Levels of Testing Complexity
CLIA categorizes laboratory testing based on its complexity and risk of harm to the patient. The levels of testing complexity are as follows, from least to most complex:
Waived Testing | Urinalysis dipstick |
Moderate Complexity Testing | Complete Blood Count (CBC) |
High Complexity Testing | PCR testing for COVID |
"Complexity" refers to the testing methodologies used and the degree of judgment and interpretation required to perform the test. "Risk of harm to the patient" refers to the risk of patient injury or illness if an error is made and an erroneous result is reported.
The main differences between moderate and high complexity testing are the personnel qualifications and quality control standards; high complexity testing requires more training or testing experience and more frequent quality control runs. Both personnel qualifications and quality control are discussed more in the subsequent pages.
Another category of CLIA laboratory level exists called provider-performed microscopy (PPM). PPMs are a select group of moderately complex microscopy tests commonly performed by health care providers during patient office visits. Tests included in a CLIA Certificate for PPM procedures allow physicians, midlevel practitioners, and dentists to perform certain moderate complexity microscopic examinations in addition to waived testing during a patient’s visit.