Laboratory medicine in arterial hypertension.

In the initial diagnostics of arterial hypertension (AH) laboratory medicine is a cornerstone, along with a blood pressure (BP) measurement and an electrocardiogram. It mainly refers to routine blood and urine tests for diagnosis and monitoring primary hypertension and its associated conditions such as asymptomatic hypertension-mediated organ damage, chronic kidney disease and hypertensive disorders of pregnancy. In addition, long term non-fatal and fatal risks for cardiovascular (CV) events in hypertension are assessed based on clinical and laboratory data. Furthermore, laboratory medicine is involved in the management of hypertension, especially in monitoring the disease progression. However, antihypertensive drugs may interfere with laboratory test results. Diuretics, especially thiazides, can affect blood and urine sodium concentrations, or angiotensin-converting enzyme inhibitors and angiotensin receptor blockers can affect the blood biomarkers of the renin-angiotensin-aldosterone system (RAAS). It's dysfunction plays a critical role in primary aldosteronism (PA), the most common endocrine disorder in secondary hypertension, which accounts for only small proportion of AH in relative terms but substantial proportion of hypertensives in absolute terms, affecting younger population and carrying a higher risk of CV mortality and morbidity. When screening for PA, aldosterone-to-renin ratio still contributes massively to the increased incidence of the disease, despite certain limits. In conclusion, laboratory medicine is involved in the screening, diagnosis, monitoring and prognosis of hypertension. It is of great importance to understand the preanalytical and analytical factors influencing final laboratory result.

Serum bicarbonate stability study at room temperature - influence of time to centrifugation and air exposure on bicarbonate measurement reported according to the CRESS checklist.

OBJECTIVES: The aim was to evaluate the stability of serum bicarbonate at room temperature, depending on time to centrifugation and air exposure. METHODS: Stability study was conducted in the laboratory of Clinical Hospital Centre Rijeka, Croatia in January-February 2022. Nine samples from 10 volunteers were collected in clot activator gel tubes (Greiner Bio-One). Bicarbonate was measured on Beckman Coulter AU480 (Beckman Coulter, Brea, USA). Three tubes were left at room temperature for 30 min, three tubes for 2 h, three tubes for 4 h until centrifugation. First tube from first group (baseline) was measured immediately after centrifugation. Other measurements were expressed as percentage deviation (PD%) from baseline. First tube was remeasured after 1 and 2 h (OT_0h_1h; OT_0h_2h). Second and third tubes were opened 1 and 2 h after centrifugation (C_0h_1h; C_0h_2h). Second group of tubes was processed the same way with 2-hour centrifugation delay (WB_2h; OT_2h_1h; OT_2h_2h; C_2h_1h; C_2h_2h), and third group with 4-hour delay (WB_4h; OT_4h_1h; OT_4h_2h; C_4h_1h; C_4h_2h). PD% was compared to Maximum Permissible Difference (MPD=5.69%). MedCalc statistical software was used (MedCalc, Ostend, Belgium). RESULTS: Bicarbonate baseline mean value (range) was 27.3 (23.4-29.6) mmol/L. Obtained PD% (95%CI) were: C_0h_1h 0.46 (-1.21, 2.12); C_0h_2h 0.18 (-2.22, 2.57); OT_0h_1h -6.46 (-7.57, -5.36); OT_0h_2h -10.67 (-12.13, -9.21); WB_2h -0.15 (-2.04, 1.74); C_2h_1h 0.01 (-1.52, 1.54); C_2h_2h -0.40 (-2.65, 1.85); OT_2h_1h -5.43 (-7.30, -3.55); OT_2h_2h -11.32 (-13.57, -9.07); WB_4h -0.85 (-3.28, 1.58); C_4h_1h -2.52 (-4.93, 0.11); C_4h_2h -3.02 (-5.62, 0.43); OT_4h_1h -7.34 (-9.64, -5.05); OT_4h_2h -11.85 (-14.38, -9.33). CONCLUSIONS: Serum bicarbonate is stable for 4 h in closed uncentrifuged tubes, another 2 h in closed tubes after centrifugation, and is unstable within 1 h in opened tube.

An analysis of the vitamin D overtesting in a tertiary healthcare centre.

