The CERAD neuropsychological assessment battery total score detects and predicts Alzheimer disease dementia with high diagnostic accuracy.

OBJECTIVES: To establish the diagnostic accuracy of the Total Score of the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological assessment battery (CERAD-NP) both for cross-sectional discrimination of Alzheimer disease (AD) dementia and short-term prediction of incident AD dementia. DESIGN: Longitudinal cohort study with two assessments at a 1.5-year interval. SETTING: Primary care sample randomly recruited via medical record registries. PARTICIPANTS: As part of the German Study on Ageing, Cognition, and Dementia (AgeCoDe), a sample of elderly individuals (N = 1,606; mean age: 84 years) was assessed. MEASUREMENTS: Subjects were assessed with the CERAD-NP and followed up for 18 months (97.6% follow-up rate). Logistic regression and receiver-operating-characteristic (ROC) curve analysis were used to compare the diagnostic accuracy of the CERAD-NP Total Score (CTS) with that of single CERAD-NP scores and the Mini-Mental-State-Examination (MMSE) score. RESULTS: ROC curve analysis resulted in excellent (area under the curve [AUC]: 0.97) cross-sectional discrimination between non-AD and AD dementia subjects. Prediction of incident AD dementia with the CTS was also very good (AUC: 0.89), and was significantly better than prediction based on the MMSE. CONCLUSIONS: The cross-sectional results confirm that the CTS is a highly accurate diagnostic tool for detecting AD dementia in elderly primary care patients. In addition, we provide evidence that the CTS is also accurate for the prediction of incident AD dementia. These findings further support the validity of the CTS as an index of overall cognitive functioning for detection and prediction of AD dementia.

The assessment of changes in cognitive functioning: age-, education-, and gender-specific reliable change indices for older adults tested on the CERAD-NP battery: results of the German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe).

OBJECTIVES: The Consortium to Establish a Registry for Alzheimer's Disease-Neuropsychological (CERAD-NP) battery represents a commonly used neuropsychological instrument to measure cognitive functioning in the elderly. This study provides normative data for changes in cognitive function that normally occur in cognitively healthy individuals to interpret changes in CERAD-NP test scores over longer time periods. DESIGN: Longitudinal cohort study with three assessments at 1.5-year intervals over a period of 3 years. SETTING: : Primary care medical record registry sample. PARTICIPANTS: As part of the German Study on Ageing, Cognition, and Dementia in Primary Care Patients, a sample of 1,450 cognitively healthy general practitioner patients, age 75 years and older, was assessed. MEASUREMENTS: Age-, education-, and gender-specific Reliable Change Indices (RCIs) were computed for a 90% confidence interval for selected subtests of the CERAD-NP battery. RESULTS: Across different age, education, and gender subgroups, changes from at least six to nine points in Verbal Fluency, four to eight points in Word List Memory, two to four points in Word List Recall, and one to four points in Word List Recognition indicated significant (i.e. reliable) changes in CERAD-NP test scores at the 90% confidence level. Furthermore, the calculation of RCIs for individual patients is demonstrated. CONCLUSIONS: Smaller changes in CERAD-NP test scores can be interpreted with only high uncertainty because of probable measurement error, practice effects, and normal age-related cognitive decline. This study, for the first time, provides age-, education-, and gender-specific CERAD-NP reference values on the basis of RCI methods for the interpretation of cognitive changes in older-age groups.

Influence of social support on cognitive change and mortality in old age: results from the prospective multicentre cohort study AgeCoDe.

