Critical review of laboratory investigations in clinical practice guidelines: proposals for the description of investigation

An improved implementation of metrological traceability concepts is needed to benefit from standardization of laboratory results

Non-harmonization of laboratory results represents a concrete risk for patient safety. To avoid harms, it is agreed that measurements by in vitro diagnostic medical devices (IVD-MD) on clinical samples should be traceable to higher-order references and adjusted to give the same result. However, metrological traceability is not a formal claim and has to be correctly implemented, which in practice does not happen for a non-negligible number of measurands. Stakeholders, such as higher-order reference providers, IVD manufacturers, and External Quality Assessment organizers, have major responsibilities and should improve their contribution by unambiguously and rigorously applying what is described in the International Organization for Standardization 17511:2020 standard and other documents provided by the international scientific bodies, such as Joint Committee on Traceability in Laboratory Medicine and IFCC. For their part, laboratory professionals should take responsibility to abandon non-selective methods and move to IVD-MDs displaying proper selectivity, which is one of the indispensable prerequisites for the correct implementation of metrological traceability. The practicality of metrological traceability concepts is not impossible but relevant education and appropriate training of all involved stakeholders are essential to obtain the expected benefits in terms of standardization.

Assessment of hematology laboratory performance in the total testing process using quality indicators and sigma metrics in the northwest of Ethiopia: A cross-sectional study

Background and Aims

Assuring laboratory quality by minimizing the magnitude of errors is essential. Therefore, this study aimed to assess hematology laboratory performance in the total testing process using quality indicators and sigma metrics.

Methods

A cross-sectional study was conducted from April to June 2022. The study included a total of 13,546 samples. Data on included variables were collected using a checklist. Descriptive statistics were used to present the overall distribution of errors. Binary logistic regression models were applied. Furthermore, using a Sigma scale, the percentage of errors was converted to defects per million opportunities to assess laboratory performance. Finally, the defect per million opportunities was converted to a sigma value using a sigma calculator.

Results

Of the 13,546 samples and corresponding requests, the overall error rate was 123,296/474,234 (26%): 93,412/47,234 (19.7%) pre-analytical, 2364/474,234 (0.5%) analytical, and 27,520/474,234 (5.8%) post-analytical. Of the overall errors, 93,412/123,296 (75.8%), 2364/123,296 (1.9%), and 27,520/123,296 (22.3%) were pre-analytical, analytical, and post-analytical errors, respectively. The overall sigma value of the laboratory was 2.2. The sigma values of the pre-analytical, analytical, and post-analytical phases were 2.4, 4.1, and 3.1, respectively. The sample from the inpatient department and collected without adherence to the standard operating procedures (SOPs) had a significantly higher (p < 0.05) rejection rate as compared to the outpatient department and collected with adherence to SOPs, respectively. In addition, an association between prolonged turnaround times and manual recording, inpatient departments, and morning work shifts was observed.

Conclusion

The current study found that the overall performance of the laboratory was very poor (less than three sigma). Therefore, the hospital leadership should change the manual system of ordering tests and release of results to a computerized system and give need-based training for all professionals involved in hematology laboratory sample collection and processing.

Reference intervals of the sex hormonal profile in healthy women: A retrospective single-center study in Peru

The female hormonal profile is of utmost importance for the assessment of the endocrinological functional status and the diagnosis of diseases. The analysis must delimit their normality intervals based on the manufacturer's cut-off points. Due to not all intervals can be evaluated before use, it is imperative to verify the reference intervals to achieve uniformity in the interpretation of results in the female population. We determine the reference intervals of five female sex hormones [Follicle Stimulating hormone (FSH), Estradiol, Luteinizing Hormone (LH), Prolactin, and progesterone] using electrochemiluminescence in the Cobas e411 (Roche). We included female patients >18 years old, between the 3rd and 15th day of the menstrual cycle (follicular phase) and had no previous medical history or recent medication. For reference intervals analysis, we followed the recommendations of the CLSI C28-A3 guideline. The average concentration for FSH, progesterone, LH, prolactin and estradiol were 11.48 ± 21.10 mIU/ml, 8.19 ± 11.90 ng/ml, 10.98 ± 11.55 ng/ml, 25.05 ± 32.74 ng/mL, and 147.08 ± 473.8 pmol/mL, respectively. Eighty per cent of parameters showed a satisfactory transfer for the manufacturer's reference intervals, except for estradiol, which had 85.5% of transferred values. Our results suggest that 4/5 sex hormones were found within the manufacturer's reference intervals and can be quantified in Peruvian women, ensuring the quality of their results. However, it is necessary to determine the estradiol with other reagents and assays since we show errors in the transfer of intervals.

