Minimum Retesting Intervals for Lab Tests

With lab testing representing a high-volume medical activity in Canada, the importance of lab resource stewardship is being addressed by Choosing Wisely Canada through Using Labs Wisely. Using Labs Wisely is a consortium of more than 150 hospitals committed to making a measurable impact on reducing low-value lab testing in Canada.

To support Using Labs Wisely, Canada’s Drug Agency partnered with Choosing Wisely Canada to host a multidisciplinary panel of experts to provide guidance on the minimum retesting intervals of laboratory tests that are commonly repeated in hospitals, health authorities, and community laboratories across the country.  

The Advisory Panel on Minimum Retesting Intervals deliberated on evidence and patient group input to develop recommendations on 5 commonly repeated lab tests in prespecified clinical scenarios:

• antinuclear antibody  
• hemoglobin A1C  
• lipase
• serum protein electrophoresis  
• and thyroid stimulating hormone.  

Minimum retesting intervals are one way to support medical laboratories to identify and manage potentially inappropriate lab test requests. Minimum retesting intervals are not endorsements of repeat testing. They are recommendations that any repeat testing should not be done sooner than the indicated intervals. They are not intended to replace clinical judgment as there may be exceptions in which the recommendations do not apply.

Guidance on Minimum Retesting Intervals  

The Guidance Report presents the advisory panel’s recommendations, how it developed the guidance, and implementation advice for several of the lab tests.  

To support the adoption of the recommendations and provide ease of reference and use, we designed quick guides for each test:  

• antinuclear antibody quick guide  
• hemoglobin A1C quick guide
• lipase quick guide
• serum protein electrophoresis quick guide
• thyroid stimulating hormone quick guide.

The Technology Review includes the evidence gathered for each test that was used by the panel to determine minimum retesting intervals.