Harmonization of critical values across the GTA hospitals
Critical values aid in the interpretation of patient test results.
Harmonization of critical values used by hospitals and their associated clinical laboratories across the GTA is essential to ensure consistency in the definition and identification of 'critical state' patients.
To assess the feasibility for harmonization of critical values across GTA, we are surveying Laboratory Medicine departments of hospitals in areas of:
- Genetics
- Chemistry
- Hematology
- Pathology
Latest guidelines from the Harmonization of critical values working group
Guidance on Antimicrobial Therapeutic Ranges and Critical Values
Download the full guide as a printable PDF.
This PDF document summarizes our findings for antimicrobial therapeutic ranges and critical values from hospitals within the Greater Toronto Area (GTA), in collaboration with the respective Pharmacy/Infectious Disease departments. The intention of this document is to act as a guide and/or reference for clinical laboratories with respect to reporting levels of antimicrobial drugs that require therapeutic drug monitoring (TDM).
Executive summary
Assays for common antimicrobials requiring TDM are not analytically equivalent and this must be considered when attempting to use harmonized therapeutic ranges and/or critical values.
- Therapeutic ranges used for vancomycin and aminoglycosides are generally similar across institutions, especially for interpretation of trough samples.
- It is still important to consider other factors when interpreting levels in blood such as: severity of infection, dosing strategy, or specific patient population.
- Currently, only two laboratories in the GTA offer voriconazole testing so therapeutic ranges and critical values are all harmonized.
- Consider incorporating quality assurance practices specific to TDM antimicrobial assays to ensure delivery of high-quality service.
See the full PDF guide for details.
Authors / contact
Compiled by the task force on Critical Values
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Defining and reporting on critical values in genetics (update Feb 2023)
Originally published February 8, 2022. Updated and republished February 17, 2023.
Download this guide as a printable PDF.
As part of an initiative to harmonize critical value reporting across genetic laboratories in the Greater Toronto Area (GTA), we sent a survey of 11 questions via email to genetic laboratory directors in Ontario in July 2019 and also September to October 2019 since there was a paucity of data for critical values in genetics.
Based on the data, the Council formulated proposed guidelines that were circulated to individuals from Ontario genetic laboratory centres and respondents of the survey in November 2021, who supplied feedback.
We recommend all genetic laboratories consider implementing these guidelines into their critical value reporting.
Please supply any feedback on the guidelines or their implementation to Dr. Elaine Goh.
Update to guidelines 2023
One year after this guideline was published, we emailed the participating laboratories to gather further feedback.
The Ontario laboratories indicated:
- they were following the guideline
- the guideline allows for standardization of practices across the Ontario genetics laboratories
- slight rewording of the critical results was needed which has been updated below and in the attached PDF download.
Critical patient type
- Prenatal
- Newborn
- Oncology or
- Expedited by the ordering physician
Critical results
- Cytogenetics: Abnormal prenatal aneuploidy, microarray and susceptibility loci
- Molecular: Unexpected results, and pathogenic variants in prenatal setting
Reporting process
- Insufficient or incorrectly labelled samples: Do not limit to reporting via mail
- Critical results: Suggest in addition to routine process to either also call, email and/or fax the ordering provider.
Other resources on this topic
- The report has also been published in the Journal of Applied Laboratory Medicine: Goh ES, Stavropoulos DJ and Adeli K. 2021 Defining and Reporting on Critical Values in Genetics: A Laboratory Survey
- You can read about the project in a news story: Lab tests that impact lives: harmonizing critical values
Authors / contact
Compiled by
Dr. Elaine Goh
Assistant Professor, Department of Laboratory Medicine and Pathobiology, University of Toronto
Division Head of Clinical Genetics, Trillium Health Partners
Contributor
Dr. James Stavropoulos
Assistant Professor, Department of Laboratory Medicine and Pathobiology, University of Toronto and Clinical Lab Director of Genetics at The Hospital for Sick Children
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Biochemistry and Haematology Critical Values Policies Across the GTA
Download this guide as a printable PDF.
This document summarizes our survey findings for policies and thresholds relating to critical values from hospitals within the Greater Toronto Area. This initial assessment into current critical values practices and thresholds will serve as a foundation for consensus recommendations related to critical values for clinical laboratories.
Laboratories Policies Survey: key findings
All surveyed institutions follow a similar framework with regards to critical values policies:
- There is a defined list of tests that warrant having critical value(s) in place in consultation with clinical stakeholders
- Critical results are primarily flagged/identified by the Laboratory Information System (LIS)
- Laboratory staff are primarily responsible for immediate communication of critical values
- The minimum information to be communicated to clinical staff includes test name, test result and patient name, all of which must be read back to laboratory staff
- There is documentation of critical value communication primarily within the LIS
There is opportunity for improvement with respect to auditing and quality management for critical values systems across all institutions
- The frequency and stakeholders involved with periodic audits of critical values is not well-defined across institutions
- Few laboratories monitor quality indicators/measures such as:
- Time elapsed between identification and receipt of critical results
- Critical results flagging rates
Critical Values Survey: key findings
Across 16 participating institutions, we identified a total of 93 tests within Biochemistry and Haematology/Coagulation with critical values - see the downloadable PDF for a full list of tests.
