The concept of establishing vs verifying analytic claims in method evaluations.

Abstract

The establishment of analytic claims occurs during the method development stage. For commercial methods, the thorough characterization of analytic performance is the responsibility of the manufacturer. The manufacturer establishes performance claims with a high degree of certainty by utilizing statistically sound experimental protocols with sufficient degrees of freedom. The manufacturer should establish performance claims that state the expected performance of the method for the intended spectrum of patients and laboratory environment. The verification of analytic claims occurs by the end-user of the method. The end-user should not have to necessarily repeat the extensive protocol testing of the manufacturer that was used to establish the performance claims. The goals of the method verification study are not to establish analytic performance or to determine if the analytic performance is clinically acceptable, but, simply, to confirm or verify the stated established performance claims of the manufacturer. This implies an abbreviated method evaluation with statistical confirmation that analytic performance is acceptable. Analytic parameters that should be verified are imprecision, inaccuracy (bias), and linearity including analytic sensitivity. Reference ranges should be determined if the patient population is unique, or if the reference range of the analyte is relatively new or unstudied. Principles of method evaluation are discussed.