Quality Assurance in Clinical Chemistry: A Touch of Statistics and A Lot of Common Sense

Issues in assessing analytical performance specifications in healthcare systems assembling multiple laboratories and measuring systems

Analytical performance specifications (APS) are usually compared to the intermediate reproducibility uncertainty of measuring a particular measurand using a single in vitro diagnostic medical device (IVD MD). Healthcare systems assembling multiple laboratories that include several IVD MDs and cater to patients suffering from long-term disease conditions mean that samples from a patient are analyzed using a few IVD MDs, sometimes from different manufacturers, but rarely all IVD MDs in the healthcare system. The reproducibility uncertainty for results of a measurand measured within a healthcare system and the components of this measurement uncertainty is useful in strategies to minimize bias and overall measurement uncertainty within the healthcare system. The root mean squares deviation (RMSD) calculated as the sample standard deviation (SD) and relative SD includes both imprecision and bias and is appropriate for expressing such uncertainties. Results from commutable stabilized internal and external control samples, from measuring split natural patient samples or using big-data techniques, are essential in monitoring bias and measurement uncertainties in healthcare systems. Variance component analysis (VCA) can be employed to quantify the relative contributions of the most influential factors causing measurement uncertainty. Such results represent invaluable information for minimizing measurement uncertainty in the interest of the healthcare system's patients.

Practical considerations on redesigning internal quality control process to verify the traceability of clinical results for decision-making

Traceability is an important tool in the harmonization and standardization of reporting laboratory results, making them comparable across measurement systems. Driven by International Standardization Organization (ISO) 15189 accreditation requirements, medical laboratories have entered the era of metrological traceability. Although calibrators are a key component in the entire metrological traceability system, there is controversy over internal quality control (IQC) materials. It has been proposed that trueness materials supplied by the system's manufacturer with metrological traceability can be used to confirm that the performance of the measuring system is properly unbiased. This article focuses on the implementation challenges and operational hurdles of applying traceability concepts to IQC materials for trueness verification in medical laboratories regarding the most recent 2022 edition of ISO 15189 standard requirements for IQC and metrological traceability. There are practical considerations concerning the acquiring of IQC materials. We must acknowledge the limitations and restrictions that manufacturers and laboratories face before the recommendations can be applied in routine practices.

Arginine, as a Key Indicator for Real-Time Stability Monitoring of Quality Control in the Newborn Screening Test Using Dried Blood Spot

Dried blood spots (DBS) have advantages such as minimizing blood collection volume and the distress to neonate. DBS have been used for tandem mass spectrometry (MS/MS)-based newborn screening tests (NST) of amino acid (AA) and acylcarnitine. The Newborn Screening Quality Assurance Program (NSQAP) have been provided quality control (QC) materials for MS/MS, as DBS cards. The NSQAP is generally provided within 14 months of the shelf life and the recommended storage condition is at −10 °C to −30 °C. Previously, several accelerated degradation studies had been performed to determine the transportation stability and short-term stability of AAs and acylcarnitines in DBS. However, the experimental condition is markedly different to the storage condition. We performed long-term monitoring for the real-time stability of seven AAs and 14 acylcarnitines from three levels of 2012 NSQAP QC materials across a time period of 788 days. Arginine suddenly yielded a catastrophic degeneration pattern, which started around D300. When comparing this with previous accelerated degradation studies, methionine, tyrosine, citrulline, and acetylcarnitine did not show a remarkable measurand drift for the real-time stability, except for arginine. Our study showed that arginine would require intensive QC monitoring in routine practice, and should be used for the assessment of the stability in long-term storage of DBS samples for biobanking.

Comparison of test performance of biochemical parameters in semiautomatic method and fully automatic analyzer method

Background

The primary health-care center (PHC) and community health center (CHC) are not well equipped with laboratory services. Semiauto analyzer-based reporting could be an effective modality, provided that the performance standard is comparable to that of the fully automatic analyzer. So, the objective of this study was to analyze the test results of biochemical parameters in semiauto and fully automatic analyzer and to compare the quality performance.

Materials and Methods

One hundred forty-nine patients undergoing routine biochemical investigations in the department laboratory were enrolled in this study. Two millimeter of venous blood was collected from all the participants and processed for urea, cholesterol, triglyceride (TG), serum glutamate-oxaloacetate transaminase (SGOT) (aspartate aminotransferase), and serum glutamate-pyruvate transaminase (SGPT) (alanine aminotransferase) by using standard kits (ERBA) in semiauto analyzer (Transasia Erba Chem5X by Calbiotech Inc. USA, semiautomated clinical chemistry analyzer) and the fully automatic analyzer (Cobas Integra 400 Roche, Germany) method.

