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.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

The Fracture Risk Assessment Tool (FRAX®) predicts fracture risk in patients with chronic kidney disease.

The Fracture Risk Assessment Tool (FRAX®) was developed to predict fracture risk in the general population, but its applicability to patients with chronic kidney disease (CKD) is unknown. Using the Manitoba Bone Mineral Density (BMD) Database, we identified adults not receiving dialysis with available serum creatinine measurements and bone densitometry within 1 year. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Incident major osteoporotic fractures and hip fractures were ascertained from population-based health care databases. The performance of FRAX, derived without and with BMD, was studied in relation to CKD stage. Among 10,099 subjects (mean age 64 ± 13 years, 13.0% male), 2,154 had eGFR 30-60 mL/min/1.73 m2 (CKD stage 3) and 590 had eGFR <30 mL/min/1.73 m2 (CKD stages 4-5). During a 5-year observation period, 772 individuals experienced a major osteoporotic fracture and 226 had a hip fracture. FRAX predicted risk for major osteoporotic fracture and hip fracture in all eGFR strata. For every standard deviation increase in FRAX score derived with BMD, the hazard ratio (HR) for hip fracture was 4.54 (95% confidence interval [CI] 3.57-5.77) in individuals with eGFR ≥ 60 mL/min/1.73m2, 4.52 (95% CI 3.15-6.49) in individuals with eGFR 30-60 mL/min/1.73m2, and 3.10 (95% CI 1.80-5.33) in individuals with eGFR <30 mL/min/1.73m2. The relationship between FRAX and major osteoporotic fracture was stronger in those with CKD compared to those with preserved eGFR. These findings support the use of FRAX to risk stratify patients with non-dialysis CKD for major osteoporotic fractures and hip fractures.

New solutions to old problems: A practical approach to identify samples with intravenous fluid contamination in clinical laboratories.

OBJECTIVES: Contamination with intravenous (IV) fluids is a common cause of specimen rejection or erroneous results in hospitalized patients. Identification of contaminated samples can be difficult. Common measures such as failed delta checks may not be adequately sensitive nor specific. This study aimed to determine detection criteria using commonly ordered tests to identify IV fluid contamination and validate the use of these criteria. METHODS: Confirmed contaminated and non-contaminated samples were used to identify patterns in laboratory results to develop criteria to detect IV fluid contamination. The proposed criteria were implemented at a tertiary care hospital laboratory to assess performance prospectively for 6 months, and applied to retrospective chemistry results from 3 hospitals and 1 community lab to determine feasibility and flagging rates. The algorithm was also tested at an external institution for transferability. RESULTS: The proposed algorithm had a positive predictive value of 92 %, negative predictive value of 91 % and overall agreement of 92 % when two or more criteria are met (n = 214). The flagging rates were 0.03 % to 0.07 % for hospital and 0.003 % for community laboratories. CONCLUSIONS: The proposed algorithm identified true contamination with low false flagging rates in tertiary care urban hospital laboratories. Retrospective and prospective analysis suggest the algorithm is suitable for implementation in clinical laboratories to identify samples with possible IV fluid contamination for further investigation.

Imprecision of high-sensitivity cardiac troponin assays at the female 99th-percentile.

BACKGROUND: An analytical benchmark for high-sensitivity cardiac troponin (hs-cTn) assays is to achieve a coefficient of variation (CV) of ≤ 10.0 % at the 99th percentile upper reference limit (URL) used for the diagnosis of myocardial infarction. Few prospective multicenter studies have evaluated assay imprecision and none have determined precision at the female URL which is lower than the male URL for all cardiac troponin assays. METHODS: Human serum and plasma matrix samples were constructed to yield hs-cTn concentrations near the female URLs for the Abbott, Beckman, Roche, and Siemens hs-cTn assays. These materials were sent (on dry ice) to 35 Canadian hospital laboratories (n = 64 instruments evaluated) participating in a larger clinical trial, with instructions for storage, handling, and monthly testing over one year. The mean concentration, standard deviation, and CV for each instrument type and an overall pooled CV for each manufacturer were calculated. RESULTS: The CVs for all individual instruments and overall were ≤ 10.0 % for two manufacturers (Abbott CVpooled = 6.3 % and Beckman CVpooled = 7.0 %). One of four Siemens Atellica instruments yielded a CV > 10.0 % (CVpooled = 7.7 %), whereas 15 of 41 Roche instruments yielded CVs > 10.0 % at the female URL of 9 ng/L used worldwide (6 cobas e411, 1 cobas e601, 4 cobas e602, and 4 cobas e801) (CVpooled = 11.7 %). Four Roche instruments also yielded CVs > 10.0 % near the female URL of 14 ng/L used in the United States (CVpooled = 8.5 %). CONCLUSIONS: The number of instruments achieving a CV ≤ 10.0 % at the female 99th-percentile URL varies by manufacturer and by instrument. Monitoring assay precision at the female URL is necessary for some assays to ensure optimal use of this threshold in clinical practice.

