Defining patient-reported outcomes.

This paper considers and defines the different types of patient-reported outcomes that can be collected in clinical studies. In particular, it argues that quality of life (QoL) is a distinctly different type of outcome from Health-Related Quality of Life (HRQL). QoL is seen as providing an overall assessment of the effect of both illness and its treatment on the patient. In contrast, HRQL assesses issues that are of clinical or societal importance that may or may not cause concern to the patient. Needs-based QoL is defined and it is argued that this approach (the extent to which an individual is able to meet his or her needs) provides a good working indicator of QoL.