New guidance from an expert panel offers recommendations on minimum retesting intervals for 5 laboratory tests that are commonly repeated in hospitals, health authorities, and community laboratories across the country.

The guidance may help these organizations implement strategies that support the appropriate use of lab tests and address inefficient use of health care resources. The recommendations cover 5 lab tests that are used in prespecified populations or clinical scenarios:

• Antinuclear antibody | Quick Guide
  • People with suspected or confirmed systemic autoimmune disease
• Hemoglobin A1C | Quick Guide
  • People living with diabetes who are on lifestyle modification, glucose-lowering agents, or insulin
• Lipase | Quick Guide
  • People with acute or chronic pancreatitis
• Serum protein electrophoresis | Quick Guide
  • People with confirmed plasma cell dyscrasias
• Thyroid-stimulating hormone | Quick Guide
  • People who are being treated with thyroid replacement therapy for hypothyroidism
  • People who are being treated for hyperthyroidism

To support the adoption of minimum retesting interval recommendations, the panel also developed specific implementation advice for several tests that offer practical advice for labs, including suggested timing for hard stops. In addition, we have created specially designed Quick Guides for each test, which are knowledge translation tools that aim to support labs by providing the key information from the report in 1 to 2 pages.

The minimum retesting interval recommendations are intended to inform decisions about repeat testing. Clinicians should exercise clinical judgment as there may be exceptions and scenarios where the recommendations do not apply. Labs will need to consider their local context and the capabilities of the laboratory information system when implementing minimum retesting intervals. Minimum retesting intervals are not recommendations for repeat testing or the clinical indications in which these tests should be used.

Developing the Guidance

The Advisory Panel on Minimum Retesting Intervals for Lab Tests is an independent, time-limited panel convened by Choosing Wisely Canada and Canada’s Drug Agency. The 7 core panel members bring expertise in laboratory medicine, family practice, and patient lived experience. Additionally, 7 specialist panel members offer clinical experience in a range of disciplines including endocrinology, cardiology, rheumatology, hematology, oncology, and general internal medicine.

When developing guidance, panellists considered evidence from focused literature reviews, input from patient groups, equity considerations, and their own clinical experience. In April 2024, the draft recommendations were publicly posted for feedback to help refine and improve the guidance.

Stewarding Laboratory Resources

Lab tests are a critical component of effective patient care, providing health care providers and patients with important information to make decisions about the diagnosis, treatment, and management of many diseases. It is estimated that provinces and territories spend more than $5 billion annually on this high-volume activity.

Choosing Wisely Canada is addressing the importance of lab resource stewardship through Using Labs Wisely, a consortium of more than 150 hospitals committed to driving the appropriate use of lab testing in Canada. Participating hospitals identified a need for support and guidance on the minimum retesting intervals.

Related Information

• Advisory Panel on Minimum Retesting Intervals for Lab Tests
• Minimum Retesting Intervals for Lab Tests