Evaluation and recommendations for adherence marker development by working groups of the workshop

An adherence marker was defined as 'any substance or device that can be used to measure exposure to a prescribed pharmaceutical regimen.' This definition was designed to avoid restrictive terms that might bar interesting options. It was the opinion that coadministration of the marker with the drug under test was neither essential nor necessarily desirable. This article summarizes the deliberations on major issues of adherence marker characteristics and recommendations for marker development prepared by three independent working groups after presentation of the invited papers. The groups were composed of workshop attendees invited for balanced representation of major disciplines and experience. As a basis for their deliberation, all of the workshop initially addressed a panel of specific topics designed to provide a comprehensive assessment of adherence marker technology. Deliberations were summarized by group recorders.