CMS SOM App. C, Tag D5783

(b)(2) Results of control or calibration materials, or both, fail to meet the

laboratory’s established criteria for acceptability. All patient test results obtained

in the unacceptable test run and since the last acceptable test run must be evaluated

to determine if patient test results have been adversely affected. The laboratory

must take the corrective action necessary to ensure the reporting of accurate and

reliable patient test results.

Interpretive Guidelines §493.1282(b)(2)

When an internal control fails to fall within the defined limits of acceptability, the

laboratory must identify the reason for the failure and correct the problem before

resuming testing of patients. The laboratory must evaluate all patient test results since

the last acceptable external control.

Probes §493.1282(b)(2)

When suboptimal staining or improper coverslipping are identified through quality

control procedures, what corrective actions does the laboratory take?

What actions does the laboratory take when controls reflect an unusual trend or are

outside of the acceptable limits and other means of assessing and correcting unacceptable

control values have failed to identify and correct the problem?