The aim of the study was to apply a method for measuring cognitive functioning in severely demented patients. Reliability and validity of the Hierarchic Dementia Scale (HDS) were tested. Fifty patients with dementia of the Alzheimer's type (DAT), multi-infarct dementia (MID), and dementia of mixed type (MIX) were studied. The interrater reliability was satisfactory as estimated by means of a kappa coefficient. The test retest reliability was rs = .96. The concurrent validity of the HDS, as measured by the correlation between the HDS and the MMSE, was rs = .86, and between the HDS and the CDR was rs = −.71. The results indicate that HDS is a useful and valid instrument for determination of the heterogeneous cognitive deficits in severe dementia.

Recent research on the prevalence of age-associated memory impairment (AAMI) has reflected considerable variability, with estimates ranging from 35% to 98%. This variability is attributed to (a) failure to employ the complete diagnostic criteria for AAMI and (b) failure to consider age as a variable in estimating prevalence. Analysis of published normative data on both standard clinical memory tests and computer-simulated everyday memory tests shows a clear increase in the percentage of persons meeting the AAMI memory performance criterion as a function of age. These data are offered as an upper-bound estimate of the prevalence of AAMI, by age decade.

This study describes how demented immigrants' communicative performance together with caregivers who speak/do not speak these people's native language relates to the demented persons' cognitive, linguistic, and neuropsychological abilities. The study was carried out among demented persons who were born in Finland and had immigrated to Sweden. Their life history, linguistic history and linguistic behavior, and communication in standardized situations were assessed. Neuropsychological and medical examinations were performed for diagnostic reasons. The results show that many of these Finnish immigrants had difficulties communicating with their Swedish-speaking caregivers, while their communication with a Finnish-speaking caregiver was adequate. The frequent misunderstanding of a person's message often leads to a one-way communication, in which the caregiver commands and interrupts the demented person. The demented Finnish immigrants functioned on a level of manifest competence that seemed far below their level of latent competence. It seems reasonable that the presence of Finnish-speaking caregivers is an environmental change that would markedly enhance the demented Finnish immigrants' performance and quality of life and also reduce the costs for their care.