Introduction: Vitamin D testing is excessively used in clinical practice, despite of the clinical guidelines statements against population screening for vitamin D deficiency. This study aimed to assess an annual number of performed 25-hydroxy vitamin D (25(OH)D) tests that were unsupported by the national guidelines for prevention, detection and therapy of vitamin D deficiency in adults and to calculate associated financial burden for the publicly funded healthcare. Materials and methods: A representative sample of requested 25(OH)D tests in 2018 (N = 474) was formed after selection and randomisation of data set (N = 5298) collected from the laboratory information system database of the Clinical Department for Laboratory Diagnostics, the Clinical Hospital Centre Rijeka. Records were classified in two groups depending on associated medical condition(s) according to the national guidelines. An annual cost of the total and group specific vitamin D testing was calculated on the base of a single test price reimbursed by the Croatian Healthcare Insurance Fund (CHIF). Results: Medical conditions with high-risk for vitamin D deficiency were detected in 43% (206/474) of vitamin D requests (group 1). Conditions not associated with vitamin D deficiency were detected in 57% (268/474) requests (group 2). A total cost of 25(OH)D testing for the CHIF was 58,729.50 EUR (25,523.79 EUR in the group 1 and 33,205.71 EUR in the group 2). Conclusions: More than half of all 25(OH)D tests performed in the clinical laboratory represent avoidable cost for the public healthcare. Prevention of population screening by vitamin D testing is needed.

Comparison of three different protocols for obtaining hemolysis.

OBJECTIVES: Hemolysis is associated with erroneous or delayed results. Objectives of the study were to compare four different methods for obtaining hemolysis in vitro on three different analyzers. METHODS: Hemolysis was prepared with addition of pure hemoglobin into serum pool, osmotic shock, aspiration through blood collection needle, freezing/thawing of whole blood. Biochemistry parameters were measured in duplicate at Architect c8000 (Abbott, Abbott Park, USA), Beckman Coulter AU680 (Beckman Coulter, Brea, USA) and Cobas 6000 c501 (Roche, Mannheim, Germany), according to manufacturers' declarations. Cut-off value was defined as the highest value of H index with corresponding bias lower than acceptance criteria. RESULTS: We were not able to obtain results with freezing protocol. On all three platforms, lowest number of analytes were sensitive to hemolysis at H=0.5 using method of adding free hemoglobin. When osmotic shock was used, cut-off values for the most analytes were generally met at lower values. Hemolysis significantly interfered with measurement of potassium and lactate dehydrogenase (LD) at H=0.5 on all platforms. The most of the tested analytes had the lowest acceptable H index when aspiration method was used. At the low level of hemolysis (H=0.8) glucose, sodium, potassium, chloride, phosphate, and LD were affected on all analyzers, with some additional analytes depending on the manufacturer. CONCLUSIONS: Hemolysis interference differs on different analyzers and according to protocol for obtaining hemolysis. Aspiration method was generally the most sensitive to hemolysis interference, while addition of free Hb was the most resistant.

Copyright violation of predators in scientific publishing - Biochemia Medica's harmful experience and proposed solution.

Biochemia Medica is an open access journal that does not charge manuscript processing or publishing. All editorial staff are continuously educated and directed to follow the highest ethical and scholarly publishing standards in all steps of the manuscript processing. They are all laboratory medicine professionals, who apart from their regular jobs, are in charge of different phases in Journal processing as volunteers. The publisher of the Journal is scientific and professional association of laboratory medicine professionals, Croatian Society of Medical Biochemistry and Laboratory medicine (CSMBLM). During November and December 2018, without knowledge of the editorial staff, unknown perpetrator(s) downloaded a respectable number of articles published in Biochemia Medica as PDF and launched an illegal web page under the same journal name with downloaded articles. Although this was a very harmful experience, we have learned a lot from it and we would like to share this with scientific journals' community. Therefore, we would like to share this harmful experience, and to present a short workflow on how to manage situations like this if it will be necessary for any scientific journal in the future.

INFORMED CONSENT IN CROATIAN CLINICAL LABORATORY PRACTICE - CURRENT ISSUES AND FUTURE PERSPECTIVES.

This paper deliberates on the place and role of informed consent in everyday clinical laboratory practice. Taking into account international ethical guidelines such as the UNESCO Universal Declaration on Bioethics and Human Rights, the Declaration of Helsinki of the World Medical Association, and Croatian national laws and codes such as the Act on the Protection of Patients' Rights, the Act on Medical Biochemistry, the Code of Ethics of Medical Biochemists and Medical Deontology, the Act on Healthcare Services, and the Code of Ethics of the Croatian Chamber of Healthcare Workers, an overview is given on the actual implementation of the aforementioned recommendations and regulations. A distinction between consent to a medical procedure and consent to enrolment in a research protocol is strongly stressed out. Special emphasis is placed on the role of specialists in laboratory medicine and masters of medical biochemistry in the process of obtaining informed consent. The design of an 'informed consent interview' is to be taken into consideration. Additional deliberation is needed on the option of 'broad consent'. It is concluded that informed consent should represent an important and routine activity within Croatian clinical laboratories.

