Did you know that something as simple as chewing a piece of gum or drinking a cup of coffee can interfere with certain lab tests?

“Medications, alcohol, nicotine, caffeine, food intake and even exercise can affect the accuracy of laboratory test results. That’s why it is so important to make sure that you understand and follow instructions before you have a lab test,” says Robin Power, a medical laboratory technologist and former president of the Canadian Society for Medical Laboratory Science.

“Up to 85 per cent of decisions about diagnosis and treatment are based on laboratory test results,” says Ms. Power. “A false lab result can have serious consequences. It can delay diagnosis and treatment of a serious health concern or conversely, lead to unnecessary or inappropriate medical treatment.”

CSMLS is urging Canadians to ask for instructions before having a lab test, and to follow those instructions carefully. “If there are specific instructions that you need to follow, a certified medical laboratory professional will be able to explain them to you,” says Ms. Power. She also suggests that people check their laboratory requisition form to ensure that personal information (name, address, etc,...) is recorded accurately.

CSMLS has developed a Lab Test Checklist to help you prepare for your next lab test. Information on laboratory testing is also available on Lab Tests Online.

Lab Test Checklist

Questions for your doctor:

• Why is this test requested?
• What kind of information will the test provide?
• Is this test the only way to find out this information?
• Should I stop taking my medication (prescription, non-prescription, herbal) before the test?

Questions for your medical laboratory professional:

• How is the test done?
• How accurate is the test?
• Will the test be uncomfortable?
• What do I need to do prepare for the test?
• Can I drink before the test? What and how long prior?
• Can I smoke before the test?
• Can I eat before the test?
• Can I exercise before the test?
• Where will the test be done?
• What time is best for collection?
• How long does the test take?
• How will I feel during the test?
• Where do I have to go for the sample collection?
• How long will the collection of the sample take?
• When will the results be sent to my doctor?