Dementia knowledge assessment scale: Development and preliminary psychometric properties

Objectives To develop a reliable and valid dementia knowledge scale to address limitations of existing measures, support knowledge evaluation in diverse populations, and inform educational intervention development. Design A five-stage, systematic scale development process was employed to construct and assess the psychometric properties of the Dementia Knowledge Assessment Scale (DKAS). Setting Data for the study were generated in an online environment and during clinical dementia care placements from Australian (n = 1,321) and international respondents (n = 446). Participants Volunteers from a dementia-related massive open online course (n = 1,651), medical students on clinical placement in a residential aged care facility (n = 40), and members of the Australian health workforce (n = 76). Measurements Psychometric properties of the DKAS were established using a literature review to assess the veracity of scale items, respondent feedback during pilot testing, a Delphi study with dementia experts, construction and review by an expert panel, evaluation of item difficulty, item-total and interitem correlations. Principal components analysis (PCA) was also performed along with measures of test-retest reliability, internal consistency, construct validity, and concurrent validity. Results The pilot DKAS was reduced from 40 to 27 items during analysis. PCA identified four distinct and interpretable factors. The revised DKAS displays high levels of test-retest reliability; internal consistency; and preliminary construct, concurrent, and factorial validity. Conclusion The 27-item DKAS is reliable and shows preliminary validity for the assessment of knowledge deficiencies and change in those who provide care and treatment for people with dementia.