Will my results vary from another lab?

The types of tests performed at Everlywell’s clinical laboratories are often the same as those offered at other labs. For example, cholesterol testing is included in Everlywell’s Cholesterol & Lipids Test, but it’s also widely available through hospital laboratories. If you have results from both, what should you expect when comparing them?

In general, results between laboratories using the same test method and sample type will be very similar, though not necessarily identical. This is expected because each lab establishes its own reference ranges—the span of values considered normal or abnormal. The College of American Pathologists (CAP) requires inter-laboratory testing and monitors results to ensure laboratories are operating within an acceptable range.

Sometimes, differences arise because the sample type or testing method is not the same. If either differs from your Everlywell test, you may notice that the numerical values are different.

Everlywell uses minimally invasive methods to collect samples, including:

• Saliva: deposited into a small collection tube
• Dried blood spot: collected by pricking a fingertip with a lancet and applying drops to absorbent paper
• Urine: collected by dipping absorbent paper into the urine stream or into a small container

These sample types are convenient for customers to collect at home, and they remain stable during shipping and storage without affecting test results.

By contrast, many traditional labs rely on venous blood draws, which require a visit to a collection site and trained phlebotomy staff. Venous blood can be separated into whole blood, serum, or plasma. Serum is most commonly used, but it contains proteins that can bind to substances and potentially interfere with measurements. As a result, serum and other sample types may not yield identical values, even on the same test.

An analyte is the substance being measured—for example, cholesterol in a cholesterol test. Cholesterol in serum may be measured by immunoassay or by spectrophotometry. Because these are two different methods, the results may not be directly comparable. However, the reference ranges for each method are designed to produce the same overall interpretation (e.g., normal vs. high risk). Again, CAP ensures that each laboratory test is operating as intended.

If you notice significant differences between your Everlywell results and those from another lab, first confirm whether the sample type and test method were the same. If the overall interpretation (such as normal vs. high risk) is consistent, then the reference ranges are likely different because the test methods are not directly comparable.