Informed consent and ethics committee approval in laboratory medicine.

Informed consent is a process in which a human subject who is to participate in research needs to give his or her consent after being properly informed of the expected benefits as well as the potential harm of the research that will be performed. The function and purpose of the research ethics committee is to ensure that the research that will take place is in accordance with the relevant ethical standards. This means that the committee must assess the appropriateness of the design of the study reviewed. Research in the field of laboratory medicine has specific features, i.e. the use of samples that remain after routine analysis, data collection from databases containing patient information, data mining, collection of laboratory management data, method/instrument comparisons and validation, etc. As most of such research is either retrospective or not directly associated with patients, the question arises as to whether all types of research require informed consent and ethics committee approval. This article aims to clarify what is specific about obtaining informed consent and ethical approval in laboratory medicine, to provide general guidance on informed consent and ethical approval requirements based on the type of study, and what information should be included in applications for ethical approval and informed consent. This could also provide some guidance for future contributors to the Biochemia Medica.

Precision, accuracy, cross reactivity and comparability of serum indices measurement on Abbott Architect c8000, Beckman Coulter AU5800 and Roche Cobas 6000 c501 clinical chemistry analyzers.

BACKGROUND: The aim of our study was to perform verification of serum indices on three clinical chemistry platforms. METHODS: This study was done on three analyzers: Abbott Architect c8000, Beckman Coulter AU5800 (BC) and Roche Cobas 6000 c501. The following analytical specifications were verified: precision (two patient samples), accuracy (sample with the highest concentration of interferent was serially diluted and measured values compared to theoretical values), comparability (120 patients samples) and cross reactivity (samples with increasing concentrations of interferent were divided in two aliquots and remaining interferents were added in each aliquot. Measurements were done before and after adding interferents). RESULTS: Best results for precision were obtained for the H index (0.72%-2.08%). Accuracy for the H index was acceptable for Cobas and BC, while on Architect, deviations in the high concentration range were observed (y=0.02 [0.01-0.07]+1.07 [1.06-1.08]x). All three analyzers showed acceptable results in evaluating accuracy of L index and unacceptable results for I index. The H index was comparable between BC and both, Architect (Cohen's κ [95% CI]=0.795 [0.692-0.898]) and Roche (Cohen's κ [95% CI]=0.825 [0.729-0.922]), while Roche and Architect were not comparable. The I index was not comparable between all analyzer combinations, while the L index was only comparable between Abbott and BC. Cross reactivity analysis mostly showed that serum indices measurement is affected when a combination of interferences is present. CONCLUSIONS: There is heterogeneity between analyzers in the hemolysis, icteria, lipemia (HIL) quality performance. Verification of serum indices in routine work is necessary to establish analytical specifications.

Dealing with the positive publication bias: Why you should really publish your negative results.

Studies with positive results are greatly more represented in literature than studies with negative results, producing so-called publication bias. This review aims to discuss occurring problems around negative results and to emphasize the importance of reporting negative results. Underreporting of negative results introduces bias into meta-analysis, which consequently misinforms researchers, doctors and policymakers. More resources are potentially wasted on already disputed research that remains unpublished and therefore unavailable to the scientific community. Ethical obligations need to be considered when reporting results of studies on human subjects as people have exposed themselves to risk with the assurance that the study is performed to benefit others. Some studies disprove the common conception that journal editors preferably publish positive findings, which are considered as more citable. Therefore, all stakeholders, but especially researchers, need to be conscious of disseminating negative and positive findings alike.

An Analysis of Medical Laboratory Technology Journals' Instructions for Authors.

Instructions for authors (IFA) need to be informative and regularly updated. We hypothesized that journals with a higher impact factor (IF) have more comprehensive IFA. The aim of the study was to examine whether IFA of journals indexed in the Journal Citation Reports 2013, "Medical Laboratory Technology" category, are written in accordance with the latest recommendations and whether the quality of instructions correlates with the journals' IF. 6 out of 31 journals indexed in "Medical Laboratory Technology" category were excluded (unsuitable or unavailable instructions). The remaining 25 journals were scored based on a set of 41 yes/no questions (score 1/0) and divided into four groups (editorial policy, research ethics, research integrity, manuscript preparation) by three authors independently (max score = 41). We tested the correlation between IF and total score and the difference between scores in separate question groups. The median total score was 26 (21-30) [portion of positive answers 0.63 (0.51-0.73)]. There was no statistically significant correlation between a journal's IF and the total score (rho = 0.291, P = 0.159). IFA included recommendations concerning research ethics and manuscript preparation more extensively than recommendations concerning editorial policy and research integrity (Ht = 15.91, P = 0.003). Some policies were poorly described (portion of positive answers), for example: procedure for author's appeal (0.04), editorial submissions (0.08), appointed body for research integrity issues (0.08). The IF of the "Medical Laboratory Technology" journals does not reflect a journals' compliance to uniform standards. There is a need for improving editorial policies and the policies on research integrity.