Results

There was high variability in the distribution of urea, TG, SGOT, and SGPT values in both measurement methods, whereas cholesterol data followed a normal distribution (skewness: 1.522, 1.037; kurtosis: 2.373, 0.693 in semiauto and automated methods, respectively). A significant positive correlation between both the methods of assessment was observed in urea, cholesterol, TGs, SGOT, and SGPT. The mean difference for urea was -9.85 ± 23.997 (LOA: 37.189, -56.88), whereas it was highest for TG -24.34 ± 38.513 (LOA: 51.144, -99.829), suggesting that both methods can measure urea with less difference in absolute values, whereas for TG the measurement values are highly variable.

Conclusion

The test performance of biochemical parameters such as urea, total cholesterol, TGs, SGOT, and SGPT taken by semiauto analyzer and fully automatic analyzer method of assessment were highly related and comparable.

Performance characteristics of automated clinical chemistry analyzers using commercial assay reagents contributing to quality assurance and clinical decision in a hospital laboratory

Background: Clinical laboratories provide essential diagnostic services that are essential in clinical decision making, contributing to the quality of healthcare. The performance of two Siemens ADVIA 1800 analyzers was characterized in a hospital Biochemistry laboratory in order to evaluate the analytical characteristics of such automated analyzer systems using nonoriginal assay reagents attempting to support laboratory quality service and crucial clinical decision making. Methods: We independently completed performance validation studies including trueness, precision, sensitivity as well as measurement of uncertainty and sigma metrics calculation for 25 biochemical parameters. Results: Trueness expressed as bias was less than 20% for both ADVIA 1800 analyzers. Within run and total precisions expressed as CV% were ≤9.85% on both analyzers for most parameters studied with few exceptions (Mg, TB, DB, Cl, HDL and UA) observed either in low or in high level samples and between the two analyzers. LoB, LoD and LoQ values produced by the two analyzers were comparable except Cl. Uncertainty values produced by the two analyzers were comparable with no significant differences. Quality performance of reagent assays was studied using the sigma metrics system. The sigma values were plotted on normalized method decision charts for graphical representation of assay performances for each analyzer. Conclusions: The two ADVIA systems, independently evaluated, showed consistent performance characteristics with certain discrepancies by several reagents. Sigma analysis was helpful for revealing the quality performance of non-original reagents supporting the need for strict assessment of quality assurance and in some instances optimization/improvement of assay methods.

External Quality Assessment of Glycated Hemoglobin in Iran: Comparison of Five Different Commercial Methods with Two Different Total Allowable Errors

BACKGROUND

Glycated hemoglobin (HbA1c) measuring has a critical role in the monitoring and diagnosis of diabetes. So, the analytical performance of its measuring method must be acceptable. Clinical laboratories should continuously monitor the performance of their commercial methods, both by using proper internal quality control (IQC) and by participating in external quality assessment schemes (EQAS).

METHODS

In January and August 2016, two different freshly prepared commutable patient QC samples were sent to over 1000 laboratories, but 682 and 925 different laboratories which were used five common commercial methods for measuring HbA1c, included in this study during 23th and 24th runs of the external quality assessment program (EQAP), respectively. Target values for total group and also for peer groups were calculated. The performance of each method and laboratory were determined according to two different allowable total errors (TEa), including ±6% and ±20%, which are suggested by the National Glycohemoglobin Standardization Program (NGSP) and Reference Health Laboratory of Iran, respectively.

RESULTS

Considering TEa of ±20% in evaluating HbA1c commercial methods and laboratory performances, pass rates ranged from 97% to 98% during EQAP-23 and EQAP-24, respectively. But when this evaluation was performed according to TEa of ±6%, pass rates decreased significantly to 60% and 62%, respectively.

CONCLUSIONS

Using improper analytical goals has led to misinterpretation of EQA results. In order to maintain the clinical usefulness of HbA1c results, we need to reduce TEa of ±20% to ±6% and improve HbA1c measuring method performance. Although, with TEa of ±6% our pass rates are not so bad.

Irregular analytical errors in diagnostic testing - a novel concept

BACKGROUND

In laboratory medicine, routine periodic analyses for internal and external quality control measurements interpreted by statistical methods are mandatory for batch clearance. Data analysis of these process-oriented measurements allows for insight into random analytical variation and systematic calibration bias over time. However, in such a setting, any individual sample is not under individual quality control. The quality control measurements act only at the batch level. Quantitative or qualitative data derived for many effects and interferences associated with an individual diagnostic sample can compromise any analyte. It is obvious that a process for a quality-control-sample-based approach of quality assurance is not sensitive to such errors.

