Spanish-dementia knowledge assessment scale (DKAS-S): psychometric properties and validation

Background Alzheimer's disease (AD) is the most frequent cause of cognitive impairment. Community knowledge of the disease has proven to be a very important aspect of the development of interventions and the evaluation of their effectiveness. However, it is necessary to have standardized and recognized tools in different languages. The aim of the current study was to develop a cross-cultural adaptation of the Spanish Dementia Knowledge Assessment Scale (DKAS-S) and to assess their psychometric properties with cohorts of health students and professional and non-professional caregivers of AD patients from several regions of Spain. Methods We developed and translated the DKAS into Spanish following the forward-back-forward translation procedure. Then, we performed a cross-sectional study to assess the validity, reliability and feasibility of the DKAS-S. We also performed an analysis to obtain test-retest reliability measures. The study was performed in four medical centres across three regions in Spain. From May to September 2019, we administered the scale to students, professional and non-professional caregivers; including a subgroup of non-professional caregivers of patients with early-onset AD (<65years). Results Eight hundred forty-six volunteer participants completed the DKAS-S: 233 students (mean age 26.39.2years), 270 professional caregivers (mean age 42.5 +/- 11.7years) and 343 non-professional caregivers of AD patients. (mean age was 56.4 +/- 13.16). The DKAS-S showed good internal consistency (Cronbach's alpha=0.819) and good test-retest reliability (time 1: 28.1 +/- 8.09 vs time 2: 28.8 +/- 7.96; t=-1.379; p=0.173). Sensitivity to change was also significant in a subgroup of 31 students who received education related to AD and dementias between each administration (time 1: 25.6 +/- 6.03) to (time 2: 32.5 +/- 7.12; t=-5.252, p=0.000). The validity of the construct was verified by confirmatory factor analysis, although there were challenges in the inclusion of some items in the original 4 factors. Conclusions The 25-item DKAS-S showed good psychometric properties for validity and reliability and the factorial analysis when it was administered to a population of students and professional and non-professional caregivers. It was a useful instrument for measuring levels of knowledge about dementia in Spanish population.