Biochemia Medica's editorial policy on authorship.

Recent findings of authorship criteria violations in the manuscripts submitted to Biochemia Medica show that almost 40% of authors do not meet necessary criteria for authorship and thus indicate the need for better dissemination of editorial policy on authorship in our journal. We believe that such cases are mostly due to the authors' unawareness or the lack of understanding of the authorship criteria. With this article we therefore wish to declare our editorial policy on authorship and authorship criteria. Biochemia Medica endorses the authorship policy provided by the International Committee of Medical Journal Editors (ICMJE). Information on authorship is assessed by self-reported authorship claims during on-line manuscript submission. Those who meet ICMJE criteria shall be listed as authors, and all listed authors shall fulfill ICMJE criteria. All authors should be responsible for content of the article and have to know other authors' contributions to the study. Biochemia Medica will follow recommendations provided by Committee on Publication Ethics (COPE) flowcharts for possible disputes. By adhering to this procedure we hope to raise awareness about the importance of compliance with ICMJE authorship recommendations.

ICMJE authorship criteria are not met in a substantial proportion of manuscripts submitted to Biochemia Medica.

INTRODUCTION: Our aim was to investigate if: (a) authors of Biochemia Medica meet authorship criteria given by International Committee of Medical Journal Editors (ICMJE), (b) authorship violations are more frequent in submissions containing some type of scientific misconduct. MATERIALS AND METHODS: Self-reported authorship contributions regarding the three ICMJE criteria were analysed for all submissions to Biochemia Medica (February 2013-April 2015) which were forwarded to peer-review. To test the differences in frequencies we used Chi-squared test. P<0.05 was considered statistically significant. RESULTS: 186 manuscripts were authored by 804 authors. All ICMJE criteria were met by 487/804 (61%) authors. The first and the last author met all the criteria more frequently than those authors in between (P<0.001). The degree to which ICMJE criteria was met for the first author did not differ between manuscripts authored by only one author and those authored by >1 author (P=0.859). In 9% of the manuscripts ICMJE criteria were not met by a single author. Authors of the 171/186 manuscripts declared that all persons qualify for authorship but only 49% of them satisfied all ICMJE criteria. Authors have failed to acknowledge contributors in 88/186 (47%) manuscripts; instead these contributors have been listed as authors without fulfilling ICMJE criteria. Authorship violation was not more common in 42 manuscripts with some type of scientific misconduct (P=0.135). CONCLUSION: Large proportion of authors of the manuscripts submitted to Biochemia Medica do not fulfil ICMJE criteria. Violation of authorship criteria is not more common for manuscripts with some type of scientific misconduct.

Influence of a prolonged fasting and mild activity on routine laboratory tests.

OBJECTIVES: Despite the standardization of the phlebotomy procedure, blood analysis is occasionally requested after recommended hours with the excuse that the patient is still fasting. We aimed to examine the influence of prolonged fasting and mild physical activity on routine laboratory tests. DESIGN AND METHODS: The study was conducted on 30 volunteers (27 female) median age 40y (20-59). Blood samples were taken in the morning (7:00-8:00a.m.) and early afternoon (1:00-2:00p.m.) after prolonged fasting and usual daily activities. Serum glucose (GLU), urea, creatinine, triglyceride, uric acid (UA), iron and electrolytes were analyzed on Roche cobas 6000 c501 and complete blood count on Siemens ADVIA 2120i. Statistical significance between the two measurements was tested using paired t-test or Wilcoxon test according to data distribution. Clinical significance was judged against calculated reference change values (RCV). RESULTS: A statistically significant decrease was found for red blood cell count, hemoglobin, hematocrit, mean corpuscular volume (MCV), GLU, urea, creatinine, triglycerides and electrolytes, whereas white blood cell count and iron were significantly increased. Judging against desirable bias derived from biological variation, a significant change was found for all the analytes except MCV, platelet count, UA and triglycerides. A clinically significant change was not found for any of the tested analytes when compared to RCV. CONCLUSIONS: Prolonged fasting and mild activity will not influence the medical decision for healthy subjects with normal results. Despite the present statistically significant change, the clinically significant change was not shown. However, the study did not include pathological results which have to be interpreted more carefully.

