From a concept to a theory: The six eras of quality of life research and application.

Verdugo et al. (2024) traced how quality-of-life ideas grew up.

They split 70 years of work into six clear eras.

The story starts with fuzzy thoughts and ends with a solid theory.

The field moved from "what is QOL?" to "how do we prove it?"

Each era fixed the blind spots of the one before.

Today we have a shared map instead of scattered guesses.

Branford (1997) drew the first six-domain map. Ángel shows that map belongs to Era 2, the "concept" era.

Petry et al. (2007) turned ideas into items using Delphi consensus. Ángel slots that work into Era 3, the "measurement" era.

Adams et al. (2021) gave us six research steps to test the Quality of Life Supports Model. Ángel places those steps in Era 5, the "applied-science" era.

Mercier et al. (2025) looked for pure emotional-well-being tools and found most are just QOL scales in disguise. Their hunt for tighter measures extends Ángel’s story into a seventh chapter.

You no longer have to pick a QOL tool at random.

Use Ángel’s eras like a timeline: choose instruments born in Era 3, pair them with theory from Era 4, and test change with methods from Era 5.

Monday morning, open your client’s file and ask which era their current plan reflects. If it stops at Era 2 "concepts," add a brief standardized scale and move them into Era 3 evidence.