Development and preliminary evaluation of the Decision Support Questionnaire

Professor Jacinta Douglas1, Professor Christine Bigby1

1La Trobe University, Australia

Support for Decision Making enables people with cognitive disabilities to participate in making decisions and exercise control based on their will and preferences. The aim of this study was to develop and complete preliminary psychometric evaluation of the Decision Support Questionnaire (DSQ). The DSQ enables decision supporters of people with either intellectual disabilities or acquired brain injury to identify the strategies they use and the frequency with which they use them.

The DSQ is a 32-item self-report scale. Item-content was derived from systematic literature review and qualitative research evidence from people with intellectual disabilities or acquired brain injury and their supporters. Items use a 4-level Likert response scale: (1) never or rarely; (2) sometimes; (3) often; (4) usually or always. This format allows strategy frequency to be monitored over time and after training. Reliability (Cronbach’s alpha) and validity (sensitivity to change following training) were evaluated. Training consistent with the La Trobe Support for Decision Making Practice Framework was delivered to 23 parents of adults with intellectual disabilities. We hypothesised direction of change for DSQ items and used paired sample t-tests and effect sizes (Cohen’s d) to test the significance and strength of changes.

Content reliability was very good yielding a Cronbach’s alpha of .82. Post-training changes were in the hypothesised direction for 84% of the items and demonstrated significant small-moderate effects (d 0.34-0.46).

The DSQ is the only assessment specifically developed to measure support for decision making strategies used by supporters of people with intellectual disabilities. Our evaluation shows the DSQ is reliable and sensitive change following intervention.


Em. Prof Jacinta Douglas has a long history of research about effective interventions for social inclusion of adults with acquired brain injury and worked closely with the Summer Foundation. She co leads research about supported decision making of people with cognitive disabilities at the LaTrobe Living with Disability Research Centre.