The Institute of Medicine (2001) in the US defined quality of life it as ‘subjective or objective judgment concerning all aspects of an individual’s existence, including health, economic, political, cultural, environmental, aesthetic, and spiritual aspects’. Narrower definitions have been offered in particular contexts, such as health care. For example, the term health-related quality of life refers to those aspects of quality of life that might be influenced by poor health or by health care. Disease-specific quality-of-life measures have also been suggested, focusing on those aspects of an individual’s life that might be affected by the illness or disease in question. In the dementia area, for example, it is recognised that quality of life extends beyond the cognitive or other symptoms of the condition (Banerjee et al. 2006). However, most generic health-related quality of life measures fail to pick up those aspects of life affected by the condition or its successful treatment, leading to the development of dementia-specific tools (e.g. Smith et al. 2007).

Health-focused measures are generally insufficient in capturing changes in quality of life that result from long-term care. This is because such care is concerned primarily with how an individual functions and their wellbeing, rather than with the biomarkers or symptoms of a disease. There have consequently been a number of suggested ways to conceptualise quality of life that are relevant to the long-term care context. Sloane et al. (2005) and Rodrigues (2017) describe a number of such approaches and discuss some of the most widely used measures. Many of these conceptualisations identify three broad domains as relevant: physical, psychological and also social dimensions. There is also conceptual and operational discussion about who is best placed to judge quality of life along these dimensions. This is given that some people who use long-term care might have cognitive or other difficulties in reporting accurately their state of psychological or other wellbeing. Consequently, Long Term Care (LTC)  quality of life measures might be completed by the individual service users themselves, a family member who knows them well, another unpaid carer, a member of care staff in a residential or other setting, or by third party proxies. Another approach is to use direct behavioural observation.

Quality of life is closed linked to wellbeing or psychological wellbeing. Terminology in the LTC field is rather loose, and these different terms have often been used interchangeably. There are huge swathes of academic theoretical discussion and empirical research dedicated to the conceptualisation, definition, measurement and interpretation of quality of life and wellbeing, and it is not possible even to summarise those debates here. However, it is important to recognise that the consequences of LTC interventions or policies can impact upon both objective and subjective aspects of life. Additionally, that there will usually be a need to distinguish between and ideally measure two different kinds of wellbeing: hedonic and eudaimonic well-being. Hedonic wellbeing is linked to happiness or life satisfaction. Ryan and Deci (2001) describe this kind of wellbeing as ‘pleasure attainment and pain avoidance’. Eudaimonic wellbeing, in the Aristotelian approach, emphasises processes of fulfilment and achievement of potential: it is ‘living well’. Quality of life as operationally defined in many LTC studies comes closer to eudaimonic wellbeing.