Psychometric Properties and Factor Analysis of the Engagement and Independence in Dementia Questionnaire (EID-Q)

Abstract

Background/Aims: Independence and social engagement are important outcomes for people with dementia. The aim of this study was to conduct an in-depth psychometric assessment of the Engagement and Independence in Dementia Questionnaire (EID-Q), a measure of social independence. Methods: This was an observational study at five NHS sites across England. Participants completed the EID-Q alongside additional measures. Psychometric analysis included internal consistency, test-retest reliability, convergent validity, and factor analyses. Results: A total of 225 people living with dementia completed the study. Internal consistency was excellent (α = 0.921) and the measure remained moderately stable over a 1-week period (ICC = 0.768). Significant correlations were observed between quality of life (r = 0.682) and depression (r = –0.741; both p < 0.001), indicating the importance of these concepts for wellbeing in dementia. Factor analysis indicated the presence of five factors which loaded onto a second order two-factor solution. These latent factors were named “sense of independence” and “social engagement.” Conclusions: The EID-Q demonstrated acceptable psychometric properties and the factor solution had an adequate model fit. The strong correlations suggest that social independence is strongly related to depression and quality of life. Future work will entail an analysis of responsiveness to intervention and further large-scale work.