ABSTRACT
It is clear that the field of cancer and health care in general very much need more cost effective ways to obtain new and better data about patient functioning, well-being and other generic health outcomes. The methods must be practical and they must satisfy the most crucial psychometric standards. The trade-off between practical considerations and psychometric standards has led to a rethinking of measurement strategy. An important feature of health is its dimensionality. Health has distinct components, that must be measured and interpreted separately, to fully understand health at a point in time, as well as changes in health over time. Interestingly, almost completely orthogonal to the physical functioning axis is the mental health axis, which includes psychological distress, psychological well-being, and life satisfaction. In most populations individuals at all levels of the physical functioning axis are observed at all levels of the mental health axis.
