Note: This section will be expanded in the next edition of the tool kit and will provide extensive guidance on test verification and validation procedures
- The terms method validation and method verification are often used interchangeably. Method verification applies to FDA-approved or cleared moderate or high complexity (non-waived) tests: and involves verifying that the manufacturer’s stated performance specifications can be met or exceeded in the end user’s laboratory setting.
- Method validation applies to modified non-waived tests or laboratory-developed tests and involves ESTABLISHING the performance specifications (accuracy, precision, reportable range, reference range, analytical sensitivity, analytical specificity) for a test or method.
- Experiments required to perform method validation are generally more extensive than those to perform method verification.
- Because CAP checklist questions may often apply to either activity, the CAP checklist tends to refer to these activities as method validation.
- Under CLIA88 regulations, waived testing does not require formal method verification or validation other than verifying that the reference range used is appropriate for the population being tested
- Good laboratory practices should involve some degree of verification/validation and some accrediting bodies and jurisdictions impose higher verification standards for waived testing.
- POCT may also frequently be moderately complex, (e.g., blood gas analyses,) so many POCT programs must fully understand and be able to implement formal verification protocols.
- The principles and details of verification or validation protocols should be understood by any Laboratory Director or POCT Coordinator. Overseeing this process is a typical role for a coordinator and technical staff, but a Laboratory Director must approve the process and be involved in setting criteria or expectations for any method’s performance.
- A key point is that the process and performance criteria and expectations must be established BEFORE the validation is begun. These are usually based upon the intended use of the test or device.
- The Laboratory Director should not simply accept the manufacturer’s stated performance specifications (e.g. accuracy, precision) as appropriate for the intended use of the device or test in the institution. He/she must also approve and sign off on any data for method verification or validation before a test can be implemented.
- POCT operators are usually not trained in these processes and have low tolerance for them. That is a strong reason why the Laboratory Director and coordinator are such valuable resources and partners for any POCT program.