CONTENT

To address the potential causes and nature of such analytical interference in individual samples more systematically, we suggest the introduction of a new term called the irregular (individual) analytical error. Practically, this term can be applied in any analytical assay that is traceable to a reference measurement system. For an individual sample an irregular analytical error is defined as an inaccuracy (which is the deviation from a reference measurement procedure result) of a test result that is so high it cannot be explained by measurement uncertainty of the utilized routine assay operating within the accepted limitations of the associated process quality control measurements.

SUMMARY

The deviation can be defined as the linear combination of the process measurement uncertainty and the method bias for the reference measurement system. Such errors should be coined irregular analytical errors of the individual sample. The measurement result is compromised either by an irregular effect associated with the individual composition (matrix) of the sample or an individual single sample associated processing error in the analytical process.

OUTLOOK

Currently, the availability of reference measurement procedures is still highly limited, but LC-isotope-dilution mass spectrometry methods are increasingly used for pre-market validation of routine diagnostic assays (these tests also involve substantial sets of clinical validation samples). Based on this definition/terminology, we list recognized causes of irregular analytical error as a risk catalog for clinical chemistry in this article. These issues include reproducible individual analytical errors (e.g. caused by anti-reagent antibodies) and non-reproducible, sporadic errors (e.g. errors due to incorrect pipetting volume due to air bubbles in a sample), which can both lead to inaccurate results and risks for patients.

Increased circulating Tfh17 and PD-1+Tfh cells are associated with autoantibodies in Hashimoto's thyroiditis

OBJECTIVE

Hashimoto's thyroiditis (HT) is characterized by autoantibodies targeting the thyroid. Abnormal CD4⁺CXCR5⁺T cell levels were previously shown to be associated with HT. However, Tfh cells consist of heterogeneous subpopulations, and which T follicular helper (Tfh) cell subpopulation participates in the pathogenesis of HT remains poorly understood.

METHODS

Thirty healthy controls (HCs) and 52 HT patients were enrolled in the study. The percentages of Tfh, ICOS⁺Tfh, PD1⁺Tfh, Tfh1, Tfh2, Tfh17, effector Tfh, resting Tfh, effector memory Tfh, central memory Tfh, and naïve Tfh cells in the peripheral blood were all determined via flow cytometry, and the associations between the percentages of these cells and thyroid function indices were also investigated.

RESULTS

The percentage of Tfh cells was significantly higher in HT patients than in HCs. Examination of the Tfh cell subsets revealed that the percentages of Tfh1, Tfh2, and resting Tfh cells were significantly decreased, while those of the ICOS⁺Tfh, PD1⁺Tfh, Tfh17, and effector Tfh cells were significantly increased in HT patients. No significant differences in effector memory, central memory or naïve Tfh cell percentages were noted between the HC and HT groups. Furthermore, the percentage of PD1⁺Tfh cells was positively correlated with anti-thyroglobulin antibody levels. Most importantly, only Tfh17 cell percentages were positively correlated with anti-thyroglobulin and anti-thyroid peroxidase antibody levels and were negatively correlated serum free T3 and free T4 levels in HT patients.

CONCLUSIONS

Increased circulating Tfh17 cell and PD1⁺Tfh percentages are associated with higher autoantibody levels in HT patients, which imply that Tfh17 or PD1⁺Tfh cells may play a pathogenic role in the development of HT.

Uncertainty of Measurement in Laboratory Medicine

An adequate assessment of the measurement uncertainty in a laboratory medicine is one of the most important factors for a reliable interpretation of the results. A large number of standards and guidelines indicate the need for a proper assessment of the uncertainty of measurement results in routine laboratory practice. The available documents generally recommend participation in the proficiency schemes/ external quality control, as well as the internal quality control, in order to primarily verify the quality performance of the method. Although all documents meet the requirements of the International Standard, ISO 15189, the standard itself does not clearly define the method by which the measurement results need to be assessed and there is no harmonization in practice regarding to this. Also, the uncertainty of measurement results is the data relating to the measured result itself, but all factors that influence the interpretation of the measured value, which is ultimately used for diagnosis and monitoring of the patient's treatment, should be taken into account. So in laboratory medicine, an appropriate assessment of the uncertainty of the measurement results should have the ultimate goal of reducing diagnostic uncertainty. However, good professional laboratory practice and understanding analytical aspects of the test for each individual laboratory is necessary to adequately define the uncertainty of measurement results for specific laboratory tests, which helps to implement good clinical practice. Also, setting diagnoses in medicine is a decision with a certain degree of uncertainty, rather than statistically and mathematically calculated conclusion.

