A New Standard in Dementia Knowledge Measurement: Comparative Validation of the Dementia Knowledge Assessment Scale and the Alzheimer's Disease Knowledge Scale.

OBJECTIVES: To compare the psychometric performance of the Dementia Knowledge Assessment Scale (DKAS) and the Alzheimer's Disease Knowledge Scale (ADKS) when administered to a large international cohort before and after online dementia education. DESIGN: Comparative psychometric analysis with pre- and posteducation scale responses. SETTING: The setting for this research encompassed 7,909 individuals from 124 countries who completed the 9-week Understanding Dementia Massive Open Online Course (MOOC). PARTICIPANTS: Volunteer respondents who completed the DKAS and ADKS before (n = 3,649) and after (n = 878) completion of the Understanding Dementia MOOC. MEASUREMENTS: Assessment and comparison of the DKAS and ADKS included evaluation of scale development procedures, interscale correlations, response distribution, internal consistency, and construct validity. RESULTS: The DKAS had superior internal consistency, wider response distribution with less ceiling effect, and better discrimination between pre- and posteducation scores and occupational cohorts than the ADKS. CONCLUSION: The 27-item DKAS is a reliable and preliminarily valid measure of dementia knowledge that is psychometrically and conceptually sound, overcomes limitations of existing instruments, and can be administered to diverse cohorts to measure baseline understanding and knowledge change.

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.