The work of Rapley (2003) provides extensive analysis of the Quality of Life (QOL) concept. He firstly
recognizes the complexity of the term and highlights the difficulty of reaching a general consensus on the definition.
QOL is a complex state that can be observed at group, community or individual levels. At an individual level,
Rapley notes that QOL
disease are plentiful, but they are too varied and too specific. As the QOL concept is subjective, certain cultural
components further complicate its definition, since cultural, social and environmental contexts and local values
come into play. Given the difficulties in finding a precise definition, we must start with the most accepted theories,
such as those offered by the WHO (WHOQOL 1997), Cummings (Cummins 1997) and Schalock (2004).