Development and use of analytical quality specifications in the in vitro diagnostics medical device industry

Manufacturers of in vitro diagnostic (IVD) medical devices have become integral partners with their customers in determining the quality of laboratory results. Design controls imposed by ISO 9001 quality system standards and various regulations require manufacturers to implement a formal design process, which begins and ends with customer requirements. For IVD systems, this means that manufacturers must establish analytical quality specifications as part of their design input. This provides greater assurance that commercial products will satisfy customer requirements. In the case of quantitative IVD measurement systems, analytical quality specifications include total allowable uncertainty (bias, imprecision, non-specificity). The primary source of customer requirements is the laboratory-customer, who should have established analytical quality specifications based on the needs of its physician-clients. The total allowable uncertainty budget is allocated in the design process to the individual components of the system, such as reagents, instrumentation, calibrators and accessories, and to other factors such as operator, specimen and environmental interactions. Their performance must collectively meet the total allowable uncertainty specification when they are finally integrated into a measurement system. The design control model requires objective evidence that design specifications have been met (verification) and, finally, that the system will satisfy the needs of its intended users (validation). Compliance with the quality system standards is monitored through independent audits, government inspections and post-market surveillance.