A new self-rating questionnaire for dementia screening

Abstract

Background The AD8 plays an important role in the early diagnosis of dementia. However, because of cultural and language difference, it is difficult for Chinese subjects to understand and answer questions in AD8. This paper aims to make a new dementia self-rating questionnaire for Chinese people based on the AD8, and to determine its value for dementia screening.  Methods According to early symptoms of dementia and life style of old Chinese people, a dementia self-rating questionnaire was made based on the AD8. The new questionnaire includes 10 questions, and can be finished in 3 min. The reliability and validity was validated by a questionnaire survey in senior citizens older than 50 years in urban Xi'an. All patients were screened by Mini-Mental State Examination (MMSE) and dementia was diagnosed according to Diagnostic and Statistical Manual of Mental Disorders Forth Edition (DSM-Ⅳ) criteria.  Results A total of 620 patients finished the new questionnaire, and among them 17 patients (2.74% ) were diagnosed as dementia. The score of each question in the questionnaire was positively correlated with the total score (r_s = 0.300-0.709; P = 0.000, for all). The Cronbach α was 0.795, indicating that the questionnaire got good internal consistency reliability. Two principal components were extracted, and the cumulative variance contribution ratio was 49.771%. Factor loading of each subitem was > 0.500, indicating a good construct validity. According to receiver operating characteristic (ROC) curve, the critical value was 2, with the sensitivity 94.10% and specificity 82.10%. Youden index was 0.762.  Conclusions The new dementia self-rating questionnaire can detect dementia patients sensitively and correctly, and is very useful for early screening of dementia.

DOI: 10.3969/j.issn.1672-6731.2015.07.009