2021 update of the 2012 ICSH Recommendations for identification, diagnostic value, and quantitation of schistocytes: Impact and revisions

In 2012, the International Council for Standardization in Hematology (ICSH) published recommendations for the identification, quantitation, and diagnostic value of schistocytes. In the present review, the impact of these recommendations is evaluated. This work is based on citations in peer-reviewed papers published since 2012. The first 2012 ICSH Recommendations have also been revised to incorporate newly published data in the literature and current best laboratory practice. Recommended reference ranges have been proposed for healthy adults and full-term neonates of 1% or less schistocytes. More than 1% of morphologically identified schistocytes on the blood film are considered suspicious for thrombotic microangiopathy. For preterm infants, a normal level of 5% or less is recommended. The fragment red cell count (FRC) generated by some automated hematological analyzers provides a valuable screening tool for the presence of schistocytes. Specifically, the absence of FRCs can be used as a valuable parameter to exclude the presence of schistocytes on the blood film. The validity and usefulness of microscope schistocytes and automated FRCs, respectively, are discussed in the context of the laboratory diagnostic tests used for thrombotic microangiopathies.

An opportunity to emphasize the relevance of laboratory medicine

Objectives

Clinical practice guidelines (CPGs) are recommendations based on a systematic review of scientific evidence that are intended to help healthcare professionals and patients make the best clinical decisions. CPGs must be evidence-based and are designed by multidisciplinary teams. The purpose of this study is to assess the topics related to the clinical laboratory addressed in CPGs and evaluate the involvement of laboratory professionals in the CPG development process.

Methods

A total of 16 CPGs recommended by the Spanish Society of Laboratory Medicine and/or retrieved from PubMed-Medline were included. A review of the information provided in CPGs about 80 topics related to the clinical laboratory was performed. The authorship of laboratory professionals was assessed.

Results

On average, the 16 CPGs addressed 49% (standard deviation [SD]: 11%) of the topics evaluated in relation to the clinical laboratory. By order of frequency, CPGs contained information about 69% of postanalytical variables (SD: 20%); 52% of preanalytical variables (SD: 11%); and 43% of the analytical variables studied (SD: 18%). Finally, half the CPGs included a laboratory professional among its authors.

Conclusions

CPGs frequently failed to provide relevant laboratory-related information. Laboratory professionals were co-authors in only half the CPGs. There is scope for improvement, and laboratory professionals should be included in multidisciplinary teams involved in the development of CPGs.

Total Clinical Chemistry Laboratory Errors and Evaluation of the Analytical Quality Control Using Sigma Metric for Routine Clinical Chemistry Tests

BACKGROUND

Currently, the use of clinical laboratory tests is growing at a promising rate and about 80% of the clinical decisions made are based on the laboratory test results. Therefore, it is a major task to achieve quality service. This study was conducted to assess the magnitude of errors in the total testing process of Clinical Chemistry Laboratory and to evaluate analytical quality control using sigma metrics.

METHODS

A cross-sectional study was conducted at Dessie Comprehensive Specialized Hospital Clinical Chemistry Laboratory, Northeast Ethiopia, from 10 February 2020 to 10 June 2020. All Clinical Chemistry Laboratory test requests with their respective samples, external quality control and all daily internal quality control data during the study period were included in the study. Data were collected using a prepared checklist and analyzed using SPSS version 21.