Strategies used in managing conversations about prostate-specific antigen (PSA) testing among family physicians (FPs): a qualitative study.

OBJECTIVES: Screening for prostate cancer in healthy asymptomatic men using the prostate-specific antigen (PSA) test is controversial due to conflicting recommendations from and a lack of strong evidence regarding the benefit of population-based screening. In Canada and internationally, there is variability in how family physicians (FPs) approach PSA testing in asymptomatic men. The purpose of our study was to explore how family FPs approach discussions with their male patients around PSA testing in Manitoba, Canada. DESIGN: Qualitative descriptive study. SETTING AND PARTICIPANTS: High-ordering and median-ordering FPs were invited to participate in an interview. In addition to exploring practice behaviours around PSA testing, participants were asked to elaborate on their typical discussion with asymptomatic men who request a PSA test or other tests and procedures that they do not feel are clinically warranted. Data were analysed inductively using a constant-comparison approach. RESULTS: There were important variations between high-ordering and median-ordering FP's approaches to discussing PSA testing. Strategies to facilitate conversations were more frequently identified by median-ordering physicians and often included methods to facilitate assessing their patient's understanding and values. In addition to decision aids, median-ordering FPs used motivational interviewing to tailor a discussion, organised their practice structure and workflow habits in a way that enhanced patient-provider discussions and leveraged 'new' evidence and other aids to guide conversations with men. CONCLUSION: We found that high-ordering FPs tended to use the PSA test for screening asymptomatic men with limited shared decision-making. Median-ordering FPs used conversational strategies that emphasised uncertainty of benefit and potential risk and did not present the test as a recommendation.

Evaluation of commercial SARS-CoV-2 serological assays in Canadian public health laboratories.

The COVID-19 pandemic has led to the influx of immunoassays for the detection of antibodies towards severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into the global market. The Canadian Public Health Laboratory Network Serology Task Force undertook a nationwide evaluation of twelve laboratory and 6 point-of-care based commercial serological assays for the detection of SARS-CoV-2 antibodies. We determined that there was considerable variability in the performance of individual tests and that an orthogonal testing algorithm should be prioritized to maximize the accuracy and comparability of results across the country. The manual enzyme immunoassays and point-of-care tests evaluated had lower specificity and increased coefficients of variation compared to automated enzyme immunoassays platforms putting into question their utility for large-scale sero-surveillance. Overall, the data presented here provide a comprehensive approach for applying accurate serological assays for longitudinal sero-surveillance and vaccine trials while informing Canadian public health policy.

Nephrology visits and health care resource use before and after reporting estimated glomerular filtration rate.

CONTEXT: Laboratory reporting of estimated glomerular filtration rate (GFR) has been widely implemented, with limited evaluation. OBJECTIVE: To examine trends in nephrologist visits and health care resource use before and after estimated GFR reporting. DESIGN, SETTING, AND PATIENTS: Community-based cohort study (N = 1,135,968) with time-series analysis. Participants were identified from a laboratory registry in Alberta, Canada, and followed up from May 15, 2003, to March 14, 2007 (with estimated GFR reporting implemented October 15, 2004). MAIN OUTCOME MEASURE: Nephrologist visits and patient management. RESULTS: Following estimated GFR reporting, the rate of first outpatient visits to a nephrologist for patients with chronic kidney disease (CKD; estimated GFR <60 mL/min/1.73 m(2)) increased by 17.5 (95% confidence interval [CI], 16.5-18.6) visits per 10,000 CKD patients per month, corresponding to a relative increase from baseline of 68.4% (95% CI, 65.7%-71.2%). There was no association between estimated GFR reporting and rate of first nephrologist visit among patients without CKD. Among patients with an estimated GFR of less than 30 mL/min/1.73 m(2), the rate of first nephrologist visits increased by 134.4 (95% CI, 60.0-208.7) visits per 10,000 patients per month. This increase was predominantly seen in women, patients aged 46 to 65 years as well as those aged 86 years or older, and those with hypertension, diabetes, and comorbidity. Reporting of estimated GFR was not associated with increased rates of internal medicine or general practitioner visits or increased use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers among patients with CKD and proteinuria or the subgroup limited to patients with diabetes. CONCLUSIONS: Reporting of estimated GFR was associated with an increase in first nephrologist visits, particularly among patients with more severe kidney dysfunction, women, middle-aged and very elderly patients, and those with comorbidities. Any effect on outcomes remains to be shown.

Overview of the Alberta Kidney Disease Network.

