Attention to the domains of Revised Hasegawa Dementia Scale and Mini-Mental State Examination in patients with Alzheimer's disease dementia

Background: In Japan, Alzheimer's disease dementia (AD) is the most common cognitive disease, and the most widely used dementia screening tests are the Revised Hasegawa Dementia Scale (HDS-R) and Mini-Mental State Examination (MMSE). This study sought to elucidate the relationships of the individual domains of these tests with age and duration of school education in a large group of patients with AD.

Methods: Participants were 505 new outpatients diagnosed with AD who completed the HDS-R and MMSE at the first visit. We investigated the relationships of total and individual domains of these tests with age and duration of school education using the least squares method. Next, we plotted regression lines of the individual domain scores against the total test scores.

Results: Younger age and longer duration of school education were significantly associated with higher total HDS-R and MMSE scores in AD. Domain-specific results indicated that younger age was significantly associated with a higher immediate memory score on both the HDS-R and MMSE and with a higher orientation (time), repetition score on the MMSE. Longer duration of school education was significantly associated with a higher working memory score on the HDS-R and with higher serial 7, repetition and writing scores on the MMSE. In addition, shorter duration of school education was significantly associated with higher naming score on the MMSE. The regression lines of orientation of time, remote memory, visual memory, and verbal frequency hit the bottom on the HDS-R (4/30, 8/30, 4/30, and 6/30, respectively) and of orientation of time, serial 7, remote memory, and writing also hit the bottom on the MMSE (8/30, 9/30, 11/30, and 8/30, respectively).

Conclusions: We should pay attention to age, duration of school education, and the individual domains when using the HDS-R or MMSE to assess patients with AD.