BACKGROUND: Social support has been suggested to positively influence cognition and mortality in old age. However, this suggestion has been questioned due to inconsistent operationalisations of social support among studies and the small number of longitudinal studies available. This study aims to investigate the influence of perceived social support, understood as the emotional component of social support, on cognition and mortality in old age as part of a prospective longitudinal multicentre study in Germany. METHODS: A national subsample of 2,367 primary care patients was assessed twice over an observation period of 18 months regarding the influence of social support on cognitive function and mortality. Perceived social support was assessed using the 14-item version of the FSozU, which is a standardised and validated questionnaire of social support. Cognition was tested by the neuropsychological test battery of the Structured Interview for the Diagnosis of Dementia (SIDAM). The influence of perceived support on cognitive change was analysed by multivariate ANCOVA; mortality was analysed by multivariate logistic and cox regression. RESULTS: Sample cognitive change (N = 1,869): Mean age was 82.4 years (SD 3.3) at the beginning of the observation period, 65.9% were female, mean cognition was 49 (SD 4.4) in the SIDAM. Over the observation period cognitive function declined in 47.2% by a mean of 3.4 points. Sample mortality (N = 2,367): Mean age was 82.5 years (SD 3.4), 65.7% were female and 185 patients died during the observation period. Perceived social support showed no longitudinal association with cognitive change (F = 2.235; p = 0.135) and mortality (p = 0.332; CI 0.829-1.743). CONCLUSIONS: Perceived social support did not influence cognition and mortality over an 18 months observation period. However, previous studies using different operationalisations of social support and longer observation periods indicate that such an influence may exist. This influence is rather small and the result of complex interaction mechanisms between different components of social support; the emotional component seems to have no or only a limited effect. Further research is needed to describe the complex interactions between components of social support. Longer observation periods are necessary and standardised operationalisations of social support should be applied.

The costs of dementia from the societal perspective: is care provided in the community really cheaper than nursing home care?

OBJECTIVE: To compare the costs of care for community-dwelling dementia patients with the costs of care for dementia patients living in nursing homes from the societal perspective. DESIGN: Cross-sectional bottom-up cost of illness study nested within the multicenter German AgeCoDe-cohort. SETTING: Community and nursing homes. PARTICIPANTS: One hundred twenty-eight community-dwelling dementia patients and 48 dementia patients living in nursing homes. INTERVENTION: None. MEASUREMENTS: Utilization and costs of medical care and long term care, including formal and informal social and nursing care based on proxy interviews. Informal care was valued using the replacement cost method. RESULTS: Unadjusted mean annual total costs including informal care were €29,930 ($43,997) for community-dwelling patients and €33,482 ($49,218) for patients living in nursing homes. However, multiple regression analysis controlling for age, sex, deficits in basic and instrumental activities of daily living and comorbidity showed that living in the community significantly increased total costs by €11,344 ($16,676; P < .01) compared with living in a nursing home, mainly due to higher costs of informal care (+€20,585; +$30,260; P < .001). CONCLUSION: From the societal perspective care for dementia patients living in the community tends to cost more than care in nursing homes when functional impairment is controlled for.

Predictors of costs in dementia in a longitudinal perspective.

OBJECTIVE: To analyse predictors of costs in dementia from a societal perspective in a longitudinal setting. METHOD: Healthcare resource use and costs were assessed retrospectively using a questionnaire in four waves at 6-month intervals in a sample of dementia patients (N = 175). Sociodemographic data, dementia severity and comorbidity at baseline, cognitive impairment and impairment in basic and instrumental activities of daily living were also recorded. Linear mixed regression models with random intercepts for individuals were used to analyse predictors of total and sector-specific costs. RESULTS: Impairment in activities of daily living significantly predicted total costs in dementia patients, with associations between basic activities of daily living and formal care costs on the one and instrumental activities of daily living and informal care costs on the other hand. Nursing home residence was associated with lower total costs than residence in the community. There was no effect of cognition on total or sector-specific costs. CONCLUSION: Cognitive deficits in dementia are associated with costs only via their effect on the patients' capacity for activities of daily living. Transition into a nursing home may reduce total costs from a societal perspective, owing to the fact that a high amount of informal care required by severely demented patients prior to transition into a nursing home may cause higher costs than inpatient nursing care.

Depression, non-fatal stroke and all-cause mortality in old age: a prospective cohort study of primary care patients.

