadian Society of Clinical Chemists (CSCC) Reference Interval Harmonization (hRI) Working Group that examines variation in laboratory reference sample measurements, as well as pediatric and adult reference intervals currently used in clinical practice across Canada. Design and MethodsData on reference intervals currently used by 37 laboratories were collected through a national survey to examine the variation in reference intervals for seven common laboratory tests. Additionally, 40 clinical laboratories participated in a baseline assessment by measuring six analytes in a reference sample. ResultsOf the seven analytes examined, alanine aminotransferase (ALT), alkaline phosphatase (ALP), and creatinine reference intervals were most variable. As expected, reference interval variation was more substantial in the pediatric population and varied between laboratories using the same instrumentation. Reference sample results differed between laboratories, particularly for ALT and free thyroxine (FT4). Reference interval variation was greater than test result variation for the majority of analytes. ConclusionIt is evident that there is a critical lack of harmonization in laboratory reference intervals, particularly for the pediatric population. Furthermore, the observed variation in reference intervals across instruments cannot be explained by the bias between the results obtained on instruments by different manufacturers.

Position statement of the Canadian Society of Clinical Chemists and Canadian Association of Medical Biochemists on hemoglobin A1c measurement and reporting

Position statement of the Canadian Society of Clinical Chemists and Canadian Association of Medical Biochemists on hemoglobin A1c measurement and reporting

Cardiac troponin testing in the acute care setting: Ordering, reporting, and high sensitivity assays—an update from the Canadian society of clinical chemists (CSCC); the case for age related acute myocardial infarction (AMI) cut-offs

Cardiac troponin testing in the acute care setting: Ordering, reporting, and high sensitivity assays—an update from the Canadian society of clinical chemists (CSCC); the case for age related acute myocardial infarction (AMI) cut-offs

Abstracts of papers presented at the 2007 meeting of the Canadian Society of Clinical Chemists

Abstracts of papers presented at the 2007 meeting of the Canadian Society of Clinical Chemists

The Canadian Society of Clinical Chemists: highlights of its first 50 years

This article has been written to mark the 50th anniversary of the Canadian Society of Clinical Chemists (CSCC). It is not an exhaustive history of CSCC's activities but rather a review of many of the highlights that the Society and its members have experienced since its founding in October 1956. The names of many members who made important contributions to CSCC's development (but by no means all) are mentioned in the text. The historical material is presented by the decade but with blurred boundaries, as noteworthy advances in CSCC's history have most often developed gradually over several years and the terms of office of several CSCC Councils. From a founding roster of slightly over 70 members, the membership has grown to several hundred. The two main objectives for the Society's founding were stated by one of the three Montrealers who extended the original invitation, Dr. William S. Bauld: “ to raise the standards of performance, and to raise the professional standing of clinical chemists”. The early reports of committees on Instrumentation, Methods and Quality Control had rapid impact on individual members' laboratory practices across the country. The struggle for recognition of clinical chemists by other health professions inside and outside the clinical laboratories has taken much longer and has consisted of a long series of incremental successes through certification by examination, training programs, continuing education and, ultimately, the formation in 1986 of the Canadian Academy of Clinical Biochemistry. The CSCC's means of intra- and inter-communication with external organizations consist of its newsletter CSCC News, its scientific journal Clinical Biochemistry (established in 1967), and its more recently created website www.cscc.ca (1997). These three mechanisms ensure exchange of information between the officers of CSCC Council and the general membership and among members as well. National and international conferences have offered the newest scientific discoveries pertinent to the profession, exhibits featuring the latest in increasingly sophisticated instrumentation and reagents, and abundant opportunity to exchange information informally with old and newly met colleagues. By their contributions to the International Federation of Clinical Chemistry and the International Union of Pure and Applied Chemistry, CSCC members continue to play important roles far beyond Canada's borders.

48th Annual Conference of the Canadian Society of Clinical Chemists and the Canadian Association of Medical Biochemists June 5–10, 2004 London, Ontario

48th Annual Conference of the Canadian Society of Clinical Chemists and the Canadian Association of Medical Biochemists June 5–10, 2004 London, Ontario

Abstracts from the Canadian society of clinical chemists’ annual conference: Saint-sauveur, Québec, June 1–5, 2003

Abstracts from the Canadian society of clinical chemists’ annual conference: Saint-sauveur, Québec, June 1–5, 2003