With the extraordinary strain COVID-19 has imposed on laboratory medicine in Canada, a more thoughtful approach to test ordering is especially important. Medical labs are facing critical shortages in blood tubes, devices and lab staffing.

The situation is not unique to Canada. In January, the U.S. Food and Drug Administration (FDA) announced widespread blood tube shortages and urged health care providers to only perform “medically necessary” blood draws. The U.S. has now also limited blood tube exports, which exacerbates the problem for countries that don’t manufacture them, like Canada. Similar shortages have also been reported in the United Kingdom.

To address the need to conserve tubes and critical laboratory resources, the Canadian Society of Clinical Chemists and the Canadian Association of Medical Biochemists assembled two sets of relevant Choosing Wisely Canada recommendations for hospitals and primary care.

Before ordering tests, please consider:

• If and how immediate this test result will change patient management.
• Strategies to minimize collections, e.g., avoid or limit standing orders.
• Avoid duplications, e.g., check previous results.
• Talking to your local lab professionals about how you can help conserve tubes.

Recommendations for Conserving Lab Resources in Primary Care:

1. Don’t do annual screening blood tests unless directly indicated by the risk profile of the patient. | Family Medicine
   DID YOU KNOW 1 in 20 results for healthy individuals fall outside the reference interval? Testing without an indication provides no clinical value, involves numerous blood tubes and unexpected abnormal results can lead to unnecessary follow-up testing.
   
   
2. Don’t support repeat test ordering at a frequency that is not backed by evidence. | Medical Laboratory Science
   DID YOU KNOW up to 20 percent of tests in Canada are repeated too soon after a previous result, and provide little to no change in management or additional clinical information? This significantly affects lab resources and uses precious blood tubes.
   
   
3. Don’t routinely measure vitamin D in low-risk adults. | Family Medicine
   DID YOU KNOW testing in Canada often requires dedicated instruments, tubes and lab staff solely for vitamin D testing? Except in rare circumstances, testing is unnecessary and vitamin D supplements can be used without testing.
   
   
4. Don’t order thyroid function test in asymptomatic patients. | Family Medicine an estimated 25 percent of TSH tests do not conform with ordering guidelines and result in unnecessary blood draws?
   DID YOU KNOW an estimated 25 percent of TSH tests do not conform with ordering guidelines and result in unnecessary blood draws?
   
   
5. Don’t request a serum protein electrophoresis in asymptomatic patients in the absence of otherwise unexplained hypercalcemia, renal insufficiency, anemia or lytic bone lesions.
   | Medical Biochemistry
   DID YOU KNOW serum protein electrophoresis and immunofixation are labour-intensive tests in the lab, and current practice guidelines do not recommend routine screening in the general population?

Recommendations for Conserving Lab Resources in Hospitals:

1. In the inpatient setting, don’t order repeated CBC and chemistry testing in the face of clinical and lab stability. | Internal Medicine
   DID YOU KNOW just one blood draw per day for ‘routine’ daily lab testing can add up to removing the equivalent of ½ a unit of blood per week? The result is 20-30 blood tubes wasted — and iatrogenic anemia has a negative effect on patient outcomes.
   
   
2. Don’t order baseline laboratory studies (complete blood count, coagulation testing or serum biochemistry) for asymptomatic patients undergoing low-risk, non-cardiac surgery. | Anesthesiology
   DID YOU KNOW 1 in 20 results for healthy individuals fall outside the reference interval? Testing without an indication provides no clinical value, involves numerous blood tubes and unexpected abnormal results can unnecessarily delay surgery.
   
   
3. Don’t request a serum protein electrophoresis in asymptomatic patients in the absence of otherwise unexplained hypercalcemia, renal insufficiency, anemia or lytic bone lesions. | Medical Biochemistry
   DID YOU KNOW serum protein electrophoresis and immunofixation are labour-intensive tests in the lab, and the results are affected by acute illness? Often ordering these tests in hospital only leads to repeat testing after the reactive process resolves.
   
   
4. Don’t order ANA as a screening test in patients without specific signs or symptoms of systemic lupus erythematosus or another connective tissue disease. | Rheumatology
   DID YOU KNOW Antinuclear antibodies (ANAs) are measurable in approximately 25 percent of the population and testing in the lab is labour-intensive? Most individuals with a positive ANA do not have an autoimmune disease and are unlikely to develop one.
   
   
5. Don’t order an erythrocyte sedimentation rate (ESR) to screen asymptomatic patients or as a general test to look for inflammation in patients with undiagnosed conditions. | Medical Biochemistry
   DID YOU KNOW ESR is a manual test in many laboratories, often drawn on a blood tube by itself, and takes up to 90 minutes of lab staff time to complete? Currently the special tube for this test is in short supply.