Informed decision making in cancer screening. Why we need a new definition and a new scale to measure it

Informed decision-making (IDM) by individuals, taking into account both potential harms and benefits, is generally considered a necessary quality criterion for population cancer screening programmes. Over the years, the increased attention to potential harms of screening has been reflected in communications to potential participants, indicating a shift from persuasive messaging to communication aimed at IDM. However, to date, there is no agreed-upon definition and no agreed-upon and validated measure of IDM. Definitions are generally based on Rational Choice Theory, although this does not reflect how people make decisions in daily life. Most measures are neither based on solid theory nor validated. This lack of theoretically based and well-validated measures hampers studies assessing IDM as well as the development of interventions to foster IDM. In this paper we review the state-of-the-art of IDM in cancer screening. Additionally, we present an alternative theoretical framework for defining IDM and a new definition of IDM – one that addresses both the decision-making process as well as the conditions necessary for IDM. In addition, we developed and validated a new scale for measuring IDM reported in separate articles. This new scale may be useful for policy and practice in population cancer screening programmes.