- Download the full Biochemistry and Haematology Critical Values document (PDF)
- Download the summary table (one page) only (PDF)
Of note, there was considerable variability for population-specific critical values across institutions.
- Characteristics used to define a specific population included: sample type, age, inpatient/outpatient status, anticoagulant status
The following tests are likely to be “harmonizable” with respect to critical values within the GTA as they displayed the least variability across institutions:
Low Critical Value
- pCO2
- pO2
- Glucose
- Magnesium
- Osmolality
- Sodium
- Fibrinogen
- Neutrophils
High Critical Value
- pCO2
- Bicarbonate
- Calcium, total
- Calcium, ionized
- Osmolality
- Phosphate
- Hemoglobin
- INR
- Platelets
- Gentamicin, pre-dose
- Phenobarbital
- Theophylline
- Tobramycin, pre-dose
- Vancomycin, pre-dose
Summary and recommendations
This initial assessment into current critical values practices and thresholds has identified commonalities and differences across GTA hospitals. Although it is premature to provide recommendations on the “appropriate” critical values policies, these findings will serve as a foundation for subsequent consensus building with key stakeholders.
The ultimate goal will be to develop and disseminate standardized critical values policies wherever appropriate and possible for the GTA.
Authors / contact
Compiled by
Assistant Professor, Department of Laboratory Medicine & Pathobiology, University of Toronto, Clinical Biochemist, Mount Sinai Hospital
Contributors
Dr. Saranya K. Arnoldo
Assistant Professor, Department of Laboratory Medicine & Pathobiology, University of Toronto
Clinical Biochemist, William Osler Health System
saranya.arnoldo@williamoslerhs.ca
Dr. Daniel R. Beriault
Assistant Professor, Department of Laboratory Medicine & Pathobiology, University of Toronto
Head of Biochemistry, Unity Health Toronto
Daniel.Beriault@unityhealth.to
Dr. Davor Brinc
Assistant Professor, Department of Laboratory Medicine & Pathobiology, University of Toronto
Clinical Chemist, University Health Network
Dr. Paul Yip
Associate Professor, Department of Laboratory Medicine and Pathobiology, Sunnybrook Health Science Centre and University of Toronto
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Defining and Reporting on Critical Values in Genetics: A Laboratory Survey (Paper)
As part of an initiative to harmonize critical value reporting across genetic laboratories in the Greater Toronto Area (GTA), we sent a survey of 11 questions via email to genetic laboratory directors in Ontario in 2019.
The report has been published in the Journal of Applied Laboratory Medicine: Goh ES, Stavropoulos DJ and Adeli K. 2021
Defining and Reporting on Critical Values in Genetics: A Laboratory Survey
Authors / contact
Compiled by
Dr. Elaine Goh
Assistant Professor, Department of LaboratoryMedicine and Pathobiology, University of Toronto
Division Head of Clinical Genetics, Trillium Health Partners
Contributor
Dr. James Stavropoulos
Assistant Professor, Department of Laboratory Medicine and Pathobiology, University of Toronto and Clinical Lab Director of Genetics at The Hospital for Sick Children
Subscribe to the Quality Council mailing list to hear about the latest resources and events
View an update from the project team
Other available guidelines
GP47 Management of Critical- and Significant-Risk Results, 1st Edition
This guideline provides current best practice recommendations for developing and implementing a policy and procedures for the identification, reporting, and management of critical- and significant-risk laboratory results.
It emphasises management responsibilities such as development of the policy, the process, procedures, job descriptions, and monitoring systems that ensure effective reporting and compliance with regulatory requirements.
Relevant publications for further information
Establishing, harmonizing and analyzing critical values in a large academic health center. Hashim IA, et al. Clin Chem Lab Med 2014;52(8):1129-35. doi: 10.1515/cclm-2014-0029. PMID: 24622791.
Critical risk results – an update on international initiatives. Lam Q, et al. eJIFCC. 2016;27(1):66-76. PMID: 27683507.
Laboratory critical values policies and procedures: a College of American Pathologists Q-Probes Study in 623 institutions. Howanitz PJ, et al. Arch Pathol Lab Med. 2002;126(6):663-9. doi: 10.1043/0003-9985(2002)126<0663:LCVPAP>2.0.CO;2. PMID: 12033953.
Harmonization of critical result management in Laboratory Medicine. Campbell CA, et al. Clin Chim Acta. 2014;432:135-47. doi: 10.1016/j.cca.2013.11.004. PMID: 24246790.