Salami publication: definitions and examples.

Salami publication or segmented publication is a distinct form of redundant publication which is usually characterized by similarity of hypothesis, methodology or results but not text similarity. These aspects of publications are not objectively detected by software applications and therefore present a serious threat to publication ethics. This article presents a practical approach for dealing with manuscripts suspected of salami publication during the submission process and after article publication in Biochemia Medica.

Croatian Society of Medical Biochemistry and Laboratory Medicine: national recommendations for venous blood sampling.

Phlebotomy is one of the most complex medical procedures in the diagnosis, management and treatment of patients in healthcare. Since laboratory test results are the basis for a large proportion (60-80%) of medical decisions, any error in the phlebotomy process could have serious consequences. In order to minimize the possibility of errors, phlebotomy procedures should be standardised, well-documented and written instructions should be available at every workstation. Croatia is one of the few European countries that have national guidelines for phlebotomy, besides the universally used CLSI (Clinical Laboratory Standards Institute) H3-A6 Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture; approved Standard-Sixth Edition (CLSI, 2007) and WHO (World Health Organization) guidelines on drawing blood: best practices in phlebotomy (WHO, 2010). However, the growing body of evidence in importance of preanalytical phase management resulted in a need for evidence based revision and expansion of existing recommendations. The Croatian Society for Medical Biochemistry and Laboratory Medicine, Working Group for the Preanalytical Phase issued this recommendation. This document is based on the CLSI guideline H3-A6, with significant differences and additional information.

Biochemia Medica has started using the CrossCheck plagiarism detection software powered by iThenticate.

In February 2013, Biodhemia Medica has joined CrossRef, which enabled us to implement CrossCheck plagiarism detection service. Therefore, all manuscript submitted to Biodchemia Medica are now first assigned to Research integrity editor (RIE), before sending the manuscript for peer-review. RIE submits the text to CrossCheck analysis and is responsible for reviewing the results of the text similarity analysis. Based on the CrossCheck analysis results, RIE subsequently provides a recommendation to the Editor-in-chief (EIC) on whether the manuscript should be forwarded to peer-review, corrected for suspected parts prior to peer-review or immediately rejected. Final decision on the manuscript is, however, with the EIC. We hope that our new policy and manuscript processing algorithm will help us to further increase the overall quality of our Journal.

Patchwork plagiarism--a jigsaw of stolen puzzle pieces.

Plagiarism remains at the top in terms of interest to the scientific community. In its many vicious forms, patchwork plagiarism is characterized by numerous unresolved issues and often passes "below the radar" of editors and reviewers. The problem of detecting the complexity of misconduct has been partially resolved by plagiarism detection software. However, interpretation of relevant reports is not always obvious or easy. This article deals with plagiarism in general and patchwork plagiarism in particular, as well as related problems that editors must deal with to maintain the integrity of scientific journals.

Validation of methods performance for routine biochemistry analytes at Cobas 6000 analyzer series module c501.

INTRODUCTION: Cobas 6000 (Roche, Germany) is biochemistry analyzer for spectrophotometric, immunoturbidimetric and ion-selective determination of biochemical analytes. Hereby we present analytical validation with emphasis on method performance judgment for routine operation. MATERIALS AND METHODS: Validation was made for 30 analytes (metabolites, enzymes, trace elements, specific proteins and electrolytes). Research included determination of within-run (N = 20) and between-run imprecision (N = 30), inaccuracy (N = 30) and method comparison with routine analyzer (Beckman Coulter AU640) (N = 50). For validation of complete analytical process we calculated total error (TE). Results were judged according to quality specification criteria given by European Working Group. RESULTS: Within-run imprecision CVs were all below 5% except for cholesterol, triglycerides, IgA and IgM. Between-run CVs for all analytes were below 10%. Analytes that did not meet the required specifications for imprecision were: total protein, albumin, calcium, sodium, chloride, immunoglobulins and HDL cholesterol. Analytes that did not fulfill requirements for inaccuracy were: total protein, calcium, sodium and chloride. Analytes that deviated from quality specifications for total error were: total protein, albumin, calcium, sodium, chloride and IgM. Passing-Bablok regression analysis provided linear equation and 95% confidence interval for intercept and slope. Complete accordance with routine analyzer Beckman Coulter AU640 showed small number of analytes. Other analytes showed small proportional and/or small constant difference and therefore need to be adjusted for routine operation. CONCLUSIONS: Regarding low CV values, tested analyzer has satisfactory accuracy and precision and is extremely stable. Except for analytes that are coherent on both analyzers, some analytes require adjustments of slope and intercept for complete accordance.