Examining the factor structure and hierarchical nature of the quality of life construct.

The team ran a confirmatory factor analysis on quality-of-life data from 769 adults with mild or moderate intellectual disability. The adults came from 15 different countries. The goal was to see if many small life-domain scores roll up into one big “quality of life” score.

One higher-order factor explained all eight sub-domains. In plain words, a single total score is enough to describe how the adults felt about life. You do not need to report eight separate numbers.

Chiu et al. (2017) later repeated the same math on a Family Quality of Life scale with 400 Taiwanese families. Their results line up: one clean factor works for families too.

Van Gaasbeek et al. (2026) went a step further. They asked what drives life satisfaction for college students with ID. Belonging on campus added extra power after mental-health scores were already counted. This shows the single QoL factor is useful, but you still need to look at social predictors to explain change.

Hermans et al. (2011) reviewed anxiety tools for adults with ID and found most lacked solid proof. Wang et al. (2010) gives those future anxiety researchers a ready-made total-score model to copy.

If you assess QoL for adults with ID, you can now use the total scale score and be confident it means something. No need to juggle eight sub-scores in reports or graphs. When you pick an outcome measure, check if the vendor shows this kind of single-factor proof; if they do not, ask for it.