Washington University Clinical Dementia Rating Research Articles

Proxy screening tools improve the recognition of dementia in old-age homes: results of a validation study

Despite the high true prevalence of dementia, demential disorders of residents of old age homes may often be not recognized. There is a need for a standardised tool which includes observations of nursing staff. To describe and validate the Dementia Screening Scale (DSS) for use by nursing staff in old-age homes. All residents of 20 randomly selected old age homes in the city of Mannheim, Germany (n = 1, 922) were rated by nurses using the seven-item proxy dementia rating scale. Based on a subset of residents (n = 598) the DSS was validated against independent diagnostic assessments made by trained psychologists including the Mini-Mental-State-Examination (MMSE), the Dementia Scale of the Brief Assessment Schedule (BAS DEM), and the Washington University Clinical Dementia Rating (CDR). Using the CDR as a gold standard, the DSS correctly classified at a cut-off of 2/3, 85.8% of the mildly, moderately, or severely demented residents. The accuracy of the DSS was only a little worse than that of the MMSE and the BAS DEM. The DSS is well-suited for the recognition of dementia in old age homes. It achieved a better validity than global diagnosis-related staff assessments and compared to performance-based instruments. It is easier to apply, more economic, and associated with a fewer rate of non-response.

The amount of informal and formal care among non‐demented and demented elderly persons—results from a Swedish population‐based study

Developed countries are experiencing a dramatic increase in the proportion of elderly persons, as well as a progressive aging of the elderly population itself. Knowledge regarding the amount of formal and informal care and its interaction at population-based level is limited. To describe the amount of formal and informal care for non-demented and demented persons living at home in a population-based sample. The population consisted of all inhabitants, 75 + years, living in a rural community (n = 740). They were clinically examined by physicians and interviewed by nurses. Dementia severity was measured according to Washington University Clinical Dementia Rating Scale (CDR). Informal and formal care was examined with the RUD (Resource Utilization in Dementia) instrument. The amount of informal care was much greater than formal care and also greater among demented than non-demented. There was a relationship between the severity of the cognitive decline and the amount of informal care while this pattern was weaker regarding formal care. Tobit regression analyses showed a clear association between the number of hours of informal and formal care and cognitive decline although this pattern was much stronger for informal than formal care. Informal care substitutes rather than compliments formal care and highlights the importance of future studies in order to truly estimate the amount of informal and formal care and the interaction between them. This knowledge will be of importance when planning the use of limited resources, and when supporting informal carers in their effort to care for their intimates.

Clinical dementia rating: a reliable and valid diagnostic and staging measure for dementia of the Alzheimer type.

Global staging measures for dementia of the Alzheimer type (DAT) assess the influence of cognitive loss on the ability to conduct everyday activities and represent the "ultimate test" of efficacy for antidementia drug trials. They provide information about clinically meaningful function and behavior and are less affected by the "floor" and "ceiling" effects commonly associated with psychometric tests. The Washington University Clinical Dementia Rating (CDR) is a global scale developed to clinically denote the presence of DAT and stage its severity. The clinical protocol incorporates semistructured interviews with the patient and informant to obtain information necessary to rate the subject's cognitive performance in six domains: memory, orientation, judgment and problem solving, community affairs, home and hobbies, and personal care. The CDR has been standardized for multicenter use, including the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) and the Alzheimer's Disease Cooperative Study, and interrater reliability has been established. Criterion validity for both the global CDR and scores on individual domains has been demonstrated, and the CDR also has been validated neuropathologically, particularly for the presence or absence of dementia. Standardized training protocols are available. Although not well suited as a brief screening tool for population surveys of dementia because the protocol depends on sufficient time to conduct interviews, the CDR has become widely accepted in the clinical setting as a reliable and valid global assessment measure for DAT.

Performance of the Dementia Severity Rating Scale: A Caregiver Questionnaire for Rating Severity in Alzheimer Disease

The Dementia Severity Rating Scale (DSRS) is an informant-based, multiple-choice questionnaire that assesses severity from the mildest to the most severe stages in the major functional and cognitive domains affected in Alzheimer disease (AD). The DSRS has good reliability as measured by making repeated observations over short time periods and by comparing caregiver responses to information collected by a physician or an experienced nonphysician research associate. The measure correlates favorably with the Washington University Clinical Dementia Rating scale and with standard cognitive testing measures. The DSRS provides a simple, valid, and sensitive measure of impairment associated with AD. It is ideally suited for multisite collaborative studies and can be implemented with a minimum of staff time and training.

Application of DSM-III-R criteria for major depressive episode to elderly subjects with and without dementia.

