According to CMS, "proficiency testing (PT) is the testing of unknown samples sent to a laboratory by an HHS-approved PT program." PT measures the accuracy of the laboratory and its testing equipment, which is important in providing accurate and appropriate patient care.
During this process, proficiency testing organizations send unknown samples to laboratories on a scheduled basis. Laboratory personnel perform tests on those samples and report the results back to the organization. If the test results are within the acceptable limits, then the laboratory has passed the proficiency test and can continue performing diagnostic testing. If the test results are not within the acceptable limits, then various sanctions may apply, such as the loss of ability of performing the test in question. For example, if the test reports a glucose level of 90 mg/dL but the acceptable limits for that sample are 100-110 mg/dL, then sanctions may apply. Potential sanctions may include loss of authorization to perform the test in question for a specified period of time or until appropriate remediation. This is because inaccurate results could lead to inappropriate diagnoses and treatment.
It is important to distinguish competency assessments from proficiency testing. Competency assessments measure the skills of a professional while proficiency testing measures the accuracy of the tests performed by the laboratory.