Variants in TPMT, ITPA, ABCC4 and ABCB1 Genes As Predictors of 6-mercaptopurine Induced Toxicity in Children with Acute Lymphoblastic Leukemia

BACKGROUND

Acute lymphoblastic leukemia is the most common childhood malignancy. Optimal use of anti leukemic drugs has led to less toxicity and adverse reactions, and a higher survival rate. Thiopurine drugs, including 6-mercaptopurine, are mostly used as antileukemic medications in the maintenance phase of treatment for children with acute lymphoblastic leukemia. For those patients, TPMT genotype- tailored 6-mercaptopurine therapy is already implemented in the treatment protocols. We investigated the role of TPMT, ITPA, ABCC4 and ABCB1 genetic variants as predictors of outcome and 6-mercaptopurine induced toxicity during the maintenance phase of treatment in pediatric acute lymphoblastic leukemia.

METHODS

Sixty-eight children with acute lymphoblastic leukemia were enrolled in this study. Patients have been treated according to ALL IC-BFM 2002 or ALL IC-BFM 2009 protocols. Toxicity and adverse events have been monitored via surrogate markers (off-therapy weeks, episodes of leu - ko penia and average 6-mercaptopurine dose) and a prob- abilistic model was employed to predict overall 6-mercaptopurine related toxicity.

RESULTS

We confirmed that patients with acute lymphoblastic leukemia that carry inactive TPMT allele(s) require 6- mercaptopurine dose reduction. ITPA and ABCC4 genetic variants failed to show an association with 6-mercapto - purine induced toxicity during the maintenance phase. Carriers of ABCB1 variant allele experienced greater hepatotoxicity. The probabilistic model Neural net which considered all the analysed genetic variants was assessed to be the best prediction model. It was able to discriminate ALL patients with good and poor 6-mercaptopurin tolerance in 71% of cases (AUC=0.71).

CONCLUSIONS

This study contributes to the design of a panel of pharmacogenetic markers for predicting thiopurineinduced toxicity in pediatric ALL.

Effect of Blood Cell Subtypes Lysis on Routine Biochemical Tests

BACKGROUND

The aim of this study is to establish the contribution of blood cells subtypes on hemolysis.

METHODS

Separated blood cell subtype suspensions prepared with blood from 10 volunteers were serially diluted to obtain different concentrations of cell suspensions. The cells were fully lysed and cell hemolysates were added (1:20) to aliquots of serum pool. Thus, seven serum pools with different concentrations of interferent were obtained for each blood cell subtype. Biochemical parameters and serum indices were measured by an autoanalyzer. As cell lysis markers, free hemoglobin was measured by spectrophotometry while myeloperoxidase and ᵝ-thromboglobulin were measured by enzyme immunoassay. The percent changes in analyte levels of the serum pools were evaulated by Wilcoxon Signed Rank Test and compared with clinical thresholds defined for each test.

RESULTS

The clinical thresholds were exceeded in lactate dehydrogenase, potassium, aspartate aminotransferase, creatine kinase, magnesium, total protein, total cholesterol, inorganic phosphate, glucose for red blood cells (RBC); lactate dehydrogenase, aspartate aminotransferase, total protein, inorganic phosphate and glucose for platelets (PLT). Free hemoglobin was significantly correlated with RBC (r=0.999; p=0.001), while myeloperoxidase and b thromboglobulin showed no significant correlation to white blood cells (WBC) and PLT, respectively.

CONCLUSIONS

The effect of RBC hemolysis in serum on the routine biochemical tests are clearly established, yet, additional studies are required in order to verify this kind of effects of PLT and WBC hemolysis.

Is Oxidative Stress Associated with Activation and Pathogenesis of Inflammatory Bowel Disease?

Background

We aimed to determine the levels of total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI) and paraoxonase1/arylesterase levels in inflammatory bowel disease (IBD), and the relation be - tween these molecules and the activity index of the disease.

Methods

Eighty IBD patients (ulcerative colitis (UC)/Crohn disease (CD) 40/40) and 80 control group participants were included in the study. Oxidative stress parameters were measured using the colorimetric method. As disease activity indexes, the endoscopic activity index (EAI) was used for UC and the CD activity index (CDAI) was used for CD.

