Validation of the Chinese Version of the Relevant Outcome Scale for Alzheimer's Disease (CROSA)

Objectives:To examine the psychometric properties of the Chinese version of the Relevant Outcome Scale for Alzheimer’s disease (CROSA) among persons with AD (PWAD) and their caregivers in China.Design:A single-arm, open-label, multi-center study.Setting:Two tertiary general hospitals in Shanghai.Participants:A total of 336 PWAD and their family caregivers.Intervention:The PWAD completed a 12-week treatment with memantine after a baseline assessment.Measurements:The CROSA and the Chinese versions of the Mini-Mental State Examination, the Alzheimer’s Disease Assessment Scale-Cognitive Subscale, the Disability Activity of Dementia, the Neuropsychiatric Inventory Questionnaire, the Zarit Caregiver Burden Interview and the Self-Efficacy Questionnaire for Chinese Family Caregivers.Results:The Cronbach’s alpha for the total scale was 0.900, and the intraclass correlation coefficient and Pearson’s correlation coefficient were 0.910 (P < 0.001) and 0.836 (P < 0.001), respectively. Confirmatory factor analysis revealed the two-factor model to be consistent with the original version. For the known-group validity, the total score of the CROSA classified the PWAD into three stages and three MMSE score groups. Moderate to large correlations with the validated scales confirmed the criteria validity of the CROSA, and the convergent validity was confirmed via testing a hypothesized caregiving model; however, only minimal responsiveness was found among the deterioration group after 12 weeks of treatment with memantine.Conclusions:The reliability and validity of the CROSA was good or acceptable for use in daily clinical settings. Further studies are needed to examine the psychometric properties of the scale.