RESULTS

A total of 4719 blood samples with their test requests were included in the study. Out of 145,383 quality indicators, an error rate of 22,301 (15.3%) was identified in the total testing process. Of the total errors, 76.3% were pre-analytical, 2.1% were analytical and 21.6% were post-analytical errors (p<0.0001). Of the total 14 analytes in the sigma metric evaluation, except ALP, all routine clinical chemistry tests were below the standard (<3). In multivariate logistic regression, the location of patients in the inpatient department was significantly associated with the specimen rejection ((AOR=1.837, 95% CI (1.288-2.618), p=0.001).

CONCLUSION

The study found a higher frequency of errors in the total testing process in the Clinical Chemistry Laboratory and almost all test parameters had an unsatisfactory sigma metric value.

Questionnaire-based Study to Assess Knowledge of Preanalytical Phase of Laboratory Testing Among Trainee Doctors in a Tertiary Care Hospital Medical College

Objective  To determine the knowledge base of common laboratory practices related to preanalytical phase of laboratory testing among medical interns and first-year postgraduate residents in a tertiary care hospital medical college.

Materials and methods  Questionnaire-based survey on preanalytical phase of laboratory testing was conducted among 208 participants, who volunteered and were MBBS interns and first-year postgraduate residents in a medical college, over the period from June 2018 to December 2019. A total of 15-item, multiple-choice questions (MCQs) were included, of which four were opinion-based and not considered for analysis. Responses were further categorized based on percentages with correct response, so we could identify specific knowledge points which need training.

Statistical analysis  Results were analyzed using Microsoft Excel functions and a simple calculator.

Results  A total of 208 participants were included in the study, which consisted of an equal number of interns (104) and first-year postgraduate residents (104). The term “preanalytical error” was known to 62.5% of participants. Only 9.62% participants took formal training in phlebotomy. Topics related to questions like coagulation testing, ideal fasting duration, mixing of blood, and order of draw received less than 40% correct response which meant that it requires more training.

Conclusions  In this era of evidence-based medicine, central laboratory plays a pivotal role in patient management, and quality of laboratory results are of paramount importance. Over a period of time, automation technology has reduced analytical phase errors to the minimum. Most errors reported are part of the preanalytical phase, and it has been found that a majority of them are committed due to a lack of knowledge and skills. In order to improve the preanalytical phase and make it as error-free as possible, the staff (technicians, nurses, and trainee doctors) should be constantly motivated and trained.

Current and emerging concepts in biological and analytical variation applied in clinical practice

A single laboratory result actually represents a range of possible values, and a given laboratory result is impacted not just by the presence or absence of disease, but also by biological variation of the measurand in question and analytical variation of the equipment used to make the measurement. Biological variation refers to variability in measurand concentration or activity around a homeostatic set point. Knowledge of biological and analytical variation can be used to facilitate interpretation of patient clinicopathologic data and is particularly useful for interpreting serial patient data and data at or near reference limits or clinical decision thresholds. Understanding how biological and analytical variation impact laboratory results is of increasing importance, because veterinarians evaluate serial data from individual patients, interpret data from multiple testing sites, and use expert consensus guidelines that include decision thresholds for clinicopathologic data interpretation. The purpose of our report is to review current and emerging concepts in biological and analytical variation and discuss how biological and analytical variation data can be used to facilitate clinicopathologic data interpretation. Inclusion of veterinary clinical pathologists having expertise in laboratory quality management and biological variation on research teams and veterinary practice guideline development teams is recommended, to ensure that various considerations for clinicopathologic data interpretation are addressed.

