To determine test need, it is important to establish the value to the Provider. Fundamentally, a test has value if it can do one or more of the following:
- Detect if a patient has a disease
- Confirm a patient's disease or condition
- Classify a patient's disease or condition
- Monitor a patient's disease or condition
A test can do this only if it is efficient, specific, and sensitive. A test is efficient if it can correctly classify a patient as having a specific disease or condition. Sensitivity is the ability to detect a disease and specificity is the ability to positively identify a disease or condition. Most test reagent manufacturers provide the sensitivity and specificity of their test method. If the Providers are mostly interested in screening for a possible disease or condition, they will want a highly sensitive test and will then follow up with a specific (and possibly more expensive) test to confirm that the patient indeed has the disease or condition.
It is the responsibility of the laboratory to make sure the tests added will meet the needs of the Providers.
An example scenario is a Family Practice Clinic that wants to add a COVID SARS 2 test to screen their patients. The vendor indicated that the instrument they had would not be expensive to purchase and provided a waived testing format. Upon reviewing research data provided by the FDA for early approval of the instrument and test, the data showed 80% sensitivity and 100% specificity. Because they wanted a test to rule out COVID SARS 2, this would not be a good solution for their laboratory.
