A list of primary and secondary testing along with technical protocols and interpretation criteria must be submitted. Primary testing is the test of choice that is the laboratory standard.
Secondary testing is used in conjunction with the primary test for a specific reason.
For example, primary testing would be venous duplex imaging. Photoplethysmography is a secondary testing for venous reflux. An algorithm must be provided for the indications and usage of secondary testing modalities. The protocols should be so explicated that there is no question as to how the exam should be performed. These protocols represent what is routinely performed in your laboratory and must be based on the accepted published standards.