International Council for Standardization in Haematology (ICSH) Guidance on the Validation of Laboratory Developed Tests in Haemostasis

Laboratory developed tests (LDTs) are widely used in clinical hemostasis laboratories. An LDT may be defined as an in vitro diagnostic (IVD) test that is designed, manufactured, and used within a single laboratory. As with all other clinical laboratory tests, LDTs must be validated to ensure fitness for purpose. This may include the assessment of accuracy/comparability, precision, analytical sensitivity, and specificity, reportable range, reference intervals, linearity, and carryover. Not all validation elements will be applicable to all situations, and this will be dictated by the type of assay, the intended use, and the laboratory setting, for example a minor modification of an assay with regulatory approval will require fewer validation procedures than a wholly new test using reagents developed within the laboratory. Many LDTs in the hemostasis laboratory cannot be assessed in the usual fashion, so alternative approaches must be developed.