Hi Alice,
For FDA-approved or FDA-cleared assays the instructions for use provided from the manufacturer should not be modified. If the laboratory (and medical director) want to modify a testing procedure, it now becomes a high-complexity test and requires and analytic validation.
The CAP All Common checklist outlines pretty specifically what is required when modifying a test procedure. Just one example of a checklist item is below.
COM.40250: The laboratory follows manufacturer's instructions for all test systems or provides validation records if the test has been modified. NOTE: Following manufacturer's instructions includes performing quality control, calibration,
calibration verification, and related functions as applicable to the scope of testing. Reagents,
fluids, and disposable materials supplied by the laboratory must meet the specifications in the
instructions.
If the laboratory modifies manufacturer's instructions, the test is no longer FDA-cleared/approved,
and the modification(s) must be validated by the laboratory. This requirement also applies to
laboratories not subject to US regulations for tests approved by an internationally recognized
regulatory authority that are modified by the laboratory.
Changes in the specimen type or collection device are examples of common modifications (see
"modification of manufacturer's instructions" in the Definition of Terms). Additional requirements
for validation/verification may be found in the discipline-specific checklists.
For waived and moderately complex tests, if manufacturer instructions are modified,
requirements for high complexity testing apply.
Evidence of Compliance:
✓ Validation records of established performance specifications (accuracy, precision, analytical
sensitivity, analytical specificity, interferences, reference interval(s), and reportable range) of any test that has been modified.
------------------------------
Laura Severs Administrative Laboratory Director
Saint Louis MO
------------------------------