Harmonization in laboratory medicine: Blowin' in the wind

The total testing process harmonization: the case study of SARS-CoV-2 serological tests

The total testing process harmonization is central to laboratory medicine, leading to the laboratory test's effectiveness. In this opinion paper the five phases of the TTP are analyzed, describing, and summarizing the critical issues that emerged in each phase of the TTP with the SARS-CoV-2 serological tests that have affected their effectiveness. Testing and screening the population was essential for defining seropositivity and, thus, driving public health policies in the management of the COVID-19 pandemic. However, the many differences in terminology, the unit of measurement, reference ranges and parameters for interpreting results make analytical results difficult to compare, leading to the general confusion that affects or completely precludes the comparability of data. Starting from these considerations related to SARS-CoV-2 serological tests, through interdisciplinary work, the authors have highlighted the most critical points and formulated proposals to make total testing process harmonization effective, positively impacting the diagnostic effectiveness of laboratory tests.

The harmonization issue in laboratory medicine: the commitment of CCLM

The analytical quality of the clinical laboratory results has shown a significant improvement over the past decades, thanks to the joint efforts of different stakeholders, while the comparability among the results produced by different laboratories and methods still presents some critical issues. During these years, Clinical Chemistry and Laboratory Medicine (CCLM) published several papers on the harmonization issue over all steps in the Total Testing Process, training an important number of laboratory professionals in evaluating and monitoring all the criticisms inherent to the pre-analytical, as well as analytical and post analytical phases: from the consensus statement on the most informative testing in emergency setting, to the prevention and detection of hemolysis or to patients identification and tube labeling procedures, as far as to different approaches to harmonize hormones measurements or to describe new reference methods or to harmonize the laboratory report. During these years the commitment of the journal, devoted to the harmonization processes has allowed to improve the awareness on the topic and to provide specific instruments to monitor the rate of errors and to improve patients safety.

Value of biopsy in a cohort of children with high-titer celiac serologies: observation of dynamic policy differences between Europe and North America

Background

Healthcare systems implement change at different rates because of differences in incentives, organizational processes, key influencers, and management styles. A comparable set of forces may play out at the national and international levels as demonstrated in significant differences in the diagnostic management of pediatric Celiac Disease (CD) between European and North American practitioners.

Methods

We use retrospective clinical cohorts of 27,868 serum tissue transglutaminase (tTG) immunoglobulin A levels and 7907 upper gastrointestinal endoscopy pathology reports to create a dataset of 793 pathology reports with matching tTG results between July 1 of 2014 and July 1 of 2018. We use this dataset to characterize histopathological findings in the duodenum, stomach and esophagus of patients as a function of serum tTG levels. In addition, we use the dataset to estimate the local and national cost of endoscopies performed in patients with serum tTG levels greater than 10 times the upper limit of normal.

Results

Using evidence from a US tertiary care center, we show that in the cohort of pediatric patients with high pre-test probability of CD as determined by serum tTG levels, biopsy provides no additional diagnostic value for CD, and that it counter-intuitively introduces diagnostic uncertainty in a number of patients. We estimate that using the European diagnostic algorithms could avoid between 4891 and 7738 pediatric endoscopies per year in the US for evaluation of CD.

Conclusions

This study considers the North American and European management guidelines for the diagnosis of pediatric CD and highlights the slow adoption in North America of evidence-based algorithms developed and applied in Europe for triage of endoscopy and biopsy. We suggest that system dynamics influences that help maintain the status quo in North America include a variety of social and economic factors in addition to medical evidence. This work contributes to the growing body of evidence that the dynamics that largely favor maintaining status quo management policies in a variety of systems extend to clinical medicine and potentially influence clinical decisions at the level of individual patients and the population.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12913-020-05815-0.

Reflex and reflective testing practice in Clinical Biochemistry in the United Kingdom – a national survey

Background/aims

The addition of further tests to patient samples, whether by reflex (automated) methods or reflectively after result review, remains an important function of the diagnostic laboratory. This can assist clinicians with interpretation of results and aid further management. We aimed to investigate how this is performed within Clinical Biochemistry laboratories across the United Kingdom (UK).

