Factors Influencing Choice of Laboratory-Developed Tests and US Food and Drug Administration (FDA)-Approved or...

Clinical laboratory tests in the United States have been subject to dichotomous regulatory oversight, encompassing both laboratory-developed tests (LDTs) and US Food and Drug Administration (FDA)-approved or FDA-cleared in vitro diagnostic products (IVDs).

To assess the factors and preferences that are important for the selection of tests by clinical laboratories.

A questionnaire was sent to laboratories participating in College of American Pathologists proficiency testing programs for 5 molecular analytes across molecular oncology, infectious disease, and germline genetics. The questionnaire asked about the factors that influenced the decision to implement an LDT or an FDA IVD.

For all laboratories providing analyte responses, including those using LDTs and FDA IVDs, the factors most rated as very important were assay coverage of specific variants and/or positions of interest (95.1%; 656 of 690) and assay performance (eg, analytical sensitivity and specificity) (92.8%; 666 of 718). Laboratories using LDTs preferentially rated flexibility to modify the assay and already possessing the testing platform/equipment as very important. Laboratories using FDA IVDs preferentially rated the reputation of the assay manufacturer and support and customer service as very important.

This study highlights the primacy of performance for laboratories' selection of assays. The variability of laboratory preferences for LDTs and FDA IVDs illustrates the need for a regulatory approach that minimizes burdens and is flexible so that laboratories can best adapt to their unique clinical environments. These preferences should be considered to reduce impact on laboratories and on patient care as the FDA and other agencies assess regulatory oversight.