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Test Complexities

What is “test complexity”?

Clinical laboratory test systems are assigned a moderate or high complexity category on the basis of seven criteria given in the CLIA regulations. For commercially available FDA-cleared or approved tests, the test complexity is determined by the FDA during the pre-market approval process. For tests developed by the laboratory or that have been modified from the approved manufacturer’s instructions, the complexity category defaults to high complexity per the CLIA regulations. See 42 CFR 493.17.

What is “waived” testing?

As defined by CLIA, waived tests are simple tests with a low risk for an incorrect result. They include certain tests listed in the CLIA regulations, tests cleared by the FDA for home use, and tests approved for waiver by the FDA using the CLIA criteria. Sites performing only waived testing must have a CLIA certificate and follow the manufacturer’s instructions; other CLIA requirements do not apply to these sites.

What is “nonwaived” testing?

Nonwaived testing is the term used to refer collectively to moderate and high complexity testing. Laboratories or sites that perform these tests need to have a CLIA certificate, be inspected, and must meet the CLIA quality standards described in 42 CFR Subparts H, J, K and M.

What are “provider-performed microscopy (PPM)” procedures?

PPM procedures are certain moderate complexity microscopy tests commonly performed by health care providers during patient office visits. The PPM subcategory includes a limited set of microscopic evaluations listed in the CLIA regulations that are performed on samples such as urine, skin scrapings and excretions. CLIA offers a PPM certification option for this limited set of moderate complexity tests to accommodate the unique needs of health care providers in clinical settings. Only certain types of providers qualify as testing personnel for PPM tests under a PPM certificate, including physicians, dentists and midlevel practitioners. See 42 CFR 493.19. Also, CMS’ List of PPMP Tests (including CPT/HCPCS codes).

Do the terms “CLIA exempt,” “FDA cleared,” and “point-of-care testing” mean a test system is CLIA waived?

No. These terms do not relate directly to the test complexity categories, and it cannot be assumed that a test system is waived simply on the basis of being performed at the point of care.
  • “CLIA-exempt” formally refers to a laboratory (not a test system) and means a laboratory that has been licensed or approved by a state where CMS has determined that the state has enacted laws relating to laboratory requirements that are equal to or more stringent than CLIA requirements and the State licensure program has been approved by CMS (42 CFR 493.2).
  • FDA-cleared” means a test system has been reviewed by the FDA and has been determined to be substantially equivalent to a test system already legally marketed for the same use. This could apply to waived, moderate or high complexity test systems.
  • “Point-of-care testing” is a phrase used to describe the location where testing is performed, such as at the bedside or near the site of patient care. While some point-of-care tests are approved for a CLIA waiver, advances in technology that enhance the rapidity of testing are allowing more complex, nonwaived testing to be performed at or near the site of patient care.

Are there situations in which the CLIA regulations are not applicable to testing on human specimens?

Exceptions to the CLIA regulations exist for certain testing, including employment related drug testing by SAMSHA certified laboratories, testing performed for forensic purposes (criminal investigations), and research or surveillance testing performed on human specimens in which patient specific results are not reported (if the results are not used for diagnosis or treatment decisions). For more information, please refer to CLIA at 42 CFR 493.3(b).

How is it determined if a test is moderate or high complexity, or if it is waived?

For moderate and high complexity tests, the FDA evaluates each new commercial test system during the premarket approval process by scoring seven criteria as described in the CLIA regulations. The final score is used to determine whether the test system is classified as moderate or high complexity. See 42 CFR 493.17. For more details, please also see the FDA’s webpage on the CLIA Categorization Criteria and CMS’ webpage on Categorization of Tests.

For waived tests, the FDA may grant a waiver to: 1) any test listed in the regulation, 2) any test system for which the manufacturer or producer applies for waiver if that test meets the statutory criteria and the manufacturer provides scientifically valid data verifying that the waiver criteria have been met, and 3) test systems cleared by the FDA for home use. Please see the FDA’s webpage on CLIA Waivers.

Why is test complexity important?

Clinical laboratories or other testing sites need to know whether a test system is waived, moderate or high complexity for each test on their menu as it determines the applicable CLIA requirements. In general, the more complicated the test, the more stringent the requirements under CLIA. Laboratories or sites that perform only waived tests need only follow the manufacturer’s instructions for those tests to meet CLIA requirements. Nonwaived testing is subject to inspection and must meet the CLIA quality system standards, such as those for proficiency testing, quality control, and personnel requirements. The standards for moderate and high complexity testing differ only in the personnel requirements. The categories of tests a laboratory offers is also a factor in determining the appropriate CLIA certificate for the laboratory. For a general overview of CLIA certificate types, see CMS’ Clinical Laboratory Improvement Amendments (CLIA) Brochure.

How can I check on the test complexity for a specific test system?

The complexity designation may be printed in the manufacturer's package insert or other instructions. In addition, the FDA and CMS websites have several resources: