Evidence-based cellular pathology

Evidence-based pathology: systematic literature reviews as the basis for guidelines and best practices

CONTEXT

Evidence-based medicine has been proposed as a new paradigm for the identification and evaluation of medical information. Best available evidence or data are identified and used as the basis for the diagnosis and treatment of individual patients. Evidence-based pathology has adapted basic evidence-based medicine concepts to the specific needs of pathology and laboratory medicine.

OBJECTIVES

To briefly review the history and basic concepts of evidence-based medicine and evidence-based pathology, describe how to perform and interpret systematic reviews, and discuss how to integrate best evidence into guidelines.

DATA SOURCES

PubMed (National Library of Medicine, Washington, DC) and Web of Science (Thompson Reuters, New York, New York) were used.

CONCLUSIONS

Evidence-based pathology provides methodology to evaluate the quality of information published in pathology journals and apply it to the diagnosis of tissue samples and other tests from individual patients. Information is gathered through the use of systematic reviews, using a method that is less biased and more comprehensive than ad hoc literature searches. Published data are classified into evidence levels to provide readers with a quick impression about the quality and probable clinical validity of available information. Best available evidence is combined with personal experience for the formulation of evidence-based, rather than opinion-based, guidelines that address specific practice needs.

Histopathology and prognosis in human meningiomas

Histopathological grading of human meningiomas is based on criteria adopted by the World Health Organization (WHO). However, interpretation of the defined histopathological criteria is often subjective. The aim of this study was to investigate the clinical and histopathological features in these tumours associated with patient survival. This enables evaluation of current grading guidelines and practice. In this study, 196 primary, intracranial, and consecutively treated patients from one institution were included. All histological sections were reviewed. Survival data were controlled with the Norwegian Cause of Death Registry. Falcine location, sheet-like growth, frequent mitoses, subtotal resection grade, and absence of psammoma bodies were strong prognostic factors. Of these factors, the latter two were statistically significantly associated with decreased time to recurrence in multivariate analyses. The WHO 2000 and 2007 classifications were associated with decreased time to recurrence. However, the grading criteria suggested by Ho et al. (2002) and in this study achieved stronger prognostic values. Easily recognizable histopathological criteria are essential in tumour grading. We suggest that any two of the following three variables can be used to recognize atypical (grade II) meningiomas: absence of psammoma bodies, presence of necrosis, and/or ≥4 mitoses per 10 high power fields.

Evidence-Based Principles in Pathology: Existing Problem Areas and the Development of “Quality” Practice Patterns

Context.—Contrary to the intuitive impressions of many pathologists, several areas exist in laboratory medicine where evidence-based medicine (EBM) principles are not applied. These include aspects of both anatomic and clinical pathology. Some non-EBM practices are perpetuated by clinical “consumers” of laboratory services because of inadequate education, habit, or overreliance on empirical factors. Other faulty procedures are driven by pathologists themselves.

Objectives.—To consider (1) several selected problem areas representing non-EBM practices in laboratory medicine; such examples include ideas and techniques that concern metastatic malignancies, “targeted” oncologic therapy, general laboratory testing and data utilization, evaluation of selected coagulation defects, administration of blood products, and analysis of hepatic iron-overload syndromes; and (2) EBM principles as methods for remediation of deficiencies in hospital pathology, and implements for the construction of “quality” practices in our specialty.

Data Sources.—Current English literature relating to evidence-based principles in pathology and laboratory medicine, as well as the authors' experience.

Conclusions.—Evidence-based medicine holds the promise of optimizing laboratory services to produce “quality” practices in pathology. It will also be a key to restraining the overall cost of health care.

Evidence-based pathology: umbilical cord coiling

The generation of a pathology test result must be based on criteria that are proven to be acceptably reproducible and clinically relevant to be evidence-based. This review de-constructs the umbilical cord coiling index to illustrate how it can stray from being evidence-based. Publications related to umbilical cord coiling were retrieved and analysed with regard to how the umbilical coiling index was calculated, abnormal coiling was defined and reference ranges were constructed. Errors and other influences that can occur with the measurement of the length of the umbilical cord or of the number of coils can compromise the generation of the coiling index. Definitions of abnormal coiling are not consistent in the literature. Reference ranges defining hypocoiling or hypercoiling have not taken those potential errors or the possible effect of gestational age into account. Even the way numerical test results in anatomical pathology are generated, as illustrated by the umbilical coiling index, warrants a critical analysis into its evidence base to ensure that they are reproducible or free from errors.

