Quality of life measurements: a soft outcome--or is it?

In oncology research, quality of life (QOL) has been identified as the second most important outcome, with survival being the most important. The integration of QOL assessments into clinical practice and research presents some unique challenges. QOL outcomes are sometimes perceived to be soft, as opposed to the type of outcomes that provide hard end points or factual data and can be easily defined quantitatively. The softness of QOL outcomes relative to survival and tumor response is cited as a particular barrier to implementation and interpretation of results. This article reviews the importance of QOL to clinical practice, discusses the perceived softness of QOL, and compares the roles of symptoms and QOL scores as they relate to disease progression and tumor response. Providing sound QOL data to healthcare professionals and patients is essential to enable truly informed decision-making.