Relationship between self-report and proxy ratings on assessed personal quality of life-related outcomes

Quality of life scores obtained from self-reports might not be the same as those obtained from a family member or direct support staff. The purpose of the two studies reported in this article was to evaluate further the impact on quality of life scores of self-report vs. proxy ratings. The Personal Outcomes Scale was administered to persons with an intellectual disability. The self-report version, as well as the direct observation version, was administered. In the use of the direct observation form, direct support staff and family members acted as respondents. Study 1, which evaluated the consistency between self-report and direct observation data using support staff as proxy respondents, found significant mean differences between the two respondent groups in three quality of life domains and an acceptable level of internal consistency for both self-report and direct observation strategies. Study 2, which evaluated the difference between self-report (by the client) and proxy ratings (of the same individual) using direct observation interviews with family and support staff as respondents, found some differences between client and staff ratings but no significant differences between client and family ratings. Correlations between respondent group scores fell within the "good category". The authors noted the need for methodological pluralism in quality of life assessment, the importance of self-report by persons with intellectual disability, and the need to develop better and more reliably user-friendly strategies to evaluate quality of life outcomes for those individuals who either do not or cannot respond for themselves