Standards to support information systems integration in anatomic pathology

CONTEXT

Integrating anatomic pathology information- text and images-into electronic health care records is a key challenge for enhancing clinical information exchange between anatomic pathologists and clinicians. The aim of the Integrating the Healthcare Enterprise (IHE) international initiative is precisely to ensure interoperability of clinical information systems by using existing widespread industry standards such as Digital Imaging and Communication in Medicine (DICOM) and Health Level Seven (HL7).

OBJECTIVE

To define standard-based informatics transactions to integrate anatomic pathology information to the Healthcare Enterprise.

DESIGN

We used the methodology of the IHE initiative. Working groups from IHE, HL7, and DICOM, with special interest in anatomic pathology, defined consensual technical solutions to provide end-users with improved access to consistent information across multiple information systems.

RESULTS

The IHE anatomic pathology technical framework describes a first integration profile, "Anatomic Pathology Workflow," dedicated to the diagnostic process including basic image acquisition and reporting solutions. This integration profile relies on 10 transactions based on HL7 or DICOM standards. A common specimen model was defined to consistently identify and describe specimens in both HL7 and DICOM transactions.

CONCLUSION

The IHE anatomic pathology working group has defined standard-based informatics transactions to support the basic diagnostic workflow in anatomic pathology laboratories. In further stages, the technical framework will be completed to manage whole-slide images and semantically rich structured reports in the diagnostic workflow and to integrate systems used for patient care and those used for research activities (such as tissue bank databases or tissue microarrayers).

Inhibition of classical complement activation attenuates liver ischaemia and reperfusion injury in a rat model

Activation of the complement system contributes to the pathogenesis of ischaemia/reperfusion (I/R) injury. We evaluated inhibition of the classical pathway of complement using C1-inhibitor (C1-inh) in a model of 70% partial liver I/R injury in male Wistar rats (n = 35). C1-inh was administered at 100, 200 or 400 IU/kg bodyweight, 5 min before 60 min ischaemia (pre-I) or 5 min before 24 h reperfusion (end-I). One hundred IU/kg bodyweight significantly reduced the increase of plasma levels of activated C4 as compared to albumin-treated control rats and attenuated the increase of alanine aminotransferase (ALT). These effects were not better with higher doses of C1-inh. Administration of C1-inh pre-I resulted in lower ALT levels and higher bile secretion after 24 h of reperfusion than administration at end-I. Immunohistochemical assessment indicated that activated C3, the membrane attack complex C5b9 and C-reactive protein (CRP) colocalized in hepatocytes within midzonal areas, suggesting CRP is a mediator of I/R-induced, classical complement activation in rats. Pre-ischaemic administration of C1-inh is an effective pharmacological intervention to protect against liver I/R injury.

Computation of semantic similarity within an ontology of breast pathology to assist inter-observer consensus

Computer-assisted consensus in medical imaging involves automatic comparison of morphological abnormalities observed by physicians in images. We built an ontology of morphological abnormalities in breast pathology to assist inter-observer consensus. Concepts of morphological abnormalities extracted from existing terminologies, published grading systems and medical reports were organized in an taxonomic hierarchy and furthermore linked by the relation "is a diagnostic criterion of" according to diagnostic meaning. We implemented position-based, content-based and mixed semantic similarity measures between concepts in this ontology and compared the results with experts' judgment. The position-based similarity measure using both taxonomic and non-taxonomic relations performed as well as the other measures and was used for automatic comparison of morphological abnormalities within the IDEM computer-assisted consensus platform.

Evidence-based medicine in pathology: an introduction

Evidence-based medicine (EBM) is a school of thought that has spread rapidly through medicine in the past 2 decades and is eliciting an increasing interest in Anatomic Pathology and Laboratory Medicine. It has been defined as "the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients." The environmental factors that created a need for EBM and basic concepts of this discipline are reviewed. Methods for the accrual and critical appraisal of the validity of available evidence and its impact, applicability and usefulness in pathology practice are discussed. Basic concepts of bayesian data analysis with an emphasis on concepts such as prior and posterior probability and the use of "holdout" or "test" data are introduced. The future of EBM in pathology is discussed and potential applications of these concepts to pathology practice and research are proposed.