BACKGROUND: Depression is a risk factor for stroke and mortality but whether this also holds into old age is uncertain. We therefore studied the association of depression with the risk for non-fatal stroke and all-cause mortality in very old age. METHODS: A representative sample of 3085 primary care patients aged ≥ 75 years were serially assessed during a 6-year follow-up. The relation between depression (Geriatric Depression Scale >6, n=261) and relevant covariates including vascular risk factors and disease, functional and mild cognitive impairment and ApoE genotype on primary care givers information of incident stroke (n=209) and mortality (n=647) were assessed by Cox regression and by competing risk regressions. RESULTS: Depression was not independently associated with incident stroke in fully adjusted models that treated death as the competing event (subdistribution hazard ratio=0.80, 95% confidence interval=0.47 to 1.36). The risk associated with depression was similar for men and women, and for age groups 75-79, 80-84 and ≥ 85 years. In contrast, depression increased all-cause mortality rates, even after adjusting for a range of confounders (hazard ratio=1.31, 95% confidence interval=1.03 to 1.67). LIMITATIONS: We have no information on past depressive episodes and cause of death. CONCLUSIONS: In contrast to reports in younger populations, depression does not appear to increase stroke risk among the old and very old, but continuous to be a risk factor for all-cause mortality.

Effect of cardiovascular and metabolic disease on cognitive test performance and cognitive change in older adults.

OBJECTIVES: To examine the effect of cardiovascular and metabolic diseases on initial cognitive test performance and rate of change in three cognitive measures. DESIGN: Prospective cohort study. SETTING: General practices in six towns throughout Germany. PARTICIPANTS: Three thousand three hundred twenty-seven participants aged 75 and older (average 79.7 ± 3.6). MEASUREMENTS: Data were collected during home visits every 18 months and included sociodemographic variables, depression, disease status, drug intake, and cognition. RESULTS: Although the presence of transient ischemic attack (TIA) or stroke and diabetes mellitus was related to poor initial cognitive test performance, the presence of those and other far-reaching chronic diseases or a higher disease burden were not related to the rate of change in cognition over time. CONCLUSION: Diabetes mellitus, stroke and TIA affect cognitive test performance beyond well-known sociodemographic variables and depressive symptoms, although none of these diseases contributed to cognitive decline over time. In practical terms, prevention and diagnosis of cardiovascular and metabolic diseases may be essential to cognitively healthy aging.

Prediction of dementia in primary care patients.

BACKGROUND: Current approaches for AD prediction are based on biomarkers, which are however of restricted availability in primary care. AD prediction tools for primary care are therefore needed. We present a prediction score based on information that can be obtained in the primary care setting. METHODOLOGY/PRINCIPAL FINDINGS: We performed a longitudinal cohort study in 3.055 non-demented individuals above 75 years recruited via primary care chart registries (Study on Aging, Cognition and Dementia, AgeCoDe). After the baseline investigation we performed three follow-up investigations at 18 months intervals with incident dementia as the primary outcome. The best set of predictors was extracted from the baseline variables in one randomly selected half of the sample. This set included age, subjective memory impairment, performance on delayed verbal recall and verbal fluency, on the Mini-Mental-State-Examination, and on an instrumental activities of daily living scale. These variables were aggregated to a prediction score, which achieved a prediction accuracy of 0.84 for AD. The score was applied to the second half of the sample (test cohort). Here, the prediction accuracy was 0.79. With a cut-off of at least 80% sensitivity in the first cohort, 79.6% sensitivity, 66.4% specificity, 14.7% positive predictive value (PPV) and 97.8% negative predictive value of (NPV) for AD were achieved in the test cohort. At a cut-off for a high risk population (5% of individuals with the highest risk score in the first cohort) the PPV for AD was 39.1% (52% for any dementia) in the test cohort. CONCLUSIONS: The prediction score has useful prediction accuracy. It can define individuals (1) sensitively for low cost-low risk interventions, or (2) more specific and with increased PPV for measures of prevention with greater costs or risks. As it is independent of technical aids, it may be used within large scale prevention programs.