Time to act mature-Gearing eHealth evaluations towards technology readiness levels.

It is challenging to design a proper eHealth evaluation. In our opinion, the evaluation of eHealth should be a continuous process, wherein increasingly mature versions of the technology are put to the test. In this article, we present a model for continuous eHealth evaluation, geared towards technology maturity. Technology maturity can be determined best via Technology Readiness Levels, of which there are nine, divided into three phases: the research, development, and deployment phases. For each phase, we list and discuss applicable activities and outcomes on the end-user, clinical, and societal front. Instead of focusing on a single perspective, we recommend to blend the end-user, health and societal perspective. With this article we aim to contribute to the methodological debate on how to create the optimal eHealth evaluation design.