CMS SOM App. C, Tag D2006

(b)The laboratory must examine or test, as applicable, the proficiency testing

samples it receives from the proficiency testing program in the same manner as it

tests patient specimens. This testing must be conducted in conformance with

paragraph (b)(4) of this section. If the laboratory’s patient specimen testing

procedures would normally require reflex, distributive, or confirmatory testing at

another laboratory, the laboratory should test the proficiency testing sample as it

would a patient specimen up until the point it would refer a patient specimen to a

second laboratory for any form of further testing.

Interpretive Guidelines §493.801(b)

Review testing records to determine if special handling was given to PT samples.

Consider the unique requirements of many PT samples when evaluating “same manner”

of testing. The laboratory should document any necessary reconstitution, longer mixing

times, unit conversion of results, etc., as required in §493.801(b)(5).

A laboratory that routinely performs only presumptive testing or screening methods and

refers patient samples to another laboratory for definitive or confirmatory testing or

comparison of test results must not refer PT samples to another laboratory for

confirmatory testing. A laboratory should limit the testing of PT specimens to the

patient testing which is done in-house. With the exception of specimen preparation such

as Immunohistochemistry (IHC) staining, laboratories need to take great care to avoid

sending PT specimens or results to any entity other than their PT provider prior to the PT

testing event cutoff date.

A central laboratory with more than one instrument or methodology for the same test may

alternate methods or instruments from one testing event to the next as long as both are

routinely used to test patient specimens. All samples for one analyte within a shipment

must be tested with the same instrument.

Probes §493.801(b)

• What procedure or test method was used?

• Is this a routine test method used in the laboratory?

• Did routine personnel perform the PT?

• How often were PT samples tested? Does this conform with the laboratory’s

written policies for patient specimens?

• How are deviations from general laboratory practices (if any) justified?

• Do the PT results documented in the laboratory work records (worksheet)

correlate with the results reported to the PT program?

• Do reports submitted to the PT program provider accurately reflect the procedure

(i.e., instrument, method) used in the laboratory?

Check to see if patient samples were reported on the same day that PT samples were

tested. (In a small facility, infrequent testing may necessitate the testing of PT samples

without patient specimens to ensure that the PT test results are returned on time.) Did the

laboratory use the same procedure for both patient specimens and PT samples?