Published: 3 Dec 2024

Understanding Your Test Results

Communication with Your Healthcare Provider

While we aim to provide information, we do not intend to replace communication with your healthcare provider. Remember, reference ranges serve as general guidelines for your provider. If you have any questions or concerns about your results, it is essential to consult with your healthcare professional.

Interpretation and Context

Your healthcare provider has a comprehensive understanding of your medical history and current symptoms. They can interpret your test results considering these factors, which is not possible for any website. For a limited number of tests, decision limits (rather than reference ranges) are used to guide clinical decisions based on extensive studies.

Glucose Testing as an Example

For adults undergoing fasting blood glucose testing for type 2 diabetes, a fasting glucose level of 126 mg/dL (7.0 mmol/L) or higher on multiple occasions indicates diabetes. This decision limit is widely used by healthcare providers.

Establishing Reference Ranges

Reference populations are selected based on age, sex, race, health status, or medical history. A statistically significant number of individuals matching this profile undergo testing under controlled conditions.

For many tests, reference ranges represent the middle 95% of values obtained from the reference population. Labs may establish their own ranges, adopt ranges from manufacturers or other labs, or derive ranges from existing patient data.

Defining the reference population is the most crucial step in setting a reference range for any test.