Prostate cancer screening: guidelines review and laboratory issues

Background Prostate-specific antigen (PSA) remains as the most used biomarker in the detection of early prostate cancer (PCa). Clinical practice guidelines (CPGs) are produced to facilitate incorporation of evidence into clinical practice. This is particularly useful when PCa screening remains controversial and guidelines diverge among different medical institutions, although opportunistic screening is not recommended. Methods We performed a systematic review of guidelines about PCa screening using PSA. Guidelines published since 2008 were included in this study. The most updated version of these CPGs was used for the evaluation. Results Twenty-two guidelines were selected for review. In 59% of these guidelines, recommendations were graded according to level of evidence (n = 13), but only 18% of the guidelines provided clear algorithms (n = 4). Each CPG was assessed using a checklist of laboratory issues, including pre-analytical, analytical, and post-analytical factors. We found that laboratory medicine specialists participate in 9% of the guidelines reviewed (n = 2) and laboratory issues were frequently omitted. We remarked that information concerning the consequences of World Health Organization (WHO) standard in PSA testing was considered by only two of 22 CPGs evaluated in this study. Conclusions We concluded that the quality of PCa early detection guidelines could be improved properly considering the laboratory issues in their development.

Prevalence and types of preanalytical error in hematology laboratory of a tertiary care hospital in South India

BACKGROUND

An important component of laboratory medicine is preanalytical phase. Since laboratory report plays a major role in patient management, more importance should be given to the quality of laboratory tests.

AIM

The present study was undertaken to find the prevalence and types of preanalytical errors at a tertiary care hospital in South India.

MATERIALS AND METHODS

In this cross-sectional study, a total of 118,732 samples ([62,474 outpatient department [OPD] and 56,258 inpatient department [IPD]) were received in hematology laboratory. These samples were analyzed for preanalytical errors such as misidentification, incorrect vials, inadequate samples, clotted samples, diluted samples, and hemolyzed samples.

RESULTS

The overall prevalence of preanalytical errors found was 513 samples, which is 0.43% of the total number of samples received. The most common preanalytical error observed was inadequate samples followed by clotted samples. Overall frequencies (both OPD and IPD) of preanalytical errors such as misidentification, incorrect vials, inadequate samples, clotted samples, diluted samples, and hemolyzed samples were 0.02%, 0.05%, 0.2%, 0.12%, 0.02%, and 0.03%, respectively.

CONCLUSION

The present study concluded that incorrect phlebotomy techniques due to lack of awareness is the main reason for preanalytical errors. This can be avoided by proper communication and coordination between laboratory and wards, proper training and continuing medical education programs for laboratory and paramedical staffs, and knowledge of the intervening factors that can influence laboratory results.

Determining qualitative effect size ratings using a likelihood ratio scatter matrix in diagnostic test accuracy systematic reviews

Background Diagnostic test accuracy (DTA) systematic reviews (SRs) characterize a test's potential for diagnostic quality and safety. However, interpreting DTA measures in the context of SRs is challenging. Further, some evidence grading methods (e.g. Centers for Disease Control and Prevention, Division of Laboratory Systems Laboratory Medicine Best Practices method) require determination of qualitative effect size ratings as a contributor to practice recommendations. This paper describes a recently developed effect size rating approach for assessing a DTA evidence base. Methods A likelihood ratio scatter matrix will plot positive and negative likelihood ratio pairings for DTA studies. Pairings are graphed as single point estimates with confidence intervals, positioned in one of four quadrants derived from established thresholds for test clinical validity. These quadrants support defensible judgments on "substantial", "moderate", or "minimal" effect size ratings for each plotted study. The approach is flexible in relation to a priori determinations of the relative clinical importance of false positive and false negative test results. Results and conclusions This qualitative effect size rating approach was operationalized in a recent SR that assessed effectiveness of test practices for the diagnosis of Clostridium difficile. Relevance of this approach to other methods of grading evidence, and efforts to measure diagnostic quality and safety are described. Limitations of the approach arise from understanding that a diagnostic test is not an isolated element in the diagnostic process, but provides information in clinical context towards diagnostic quality and safety.

