Waived and Provider Performed Microscopy (PPM) Tests
The Difference Between Waived and PPM Tests
Waived tests are definted to employ methodologies so simple and accurate as to render the likelihood of erroneous results negligible. They pose no reasonable risk of harm to the patient if the test is performed incorrectly, and they are cleared by the Food and Drug Administration for home use.
The original waived test list contained eight groups of tests. The list has been expanded, containing some methods of rapid strep antigen, infectious mono, H. pylori and cholesterol testing.
Less than one percent of all laboratory tests are classified as waived. Laboratories performing only waived tests must follow the manufacturer's instructions (procedures) when performing the tests.
While none of the tests on the original waived list have quality control requirements, it is worth noting that many of the newer waived tests have quality control requirements. Office personnel should very carefully review the manufacturer's instructions. Offices wanting only to perform waived tests must apply for a certificate of waiver (COW). These laboratories are not routinely inspected; however they may be inspected as part of a complaint investigation or on a random basis to determine whether or not only waived tests are being performed.
Waived laboratories are required to pay a $150 biennial certificate fee. Those laboratories with an inspecting agency other than CMS/state agencies should contact their inspecting agencies to inquire about their specific requirements.
Provider Performed Microscopy (PPM)
A subcategory of the moderate complexity level was added after the original CLIA publication. It was first described as physician performed microscopy and is now called provider performed microscopy (PPM). The criteria for classifying these tests include:
- The examination must be performed by a physician or a mid-level practitioner (i.e., nurse practitioners, nurse midwives, and physician assistants) during the patient visit on a specimen obtained from the provider's patient or a patient of the group practice.
- The procedure must be in the moderate complexity category.
- The primary instrument for the test must be a microscope.
- The specimen must be labile or a delay in testing could compromise the accuracy of the test.
- Control materials are not available to monitor the entire testing process.
- Limited specimen handling is required.
The 42 CFR 493- October 2001 indicates that PPM laboratories are subject to Subparts H (Proficiency Testing), J (Patient test Management), K (Quality Control), M (Personnel), and P (Quality Assurance). Because the PPM tests are considered non-regulated, proficiency testing is not specifically required, but a laboratory is responsible for documenting quality assurance. In other words, at a minimum, two split samples for each PPM test should be done yearly. Quality control is required when it is available; control material is available for urine sediments.
Those laboratories with an inspecting agency other than CMS/state agencies should contact their inspecting agencies to inquire about their specific requirements.