Results

In IBD patients, mean TAS (1.3±0.2 vs 1.9±0.2, respectively; p<0.001) and arylesterase (963.9±232.2 vs 1252.9±275, respectively; p<0.001) levels were found to be lower and TOS level (5.6±1.6 vs 4.0±1.0, respectively; p<0.001) and OSI rate (4.5±1.6 vs 2.2±0.8, respectively; p<0.001) were found to be higher compared to the control group. A strong positive correlation was found between EAI and TOS levels (r=0.948, p<0.001) and OSI rate (r=0.894, p<0.001) for UC patients. A very strong positive correlation was found between EAI and TOS levels (r=0.964, p<0.001) and OSI rate (r=0.917, p<0.001) for CD patients. It was found in a stepwise regression model that C-reactive protein, OSI and arylesterase risk factors were predictors of IBD compared to the control group. Conclusion: Increased oxidative stress level in IBD patients and the detection of OSI rate as an independent predictor for disease activity indexes lead to the idea that oxidative stress might be related to the pathogenesis of IBD.

The Evaluation of Analytical Performance of Immunoassay Tests by using Six-sigma Method

Background

The Six-Sigma Methodology is a quality measurement method in order to evaluate the performance of the laboratory. In the present study, it is aimed to evaluate the analytical performance of our laboratory by using the internal quality control data of immunoassay tests and by calculating process sigma values.

Methods

Biological variation database (BVD) are used for Total Allowable Error (TEa). Sigma values were determined from coefficient of variation (CV) and bias resulting from Internal Quality Control (IQC) results for 3 subsequent months. If the sigma values are ≥6, between 3 and 6, and <3, they are classified as »world-class«, »good« or »un - acceptable«, respectively.

Results

A sigma value >6 was found for TPSA and TSH for the both levels of IQC for 3 months. When the sigma values were analyzed by calculating the mean of 3 months, folate, LH, PRL, TPSA, TSH and vitamin B12 were found >6. The mean sigma values of CA125, CA15-3, CA19-9, CEA, cortisol, ferritin, FSH, FT3, PTH and testosteron were >3 for 3-months. However, AFP, CA125 and FT4 produced sigma values <3 for varied months.

Conclusion

When the analytical performance was evaluated according to Six-Sigma levels, it was generally found as good. It is possible to determine the test with high error probability by evaluating the fine sigma levels and the tests that must be quarded by a stringent quality control regime. In clinical chemistry laboratories, an appropriate quality control scheduling should be done for each test by using Six-Sigma Methodology.

Novel Opportunities for Improving the Quality of Preanalytical Phase. A Glimpse to the Future?

The preanalytical phase is crucial for assuring the quality of in vitro diagnostics. The leading aspects which contribute to enhance the vulnerability of this part of the total testing process include the lack of standardization of different practices for collecting, managing, transporting and processing biological specimens, the insufficient compliance with available guidelines and the still considerable number of preventable human errors. As in heavy industry, road traffic and aeronautics, technological advancement holds great promise for decreasing the risk of medical and diagnostic errors, thus including those occurring in the extra-analytical phases of the total testing process. The aim of this article is to discuss some potentially useful technological advances, which are not yet routine practice, but may be especially suited for improving the quality of the preanalytical phase in the future. These are mainly represented by introduction of needlewielding robotic phlebotomy devices, active blood tubes, drones for biological samples transportation, innovative approaches for detecting spurious hemolysis and preanalytical errors recording software products.

Laboratory Information System - Where are we Today?

Wider implementation of laboratory information systems (LIS) in clinical laboratories in Serbia has been initiated ten years ago. The first LIS in the Railway Health Care Institute has been implemented nine years ago. Before the LIS was initiated, manual admission procedures limited daily output of patients. Moreover, manual entering of patients data and ordering tests on analyzers was problematic and time consuming. After completing tests, laboratory personnel had to write results in patient register (with potential errors) and provide invoices for health insurance organisation. First LIS brought forward some advantages with regards to these obstacles, but it also showed various weaknesses. These can be summarised in rigidity of system and inability to fulfil user expectation. After 4 years of use, we replaced this system with another LIS. Hence, the main aim of this paper is to evaluate advant ages of using LIS in laboratory of the Railway Health Care Institute and also to discuss further possibilities for its application. After implementing LIS, admission procedure has proven to be much faster. LIS enabled electronic requests, barcoded specimens prevent identification errors, bidirectional interface replaces redundant data entry steps, QC data are transferred automatically, results are electronically validated and automatically archived in data base, billing information is transferred electronically, and more. We also use some advanced options, like delta check, HIL feature, quality indicators and various types of reports. All steps in total testing process are drastically improved after the implementation of LIS, which had a positive impact on the quality of issued laboratory results. However, we expect development of some new features in the future, for example auto-verification and inventory management. On the example of the laboratory of the Railway Health Care Institute, we show that it is crucial that laboratory specialists have the main role in defining desirable characteristics of LIS which institution aims to buy. This paper suggests that the main feature of LIS should be the flexibility of system and capability of adjustment to user needs and requests.

ISO 15189 Accreditation: Navigation Between Quality Management and Patient Safety

Accreditation is a valuable resource for clinical laboratories and the development of an International Standard for their accreditation represented a milestone on the path towards improved quality and safety in laboratory medicine. The recent revision of the International Standard, ISO 15189, has further strengthened its value not only for improving the quality system of a clinical laboratory but also for better answering the request for competence, focus on customers’ needs and ultimate value of laboratory services. Although in some countries more general standards such as ISO 9001 for quality systems or ISO 17025 for testing laboratories are still used, there is increasing recognition of the value of ISO 15189 as the most appropriate and useful standard for the accreditation of medical laboratories. In fact, only this International Standard recognizes the importance of all steps of the total testing process, namely extra-analytical phases, the need to focus on technical competence in addition to quality systems, and the focus on customers’ needs. However, the number of accredited laboratories largely varies between European countries and also major differences affect the approaches to accreditation promoted by the national bodies. In particular, some national accreditation bodies perpetuate the use of fixed scopes, while the European co-operation for accreditation (EA) and the European Federation of Laboratory Medicine (EFLM) Working Group promote the use of flexible scopes. Major issues in clinical laboratory accreditation are the verification of examination procedures for imprecision, trueness and diagnostic accuracy and for estimating measurement uncertainty. In addition, quality indicators (QIs) are a fundamental requirement of the ISO 15189 International Standard.

Accreditation of Medical Laboratories - System, Process, Benefits for Labs

One and key of the priorities in laboratory medicine is improvement of quality management system for patient safety. Quality in the health care is tightly connected to the level of excellence of the health care provided in relation to the current level of knowledge and technical development. Accreditation is an effective way to demonstrate competence of the laboratory, a tool to recognize laboratories world-wide, is linked to periodical audits, to stimulate the maintenance and improvement of the quality, which leads to high standard of services for clients (patients, health care providers, etc.). The strategic plans of IFCC and EFLM include focusing on accreditation of labs based on ISO standards and cooperation with European Accreditation and national accreditation bodies. IFCC and EFLM recognised that ISO 15189:2012 Medical laboratories – Requirements for quality and competence, encompasses all the assessment criteria specified in the policy of quality. The last version is oriented to process approach with detailed division and clearly defined requirements. The accreditation of labs improves facilitation of accurate and rapid diagnostics, efficiency of treatment and reduction of errors in the laboratory process. Accreditation is not about who the best is, but who has a system of standard procedures with aim to improve the quality and patient safety. Quality system is about people, with people and for people.

The Cost-effective Laboratory: Implementation of Economic Evaluation of Laboratory Testing

Laboratory testing as a part of laboratory in vitro diagnostic (IVD) has become required tool in clinical practice for diagnosing, monitoring and prognosis of diseases, as well as for prediction of treatment response. The number of IVD tests available in laboratory practice has increased over the past decades and is likely to further increase in the future. Consequently, there is growing concern about the overutilization of laboratory tests and rising costs for laboratory testing. It is estimated that IVD accounts for between 1.4 and 2.3% of total healthcare expenditure and less than 5% of total hospital cost (Lewin Group report). These costs are rather low when compared to pharmaceuticals and medical aids which account for 15 and 5%, respectively. On the other hand, IVD tests play an important role in clinical practice, as they influence from 60% to 70% of clinical decision-making. Unfortunately, constant increases in healthcare spending are not directly related to healthcare benefit. Since healthcare resources are limited, health payers are interested whether the benefits of IVD tests are actually worth their cost. Many articles have introduced frameworks to assess the economic value of IVD tests. The most appropriate tool for quantitative assessment of their economic value is cost-effectiveness (CEA) and cost-utility (CUA) analysis. The both analysis determine cost in terms of effectiveness or utilities (combine quantity and quality of life) of new laboratory test against its alternative. On the other hand, some investigators recommended calculation of laboratory test value as product of two ratios: Laboratory test value = (Technical accuracy/Turnaround time) × (Utility/Costs). Recently, some researches used multicriteria decision analysis which allows comparison of diagnostic strategies in terms of benefits, opportunities, costs and risks. All analyses are constructed to identify laboratory test that produce the greatest healthcare benefit with the resources available. Without solid evidence that certain laboratory tests are cost-effective, laboratory services cannot be improved. Consequently, simple policy measures such as cost cutting may be imposed upon many laboratories while patients will have limited access to laboratory service.

Laboratory Medicine Management: Leadership Skills for Effective Laboratory

Forum of the European Societies of Clinical Chemistry (FESCC) decided that the FESCC Symposium for Balkan Region would be held each year in Belgrade and organized by the Society of Medical Biochemists of Serbia and Montenegro (SMBSM). Professor Victor Blaton, at the time President of the FESCC, supported the organization of the Symposium. Purpose of these Symposia has been to educate clinical biochemists from Balkan region to improve management, leadership skills for effective laboratories. As a result of these decision twelve symposia have been organized thus far very successfully. Here the most important Symposium topics will be reviewed. Also, the 13^th EFLM Symposium for Balkan Region under the title »Laboratory Medicine Management: Leadership Skills for Effective Laboratory« (Belgrade, September 2017) is organized by EFLM and SMBS under the Auspices of the International Federation of Clinical Chemistry (IFCC), Ministry of Education, Science and Technological Development of Serbia and Ministry of Health of Serbia with participation of the European and domestic specialists in field of Laboratory Medicine.

Laboratory Medicine is Faced with the Evolution of Medical Practice

Laboratory medicine and clinical medicine are co-dependent components of medicine. Laboratory medicine functions most effectively when focused through a clinical lens. Me dical practice as a whole undergoes change. New drugs, treatments and changes in management strategies are introduced. New techniques, new technologies and new tests are developed. These changes may be either clinically or laboratory initiated, and so their introduction requires dialogue and interaction between clinical and laboratory medicine specialists. Treatment monitoring is integral to laboratory medicine, varying from direct drug measurement to monitoring cholesterol levels in response to treatment. The current trend to »personalised medicine« is an extension of this process with the development of companion diagnostics. Technological innovation forms part of modern laboratory practice. Introduction of new technology both facilitates standard laboratory approaches and permits introduction of new tests and testing strategies previously confined to the research laboratory only. The revolution in cardiac biomarker testing has been largely a laboratory led change. Flexibility in service provision in response to changing clinical practice or evolving technology provides a significant laboratory management challenge in the light of increasing expectations, shifts in population demographics and constraint in resource availability. Laboratory medicine practitioners are adept at meeting these challenges. One thing remains constant, that there will be a constant need laboratory medicine to meet the challenges of novel clinical challenges from infectious diseases to medical conditions developing from lifestyle and longevity.

Procalcitonin and CRP as Biomarkers in Discrimination of Community-acquired Pneumonia and Exacerbation of COPD

Background

Serum procalcitonin (PCT) and C-reactive protein (CRP) are markers of systemic inflammation and bacterial infection. We aimed to compare the usefulness of procalcitonin and CRP in patients with community-acquired pneumonia and exacerbations of chronic obstructive pulmonary disease (COPD).

Methods

A total of 116 consecutive patients were included in the study: 76 with chronic obstructive pulmonary disease in group 1, and 40 with pneumonia in group 2.

Results

Median serum CRP level was 44 mg/L in the COPD group and 132 mg/L in the pneumonia group. Median value of serum PCT was found to be 0.07 in the COPD group and 0.14 ng/mL in the pneumonia group. Serum PCT and CRP levels were significantly higher in the pneumonia group compared to the COPD group (p<0.001). The area under the ROC curve was 0.788 (CI: 0.704–0.872) for CRP and 0.699 (CI: 0.599–0.800) for procalcitonin to identify pneumonia.

Conclusions

Procalcitonin and CRP levels were significantly higher in patients with community-acquired pneumonia presenting to the emergency department with indications for hospitalization than in patients with exacerbations of chronic obstructive pulmonary disease. Serum CRP and procalcitonin concentrations were strongly correlated. CRP might be a more valuable marker in these patients with lower respiratory tract infections.