Quality assurance of genetic laboratories and the EBTNA practice certification, a simple standardization assurance system for a laboratory network

Analytical laboratory results greatly influence medical diagnosis, about 70% of medical decisions are based on laboratory results. Quality assurance and quality control are designed to detect and correct errors in a laboratory’s analytical process to ensure both the reliability and accuracy of test results. Unreliable performance can result in misdiagnosis and delayed treatment. Furthermore, improved quality guarantees increased productivity at a lower cost. Quality assurance programmes include internal quality control, external quality assessment, proficiency surveillance and standardization. It is necessary to try to ensure compliance with the requirements of the standards at all levels of the process. The sources of these standards are the International Standards Organization (ISO), national standards bodies, guidelines from professional organisations, accreditation bodies and governmental regulations. Laboratory networks increase the performance of laboratories in support of diagnostic screening programme. It is essential that genetic laboratories of a network have procedures underpinned by a robust quality assurance system to minimize errors and to reassure the clinicians and the patients that international standards are being met. This article provides an overview of the bases of quality assurance and its importance in genetic tests and it reports the EBTNA quality assurance system which is a clear and simple system available for access to adequate standardization of a genetic laboratory’s network.

An overview of EFLM harmonization activities in Europe

The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has initiated many harmonization activities in all phases of the examination process. The EFLM is dealing with both the scientific and the educational aspects of harmonization, with the intention of disseminating best practice in laboratory medicine throughout Europe. Priorities have been given (1) to establish a standard for conducting and assessing biological variation studies and to construct an evidence based EFLM webpage on biological variation data, (2) to harmonize preanalytical procedures by producing European guidelines, (3) to improve test ordering and interpretation, (4) to produce other common European guidelines for laboratory medicine and play an active part in development of clinical guidelines, (5) to establish a common basis for communicating laboratory results to patients, (6) to harmonize units of measurement throughout Europe, (7) to harmonize preanalytical procedures in molecular diagnostics and (8) to harmonize and optimize test evaluation procedures. The EFLM is also now launching the 5th version of the European Syllabus to help the education of European Specialists in Laboratory Medicine (EuSpLM), which is being supported by the development of e-learning courses. A register of EuSpLM is already established for members of National Societies in EU countries, and a similar register will be established for specialists in non-EU countries.

Quantitative assessment of prevalence of pre-analytical variables and their effect on coagulation assay. Can intervention improve patient safety?

BACKGROUND

Very few Indian studies exist on evaluation of pre-analytical variables affecting "Prothrombin Time" the commonest coagulation assay performed. The study was performed in an Indian tertiary care setting with an aim to assess quantitatively the prevalence of pre-analytical variables and their effects on the results (patient safety), for Prothrombin time test. The study also evaluated their effects on the result and whether intervention, did correct the results.

METHODS

The firstly evaluated the prevalence for various pre-analytical variables detected in samples sent for Prothrombin Time testing. These samples with the detected variables wherever possible were tested and result noted. The samples from the same patients were repeated and retested ensuring that no pre-analytical variable is present. The results were again noted to check for difference the intervention produced.

RESULTS

The study evaluated 9989 samples received for PT/INR over a period of 18 months. The prevalence of different pre-analytical variables was found to be 862 (8.63%). The proportion of various pre-analytical variables detected were haemolysed samples 515 (5.16%), over filled vacutainers 62 (0.62%), under filled vacutainers 39 (0.39%), low values 205 (2.05%), clotted samples 11 (0.11%), wrong labeling 4 (0.04%), wrong vacutainer use 2 (0.02%), chylous samples 7 (0.07%) and samples with more than one variable 17 (0.17%). The comparison of percentage of samples showing errors were noted for the first variables since they could be tested with and without the variable in place. The reduction in error percentage was 91.5%, 69.2%, 81.5% and 95.4% post intervention for haemolysed, overfilled, under filled and samples collected with excess pressure at phlebotomy respectively.

CONCLUSION

Correcting the variables did reduce the error percentage to a great extent in these four variables and hence the variables are found to affect "Prothrombin Time" testing and can hamper patient safety.

Could accreditation bodies facilitate the implementation of medical guidelines in laboratories?

