Validation of the Portuguese version of the Personal Outcomes Scale

Quality of life (QOL) is actually helpful to organizations for guiding personalized support plans and enhance personal outcomes. However, there is a lack of consensus about the QOL construct in the field of intellectual disability (ID). This study aims (a) to analyze the first-order factor structure (i.e., eight domains) of the Portuguese version of the Personal Outcomes Scale (POS), and (b) to compare two alternative models of the higher factor structure of the QOL construct (i.e., Salamanca and Schalock).

Both aims were investigated by examining self-report and report-of-others measures. Data were collected from 1,264 adults with mild or moderate levels of ID and respective proxies.

Results from confirmatory factor analysis (CFA) showed evidence of suitable psychometric properties of the QOL dimensions. Findings also highlighted that the first-order model was more robust than either of the two second-order models. Nevertheless, the Schalock structure was stronger than the Salamanca structure.

Although further research is needed, the results reveal that the Portuguese POS may be a valid and reliable instrument to measure QOL of adults with ID. The implication of these results are discussed highlighting the scale as a useful tool to serve as the basis for planning and evaluating personalized supports.