The glossary explains some of the words used across this website and covers some key cancer and research terms, which primarily focus on lung cancer.

Quality-adjusted life year (QALY)

A standardised economic measure of an individual’s life expectancy and quality of life.1 One QALY is equal to one year a person lives in perfect health. QALYs are used to evaluate new interventions, such as low-dose computed tomography screening. Decision-makers may compare the net number of QALYs (health benefit) that a screening programme is expected to bring to a population against the projected costs to understand whether it is a cost-effective strategy to implement.2 See also ‘Disability-adjusted life year’ and ‘Cost-effectiveness analysis’

Quality of life

An individual’s perception of their position in life in the context of the culture and value systems in which  they live and in relation to their goals, expectations, standards and concerns.3


  1. National Institute for Health and Care Excellence (NICE). Glossary.  Available from: [Accessed 07/03/22]

  2. National Institute for Health and Care Excellence. 2012. The guidelines manual: Process and methods. London: NICE

  3. Mental Health and Substance Use team. 2012. The World Health Organization Quality of Life (WHOQOL). Geneva, Switzerland: World Health Organization