Several studies have shown that recommendations related to how laboratory testing should be performed and results interpreted are limited in medical guidelines and that the uptake and implementation of the recommendations that are available need improvement. The EFLM/UEMS Working Group on Guidelines conducted a survey amongst the national societies for clinical chemistry in Europe regarding development of laboratory-related guidelines. The results showed that most countries have guidelines that are specifically related to laboratory testing; however, not all countries have a formal procedure for accepting such guidelines and few countries have guideline committees. Based on this, the EFLM/UEMS Working Group on Guidelines conclude that there is still room for improvement regarding these processes in Europe and raise the question if the accreditation bodies could be a facilitator for an improvement.

The role of laboratory in ensuring appropriate test requests

This review highlights the role of laboratory professionals and the strategies to be promoted in strict cooperation with clinicians for auditing, monitoring and improving the appropriateness of test request. The introduction of local pathways and care maps in agreement with international and national guidelines as well as the implementation of reflex testing and algorithms have a central role in guiding test request and in correcting the overuse/misuse of tests. Furthermore, removing obsolete tests from laboratory menu and vetting of restricted tests is recommended to increase cost-effectiveness. This saves costs and permits to introduce new biomarkers with increased diagnostic accuracy with a better impact on patient outcome. An additional issue is concerning the periodicity of (re)testing, accounting that only a minority of tests may be ordered as often as necessary. In the majority of cases, a minimum retesting interval should be introduced. The availability of effective computerised order entry systems is relevant in ensuring appropriate test requests and in providing an aid by automated rules that may stop inappropriate requests before they reach the laboratory.

Why are clinical practice guidelines not followed?

Clinical practice guidelines (CPG) are written with the aim of collating the most up to date information into a single document that will aid clinicians in providing the best practice for their patients. There is evidence to suggest that those clinicians who adhere to CPG deliver better outcomes for their patients. Why, therefore, are clinicians so poor at adhering to CPG? The main barriers include awareness, familiarity and agreement with the contents. Secondly, clinicians must feel that they have the skills and are therefore able to deliver on the CPG. Clinicians also need to be able to overcome the inertia of "normal practice" and understand the need for change. Thirdly, the goals of clinicians and patients are not always the same as each other (or the guidelines). Finally, there are a multitude of external barriers including equipment, space, educational materials, time, staff, and financial resource. In view of the considerable energy that has been placed on guidelines, there has been extensive research into their uptake. Laboratory medicine specialists are not immune from these barriers. Most CPG that include laboratory tests do not have sufficient detail for laboratories to provide any added value. However, where appropriate recommendations are made, then it appears that laboratory specialist express the same difficulties in compliance as front-line clinicians.

Bias in clinical chemistry

Clinical chemistry uses automated measurement techniques and medical knowledge in the interest of patients and healthy subjects. Automation has reduced repeatability and day-to-day variation considerably. Bias has been reduced to a lesser extent by reference measurement systems. It is vital to minimize clinically important bias, in particular bias within conglomerates of laboratories that measure samples from the same patients. Small and variable bias components will over time show random error properties and conventional random-error based methods for calculating measurement uncertainty can then be applied. The present overview of bias presents the general principles of error and uncertainty concepts, terminology and analysis, and suggests methods to minimize bias and measurement uncertainty in the interest of healthcare.

Types and Frequency of Errors during Different Phases of Testing At a Clinical Medical Laboratory of a Teaching Hospital in Tehran, Iran

BACKGROUND

According to official data, 60-70% of clinical decisions about hospitalization and discharge are based on laboratory results.

AIMS

The objective of this study is to examine the frequency of errors before, during, and after analysis in a major medical laboratory.

MATERIALS AND METHODS

This descriptive, cross-sectional study was conducted throughout 2012 (January-December 2012). Errors are recorded by the Quality Control Committee in a specially designed record.

RESULTS

A total of 303,866 samples, 2,430,928 tests were received for analysis. The total number of errors was 153,148 (6.3%) (116,392 for inpatients and 36,756 for outpatients). Analysis of the results revealed that about 65.09% of the errors occur across preanalytical phase, whereas 23.2% and 11.68% are related to analytical and postanalytical phase, respectively.

CONCLUSION

More than half of the laboratory errors are related to preanalytical phase; therefore, proper training and knowledge of intervening factors are essential for reducing errors and optimizing the quality.