Macquarie University
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The implementation of safe and effective high risk result management practices in pathology

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posted on 2022-03-28, 21:35 authored by Craig Anthony Campbell
Numerous national and international patient safety reports have identified failure in the communication of pathology results to the 'clinician responsible for the patient's care' as a significant contributor to unsafe medical care. Although it is standard practice for pathology laboratories to immediately communicate critical results (i.e., results that indicate a high risk of imminent and serious harm to the patient) to the responsible clinician, there is little guidance available to laboratories on how to conduct this task reliably to ensure patient safety. Variations and gaps in critical result management procedures, revealed in international surveys, highlight the importance of and the need for a unified approach. Evidence is also lacking for the thresholds at which pathology results become critical, and due to the differing clinical needs of unique patient populations and settings of care there is no universal consensus on which results should be defined as critical. Some countries have produced "starter" lists of critical result thresholds for laboratories to adapt in collaboration with clinical users to fit their local setting. These starter lists are generally built on expert opinions and state of the art, which make the thresholds difficult to defend when challenged by individual clinicians with contrary views. The aim of this thesis was to establish evidence-based systems for the safe and effective management of critical pathology test results. A narrative review of the current status of international critical result management practices was performed. This review identified the need for a harmonised terminology, highlighted key areas where consistent management practices were necessary and feasible, and offered a conceptual framework and methods for designing evidence-based systems for the timely notification of critical pathology results. A systematic review of critical result thresholds for clinical chemistry, haematology and endocrinology tests was also undertaken to provide an explicit and ranked source of evidence for each of the values. An evidence- and risk-based methodology was developed for the identification and verification of critical result thresholds, which involves reviewing the literature, rating the available evidence, performing a risk analysis (to assess the potential harm associated with use of the proposed threshold), assessing method transferability, considering workload implications and seeking endorsement from stakeholders. A retrospective study across four public hospitals was performed in which critical delta thresholds (for detecting critical change in results) were applied to serum creatinine results in order to identify patients with acute kidney injury (AKI). The value of these critical thresholds was assessed by comparing the incidence of laboratory detected AKI to incidence recorded in the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification diagnosis codes. This thesis has introduced new terminology (alert threshold and alert list) and inspired the creation of other terms (critical risk result, significant risk result, and high risk result) which have been adopted in Australia and the United States to replace the heterogeneous terminology previously in use. The review of critical result management practices informed recently published recommendations by the Royal College of Pathologists of Australasia (RCPA) and the Australasian Association of Clinical Biochemists (AACB), which provide Australasian laboratories and their users with guidance on how to design shared policies and procedures for the management of high risk results. The National Pathology Accreditation Advisory Council (NPAAC) are drawing from these recommendations in their development of a national standard for the communication of high risk pathology results. The systematic review and risk based methodology for determining 'critical result thresholds' (i.e., alert thresholds) have inspired and contributed to an Australian initiative currently underway to produce an evidence-based national harmonised 'critical result threshold list' (i.e., alert list). The retrospective study that identified acute kidney injury using delta alert thresholds showed the value of an AKI alert system in identification of patients that would otherwise be missed and thus go untreated. The study has provided justification for the introduction of AKI alerting at the four hospitals, with a pilot study involving live AKI alerting currently underway.


Table of Contents

Chapter 1: Introduction -- Chapter 2: The current status of international critical result management practices -- Chapter 3: Systematic review of critical result thresholds -- Chapter 4: Evidence- and risk-based methodology for defining alert thresholds -- Chapter 5: Application of high risk delta thresholds to serum creatinine -- Chapter 6: Discussion.


Includes bibliographic references Thesis by publication.

Awarding Institution

Macquarie University

Degree Type

Thesis PhD


PhD, Macquarie University, Faculty of Medicine and Health Sciences, The Australian Institute of Health Innovation

Department, Centre or School

The Australian Institute of Health Innovation

Year of Award


Principal Supervisor

Andrea Horvath

Additional Supervisor 1

Andrew Georgiou


Copyright Craig Anthony Campbell 2020. Copyright disclaimer:




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