BACKGROUND: The Alberta Kidney Disease Network is a collaborative nephrology research organization based on a central repository of laboratory and administrative data from the Canadian province of Alberta. DESCRIPTION: The laboratory data within the Alberta Kidney Disease Network can be used to define patient populations, such as individuals with chronic kidney disease (using serum creatinine measurements to estimate kidney function) or anemia (using hemoglobin measurements). The administrative data within the Alberta Kidney Disease Network can also be used to define cohorts with common medical conditions such as hypertension and diabetes. Linkage of data sources permits assessment of socio-demographic information, clinical variables including comorbidity, as well as ascertainment of relevant outcomes such as health service encounters and events, the occurrence of new specified clinical outcomes and mortality. CONCLUSION: The unique ability to combine laboratory and administrative data for a large geographically defined population provides a rich data source not only for research purposes but for policy development and to guide the delivery of health care. This research model based on computerized laboratory data could serve as a prototype for the study of other chronic conditions.

Increased rates of 25-hydroxy vitamin D testing: Dissecting a modern epidemic.

INTRODUCTION: Laboratories have noted marked increases in the analysis of 25-hydroxy vitamin D (25(OH)D) in recent decades. Our objectives were to describe the annual number of 25(OH)D tests, examine the characteristics of those tested and those ordering them, and determine the proportion of potentially unnecessary tests in Manitoba. METHODS: Manitoba residents who were tested between 2006/7 and 2012/13 had their data anonymously linked to Manitoba Centre for Health Policy comprehensive administrative datasets. Patient and physician characteristics, location of residence, and 25(OH)D concentrations were determined. Descriptive statistics and multivariable regression models were utilized. RESULTS: There was a quadrupling in testing from 2006 to 2013, with >20,000 tests performed in 2012/13. The median annual number of tests was one per patient; the maximum was >10 tests per year. Adult females had twice the number of tests compared to males (p < 0.001). There was a rise in 25(OH)D concentrations over time with hypervitaminosis D increasing disproportionately (2006/7 to 212/13 (0% vs. 0.15%, p < 0.001)). Apparently unnecessary testing rose by 1/3 over time, frequently ordered by Family Medicine practitioners. A revised 25(OH)D requisition resulted in striking reduction of 25(OH)D requests (~80%). DISCUSSION: Manitoba noted a rapid increase in testing, and rise in 25(OH)D concentrations with levels that may be associated with toxicities; both have been reported in other jurisdictions. There appeared to a striking rise in 'unnecessary' tests. We similarly report the benefit of the implementation of a mandatory requisition specifying eligibility criteria for 25(OH)D and education about appropriate testing.

Biochemistry testing associated with pregnancy and the newborn period -- a lot has changed since you were a baby!

Everyone has been a newborn, and everyone's mother has been pregnant. Despite the commonality of these events, medical care and the clinical chemistry laboratory's role in it have changed remarkably over the last 50 years. This review is a historical overview of clinical chemistry testing that is related to pregnancy and the newborn period.

A cluster randomized trial of an enhanced eGFR prompt in chronic kidney disease.

BACKGROUND AND OBJECTIVES: Despite reporting estimated GFR (eGFR), use of evidence-based interventions in CKD remains suboptimal. This study sought to determine the effect of an enhanced eGFR laboratory prompt containing specific management recommendations, compared with standard eGFR reporting in CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A cluster randomized trial of a standard or enhanced eGFR laboratory prompt was performed in 93 primary care practices in Alberta, Canada. Although all adult patients with CKD (eGFR <60 ml/min per 1.73 m(2)) were included, medication data were only available for elderly patients (aged ≥66 years). The primary outcome, the proportion of patients with diabetes or proteinuria receiving an angiotensin converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB), was assessed in elderly CKD patients. RESULTS: There were 5444 elderly CKD patients with diabetes or proteinuria who were eligible for primary outcome assessment, irrespective of baseline ACEi/ARB use. ACEi/ARB use in the subsequent year was 77.1% and 76.9% in the standard and enhanced prompt groups, respectively. In the subgroup of elderly patients with an eGFR <30 ml/min per 1.73 m(2), ACEi/ARB use was higher in the enhanced prompt group. Among 22,092 CKD patients, there was no difference in the likelihood of a composite clinical outcome (death, ESRD, doubling of serum creatinine, or hospitalization for myocardial infarction, heart failure, or stroke) over a median of 2.1 years. CONCLUSIONS: In elderly patients with CKD and an indication for ACEi/ARB, an enhanced laboratory prompt did not increase use of these medications.

High sensitivity troponin T concentrations in patients undergoing noncardiac surgery: a prospective cohort study.

OBJECTIVES: To determine the proportion of noncardiac surgery patients exceeding the published 99th percentile or change criteria with the high sensitivity Troponin T (hs-TnT) assay. DESIGN AND METHODS: We measured hs-TnT preoperatively and postoperatively on days 1, 2 and 3 in 325 adults. RESULTS: Postoperatively 45% (95% CI: 39-50%) of patients had hs-TnT≥14ng/L and 22% (95% CI:17-26%) had an elevation (≥14ng/L) and change (>85%) in hs-TnT. CONCLUSION: Further research is needed to inform the optimal hs-TnT threshold and change in this setting.