Medical Biochemistry as Subdiscipline of Laboratory Medicine in Serbia

Medical biochemistry is the usual name for clinical biochemistry or clinical chemistry in Serbia, and medical biochemist is the official name for the clinical chemist (or clinical biochemist). This is the largest sub-discipline of the laboratory medicine in Serbia. It includes all aspects of clinical chemistry, and also laboratory hematology with coagulation, immunology, etc. Medical biochemistry laboratories in Serbia and medical biochemists as a profession are part of Health Care System and their activities are regulated through: the Health Care Law and rules issued by the Chamber of Medical Biochemists of Serbia. The first continuous and organized education for Medical Biochemists (Clinical Chemists) in Serbia dates from 1945, when the Department of Medical Biochemistry was established at the Pharmaceutical Faculty in Belgrade. In 1987 at the same Faculty a five years undergraduate study program was established, educating Medical Biochemists under a special program. Since the academic year 2006/2007 the new five year undergraduate (according to Bologna Declaration) and four-year postgraduate program according to EC4 European Syllabus for Postgraduate Training in Clinical Chemistry and Laboratory Medicine has been established. The Ministry of Education and Ministry of Public Health accredited these programs. There are four requirements for practicing medical biochemistry in the Health Care System: University Diploma of the Faculty of Pharmacy (Study of Medical Biochemistry), successful completion of the professional exam at the Ministry of Health after completion of one additional year of obligatory practical training in the medical biochemistry laboratories, membership in the Serbian Chamber of Medical Biochemists and licence for skilled work issued by the Serbian Chamber of Medical Biochemists. In order to present laboratory medical biochemistry practice in Serbia this paper will be focused on the following: Serbian national legislation, healthcare services organization, sub-disciplines of laboratory medicine and medical biochemistry as the most significant, education in medical biochemistry, conditions for professional practice in medical biochemistry, continuous quality improvement, and accreditation. Serbian healthcare is based on fundamental principles of universal health coverage and solidarity between all citizens.

An LC-MS Assay with Isocratic Separation and On-line Solid Phase Extraction to Improve the Routine Therapeutic Drug Monitoring of Busulfan in Plasma

Background

Busulfan (Bu) requires therapeutic drug monitoring (TDM) in subjects undergoing a conditioning regimen for hematopoietic stem cell transplantation (HSCT). To speed up the procedure and increase reproducibility, we improved our routine LC-MS/MS assay using the on-line solid-phase extraction (SPE) of samples.

Methods

A protein precipitation (PP) step was performed before the on-line SPE of Bu from 200 µL of plasma spiked with octa-deuterated Bu (D8-Bu) as the internal standard. Bias was assessed with respect to our routine LC-MS/MS Bu assay with off-line extraction using the Passing-Bablok robust regression. Root cause of bias for individual samples was assessed by analyzing the regression residuals.

Results

The method was linear in the range 37.75–2,416 ng/mL (r2>0.999), with 19.74 ng/mL LLOQ and 10.5% CV at 20 ng/mL. Precision and accuracy were both within ±5%, and neither appreciable matrix nor carryover effects were observed. The Passing-Bablok regression analysis returned a 0.99 slope (95% CI: 0.97 to 1.01) and –6.82 intercept (95% CI: –15.23 to 3.53). Residuals analysis against the 2.5th–97.5th percentiles range showed four samples with significant bias individually.

Conclusions

The method presented can be successfully employed for the routine analysis of Bu in plasmatic samples, and can replace the LC-MS/MS method with off-line extraction without any statistically significant overall bias. In this regard, samples with individual significant bias were reasonably produced by preanalytical issues which had no relation with the conversion to the on-line SPE extraction.

The Role of Red Blood Cell Distribution Width for Predicting 1-year Mortality in Patients Admitted to the Emergency Department with Severe Dyspnoea

BACKGROUND

Universally accepted and validated instruments for predicting the outcome of patients presenting to the emergency department (ED) with severe dyspnoea do not exist so far, nor are they regularly used by the emergency physicians. This study hence aimed to establish whether red blood cell distribution width (RDW) may be a predictive parameter of 1-year mortality in a population of patients admitted to the ED with severe dyspnoea attributable to different underlying disorders.

METHODS

We retrospectively evaluated all the patients undergoing arterial blood gas analysis for severe dyspnoea (irrespective of the cause) during admission to ED of University Hospital of Verona from September 1, 2014 to November 31, 2014.

RESULTS

The final study population consisted of 287 patients for whom complete clinical and laboratory information was available. Overall, 36 patients (12.5%) died after a 1-year follow-up. The RDW value was found to be considerably increased in patients who deceased during the follow-up compared to those who survived (17.2% versus 14.8%; p<0.001). In both univariate and multivariate analyses, the RDW value was found to be a significant predictor of 1-year mortality. In particular, patients with RDW ≥ 15.0% displayed a 72% increased risk of 1-year mortality after multiple adjustments.

CONCLUSIONS

The measurement of RDW, a very simple and inexpensive laboratory parameter, may represent an important factor for predicting medium-term mortality in patients presenting to the ED with severe dyspnoea.