493.1256 Standard: Control procedures.§ 493.1256 Standard: Control procedures.
(a) For each test system, the laboratory is responsible for having control procedures that monitor the accuracy and precision of the complete analytic process.
(b) The laboratory must establish the number, type, and frequency of testing control materials using, if applicable, the performance specifications verified or established by the laboratory as specified in § 493.1253(b)(3).
(c) The control procedures must -
(1) Detect immediate errors that occur due to test system failure, adverse environmental conditions, and operator performance.
(2) Monitor over time the accuracy and precision of test performance that may be influenced by changes in test system performance and environmental conditions, and variance in operator performance.
(d) Unless CMS approves a procedure, specified in Appendix C of the State Operations Manual (CMS Pub. 7), that provides equivalent quality testing, the laboratory must -
(1) Perform control procedures as defined in this section unless otherwise specified in the additional specialty and subspecialty requirements at §§ 493.1261 through 493.1278.
(2) For each test system, perform control procedures using the number and frequency specified by the manufacturer or established by the laboratory when they meet or exceed the requirements in paragraph (d)(3) of this section.
(3) At least once each day patient specimens are assayed or examined perform the following for -
(i) Each quantitative procedure, include two control materials of different concentrations;
(ii) Each qualitative procedure, include a negative and positive control material;
(iii) Test procedures producing graded or titered results, include a negative control material and a control material with graded or titered reactivity, respectively;
(iv) Each test system that has an extraction phase, include two control materials, including one that is capable of detecting errors in the extraction process; and
(v) Each molecular amplification procedure, include two control materials and, if reaction inhibition is a significant source of false negative results, a control material capable of detecting the inhibition.
(4) For thin layer chromatography -
(i) Spot each plate or card, as applicable, with a calibrator containing all known substances or drug groups, as appropriate, which are identified by thin layer chromatography and reported by the laboratory; and
(ii) Include at least one control material on each plate or card, as applicable, which must be processed through each step of patient testing, including extraction processes.
(5) For each electrophoretic procedure include, concurrent with patient specimens, at least one control material containing the substances being identified or measured.
(6) Perform control material testing as specified in this paragraph before resuming patient testing when a complete change of reagents is introduced; major preventive maintenance is performed; or any critical part that may influence test performance is replaced.
(7) Over time, rotate control material testing among all operators who perform the test.
(8) Test control materials in the same manner as patient specimens.
(9) When using calibration material as a control material, use calibration material from a different lot number than that used to establish a cut-off value or to calibrate the test system.
(10) Establish or verify the criteria for acceptability of all control materials.
(i) When control materials providing quantitative results are used, statistical parameters (for example, mean and standard deviation) for each batch and lot number of control materials must be defined and available.
(ii) The laboratory may use the stated value of a commercially assayed control material provided the stated value is for the methodology and instrumentation employed by the laboratory and is verified by the laboratory.
(iii) Statistical parameters for unassayed control materials must be established over time by the laboratory through concurrent testing of control materials having previously determined statistical parameters.
(e) For reagent, media, and supply checks, the laboratory must do the following:
(1) Check each batch (prepared in-house), lot number (commercially prepared) and shipment of reagents, disks, stains, antisera, (except those specifically referenced in § 493.1261(a)(3)) and identification systems (systems using two or more substrates or two or more reagents, or a combination) when prepared or opened for positive and negative reactivity, as well as graded reactivity, if applicable.
(2) Each day of use (unless otherwise specified in this subpart), test staining materials for intended reactivity to ensure predictable staining characteristics. Control materials for both positive and negative reactivity must be included, as appropriate.
(3) Check fluorescent and immunohistochemical stains for positive and negative reactivity each time of use.
(4) Before, or concurrent with the initial use -
(i) Check each batch of media for sterility if sterility is required for testing;
(ii) Check each batch of media for its ability to support growth and, as appropriate, select or inhibit specific organisms or produce a biochemical response; and
(iii) Document the physical characteristics of the media when compromised and report any deterioration in the media to the manufacturer.
(5) Follow the manufacturer's specifications for using reagents, media, and supplies and be responsible for results.
(f) Results of control materials must meet the laboratory's and, as applicable, the manufacturer's test system criteria for acceptability before reporting patient test results.
(g) The laboratory must document all control procedures performed.
(h) If control materials are not available, the laboratory must have an alternative mechanism to detect immediate errors and monitor test system performance over time. The performance of alternative control procedures must be documented.[68 FR 3703, Jan. 24, 2003; 68 FR 50724, Aug. 22, 2003]