Self and proxy rating of quality of life in adults with intellectual disabilities: results from the DISQOL study.
Adults with ID can give reliable quality-of-life data, but proxies usually paint life darker—always gather both and adjust for proxy familiarity.
01Research in Context
What this study did
Schmidt et al. (2010) asked adults with intellectual disability to rate their own quality of life.
They also asked a close proxy—usually a staff member or family member—to rate the same life.
The survey used the short WHOQOL-BREF form and was part of the large DISQOL project.
What they found
Self-ratings and proxy-ratings only matched moderately.
Proxies scored most life areas lower than the adults themselves.
The gap shrank when the proxy knew the adult well and when disability was milder.
How this fits with other research
Spriggs et al. (2015) extended the same sample and showed that unmet needs and heavy medication load drive the gap wider.
Berástegui et al. (2021) repeated the design with younger transition-age youth and found even poorer agreement, hinting that age changes the picture.
Knüppel et al. (2018) ran a near-copy study in autism instead of ID and still saw adults rate life a touch higher than parents, confirming the pattern across diagnoses.
Emerson et al. (2013) warn that both self and proxy data carry validity limits, so treat either source as fallible.
Why it matters
Collect the adult’s own voice first. If you must use proxy scores, note how well the rater knows the client and check for psychiatric meds or unmet needs. Adjust goals and reports so they reflect both views instead of defaulting to the lower proxy mark.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Add a quick question about how long the staff member has known the client before you accept their QoL rating.
02At a glance
03Original abstract
The aim of this study was to analyze the agreement between self and proxy reports of quality of life (QoL) in people with intellectual disabilities and to examine the factors which contribute to these differences. The study was conducted across six international centres in a sample of 614 adults with intellectual disabilities as well as two different samples of proxies (N=874) including both professional carers and relatives. QoL was assessed with the disability version of the WHOQOL-BREF. In both proxy samples results show a significant moderate association between the persons' QoL-assessment and the assessment of their proxies in all of the five QoL domains. There were significant mean differences in most items which varied in their direction. In general, people with disabilities rated their QoL higher than their proxies except for two items from the physical domain. The factors which most significantly contributed to these differences were proxy knowledge of the person as well as the WHODAS-disability score. Cross-cultural differences in the magnitude of concordance were observed. As a conclusion, the study shows a good agreement between the person-proxy QoL-assessments, and that the factors associated with disagreement are limited in this study. Future studies should elaborate the stability of concordance over time.
Research in developmental disabilities, 2010 · doi:10.1016/j.ridd.2010.04.013