Methods

A questionnaire, consisting of 16 clinical scenarios, was circulated to Clinical Biochemistry laboratories across the UK via the Association for Clinical Biochemistry and Laboratory Medicine (ACB) office. The survey sought to examine opinion on what tests are considered reflex and reflective, which staff members are involved in addition of further tests, whether clinicians are contacted and how abnormal results are handled.

Results

Responses were received from 74 laboratories, and data were compiled for each scenario surveyed. The majority of laboratories are adding calcium and magnesium, reflectively, to confirm hyperkalaemia or hypocalcaemia, and a number of additional endocrine tests are also commonly performed in particular scenarios. However, there are variations in what is regarded as reflex and reflective testing, in how this testing is conducted within the laboratory and in the level of communication with the requesting clinician.

Discussion

We present the consensus views of the survey participants for a number of commonly used additional tests within Clinical Biochemistry and a discussion on current reflex and reflective testing practice based on the survey results and evidence, where it exists. There is a need for harmonization and national guidance in this area.

Recommended changes of the current version of the German Rili-BAEK

A number of improvement proposals and corrections of the German Rili-BAEK (Guideline of the German Medical Association on Quality Assurance in Medical Laboratory Examinations) are discussed with special focus on the internal and external quality assurance (IQA/EQA) as well as reference intervals for quantitative results. Particular attention is paid to reconsider the retrospective analysis of control measurements. Such an analysis can be very useful to monitor establishing errors of measurement even before they become critical. The present method “Quadratischer Mittelwert der Messabweichung (QMMA)” has proved to be ineffective. Furthermore, the current idea of a common limit for single control measures and the retrospective statistics must be revised. As a more sophisticated concept, the novel Adaptive Retrospective Monitoring (ARM) has been developed. ARM is recommended as the new minimum requirement for the entire internal quality assurance. Further proposals to enhance clarity are given concerning the release decisions of medical devices and the EQA. Individualized medicine begins with a patient-specific interpretation of analytic results. This requires standardized subgroup-specific reference intervals with smooth age-related adaptations. Only large laboratories are able to ensure the desired specificity and a sufficient statistical significance of self-developed in-laboratory reference intervals. Hence, the need of a central database for harmonized reference intervals is discussed and recommended. Suitable and consistent reference intervals are also an essential prerequisite for unitless laboratory values like the zlog value.

Can citrate plasma be used in exceptional circumstances for some clinical chemistry and immunochemistry tests?

Background

The use of alternative sample matrices may be an advantageous perspective when the laboratory falls short of serum or lithium-heparin plasma for performing clinical chemistry and/or immunochemistry testing. This study was aimed at exploring whether some tests may be performed in citrate plasma as an alternative to lithium-heparin plasma.

Methods

Paired lithium-heparin and citrate plasma samples collected from 55 inpatients were analyzed on Roche Cobas 8000 for 28 different clinical chemistry and immunochemistry parameters. Data obtained in citrate plasma were adjusted for either the dilution factor or using an equation corresponding to the linear regression calculated by comparing unadjusted lithium-heparin and citrate plasma values.

Results

Except for magnesium (+17%) and sodium (+11%), unadjusted values of all remaining analytes were significantly lower in citrate than in lithium-heparin plasma, with bias ranging between −6.4% and −25.9%. The correlation between lithium-heparin and citrate plasma values was generally excellent (i.e. >0.90). The adjustment of citrate plasma values for the dilution factor (i.e. 1.1) was only effective in harmonizing the results of albumin and lipase, whilst the concentration of all other analytes remained significantly different between the two sample matrices. The adjustment of plasma citrate values using corrective formulas was instead effective in harmonizing all parameters, with no results remaining statistically different between the two sample matrices.

Conclusions

Citrate plasma may be used in exceptional circumstances for clinical chemistry and immunochemistry testing as a replacement for lithium-heparin plasma, provided that citrate plasma values are adjusted by using validated corrective equations.