[Assessment of the quality of life]

Assessment of quality of life (qol) is becoming increasingly important, particularly as an outcome variable in assessing the impact of disease, illness and treatment. However, considerable problems exists in formulation, measurement and interpretation of qol. There is as yet no agreed-upon definition of qol nor is there a gold standard measure what complicates the selection of an appropriate assessment scale. The various aspects for the selection of a scale are described.