The aim of the present study was to see how DSM-III-R criteria for a major depressive episode functioned in a representative sample of elderly subjects with and without dementia. Data were used from a population-based study of individuals 75 years old or older living in Stockholm. Subjects were screened for dementia by using the Mini-Mental State. Subjects with scores of 23 or lower as well as age- and sex-matched subjects with scores of 24 or higher were given a medical examination. Dementia was diagnosed according to DSM-III-R and staged for severity by using the Washington University Clinical Dementia Rating Scale. The Comprehensive Psychopathological Rating Scale was used to record symptoms of depression, which were then classified according to DSM-III-R criteria for a major depressive episode. Data on depressive symptoms were available for 643 individuals: 213 with and 430 without dementia. A principal component analysis was carried out on the nine symptoms from criterion. A for a major depressive episode. The depressive symptoms clustered into two groups: mood disturbance and motivation disturbance. The mood disturbance symptoms were most frequent in subjects with mild dementia and less frequent in those with more severe dementia; the subjects with the most severe dementia had the highest rates of motivation disturbance symptoms. The different manifestations of depression in elderly patients with and without dementia should be taken into account when making the diagnosis of major depression. Further research is needed on the manifestations of depressive symptoms in the elderly in order to validate the diagnostic criteria.

Interlaboratory Histopathologic Assessment of Alzheimer Neuropathology

Three investigators have applied different histopathologic methods (modified Bielschowsky silver methods, Congo red-gallocyanin) to differentiate Alzheimer's disease (AD) (n = 7 subjects; four with very mild dementia and three with moderate to advanced dementia) neuropathology from brain changes associated with aging in three nondemented individuals who had been evaluated using a validated dementia severity staging instrument [Washington University Clinical Dementia Rating (CDR)] generally within a year of death. The presence of elevated numbers of neocortical (frontal and temporal) diffuse, mature, and total senile plaques (SP) was strongly correlated with the presence of clinical AD but did not equate with CDR dementia severity. Neocortical neurofibrillary tangle (NFT) density as well as hippocampal NFT and SP density in this small series did not differentiate statistically between AD and controls. NFT density appeared to correlate with CDR better than SP density. Quantitative histopathologic assessment of AD markers in only a few brain regions can accurately predict the presence of clinical AD, including the very mild form of the disease. This is especially true for SP in the neocortex.

On the Question of the Mental State of Centenarians

The number of individuals over age 100 years in the United States will increase from 25,000 in 1986 to more than 108,000 by the year 2000. Despite this expected growth there is almost no information about their intellectual function. This is unfortunate since the study of centenarians offers valuable insight into the effects of aging upon the central nervous system. It may also clarify whether Alzheimer''s disease represents premature aging. To better understand their mental state, I evaluated 20 centenarians (17 women and 3 men) with a mean age of 101.75 years. The group completed on average 6.6 years of education and each had 4 illnesses and took 3.5 prescribed drugs. Eighty percent were in nursing homes, mostly due to inadequate social supports. Caregivers had thought that the majority were not demented. During evaluation, 75% had impaired vision while half had disturbed hearing. The speed of thought and body movement were slowed significantly. Centenarians had poor awareness of their environment, in general (p = 0.0019) and had impaired judgement (p = 0.006). Additionally, only 3 individuals had a history and examination to suggest Alzheimer''s disease. Unfortunately, the Folstein Mini-Mental State Exam (MMSE) and the Washington University Clinical Dementia Rating (CDR) were often difficult to score. Mean scores for the MMSE of 7.5 (1 standard deviation, 7.134) and the CDR of 2.08 (1.07) suggested dementia. These observations suggest that impaired intellectual function may be common in this group but there are several limitations on evaluating and interpreting such data.

Impaired eye tracking performance in patients with presenile onset dementia

Smooth pursuit eye movements, saccades and eye blinks were electrooculographically recorded from 26 healthy subjects of different age and 35 patients with presumptive presenile onset dementia (mean age 54), who had to track a light spot which oscillated with different speeds. Older subjects (mean age 51) performed the eye tracking with less accuracy and more saccades than younger ones (mean age 22). 16 patients with stage CDR 1 according to Washington University Clinical Dementia Rating performed smooth pursuit eye movements significantly worse with increased saccade numbers than the Healthy older subjects and lost attention significantly more often which was measured by omitted trackings to presented target oscillations. Their number of eye blinks was partly increased. The test is found suitable for early diagnosis of dementia onset, supporting clinical findings and presumptive diagnosis by objective parameters.

Brief Screening Tests versus Clinical Staging in Senile Dementia of the Alzheimer Type

Several brief screening tests of cognitive function were compared with a reliable and valid global rating of the presence and severity of senile dementia of the Alzheimer type, the Washington University Clinical Dementia Rating (CDR). The six-item Short Blessed Test, the Short Portable Mental Status Questionnaire, the 26-item Blessed Information-Memory-Concentration Test, the Blessed Dementia Scale, and the Blessed Dementia Scale-Cognitive were able to discern both the presence of dementia and its severity. The six-item Short Blessed Test is preferred as a screening test because of its brevity, administration to the subject only, inclusion of a learning task, reliability, and neuropathologic validity. Evidence is presented for the convergent validity of the Initial Subject Protocol, used to derive the Clinical Dementia Rating.

Reliability of the Washington University Clinical Dementia Rating.

There is a growing need for methods for measuring and staging the natural history of dementia of the Alzheimer type. One instrument, designed with that purpose in mind, is the Washington University Clinical Dementia Rating. We tested its reliability using multiple clinicians in a videotape-design study, and it proved reliable under these study conditions.