The current study provided longitudinal robust norms for individuals age 70 years and older for several neuropsychological tests. We compared baseline neuropsychological test performance in three groups free of dementia at baseline: a robust normative sample free of dementia for at least two post-follow-up assessments, an incident dementia sample which developed new onset dementia during the follow-up and a Lost to Follow-up (LTF) sample. ANCOVAs showed that the robust sample performed better on all neuropsychological tests compared to the incident dementia and LTF samples. These findings support the argument that individuals in transition to developing dementia may reduce the mean, increase the variability and therefore underestimate cognitive performance in normal aging. We suggest that longitudinal robust norms may help mitigate the limitations inherent in cross-sectional normative samples.
Aging; Norms; Dementia; Attrition
While gait is widely used to assess health status in older adults, normative data is lacking. Our objective was to develop and compare norms for widely used gait parameters in adults age 70 and older using cross-sectional (conventional) and longitudinal (robust) approaches accounting for important confounders such as disease effects on gait.
Community-dwelling older adults (age>70, N=824) without dementia or disability
Eight quantitative gait parameters measured using an instrumented walkway.
Of the 824 subjects (conventional normal; CN sample), 304 were included in a ‘robust normal’ (RN) sample after excluding those with either prevalent or incident clinical gait abnormalities developing within one year of the baseline assessment to account for disease effects on gait performance. Descriptively, the RN sample showed better performance on all selected gait variables compared to the CN sample. For instance, mean gait velocity (± standard deviation) was 105.9±17.9 cm/sec in the RN sample compared to 93.3±23.2 cm/sec in the overall CN sample. Applying a one standard deviation below the mean (70.1 cm/sec) derived from CN sample to define slow gait, 15.9% (131) in overall cohort were classified as abnormal whereas the RN cut-off (88.0 cm/sec) classified 39.7% (327) in the overall cohort as abnormal.
Our findings suggest that cross-sectional conventional norms may under-estimate gait performance in aging. Longitudinal robust norms provide more accurate estimates of normal gait performance and thus may improve early detection of gait disorders in older adults.
gait; reference values; elderly
The aim of the study was to compare the performance of Robust and Conventional neuropsychological norms in predicting clinical decline among healthy adults and in mild cognitive impairment (MCI). The authors developed Robust baseline cross sectional and longitudinal change norms from 113 healthy participants retaining a normal diagnosis for at least 4 years. Baseline Conventional norms were separately created for 256 similar healthy participants without follow-up. Conventional and Robust norms were tested in an independent cohort of longitudinally studied healthy (n = 223), MCI (n = 136), and Alzheimer’s disease (AD, n = 162) participants; 84 healthy participants declined to MCI or AD (NL→DEC), and 44 MCI declined to AD (MCI→AD). Compared to Conventional norms, baseline Robust norms correctly identified a higher proportion of NL→DEC with impairment in delayed memory and attention-language domains. Both norms predicted decline from MCI→AD. Change norms for delayed memory and attention-language significantly incremented baseline classification accuracies. These findings indicate that Robust norms improve identification of healthy individuals who will decline and may be useful for selecting at-risk participants for research studies and early interventions.
cognition; longitudinal; normative data; decline from normal; mild cognitive impairment
Performance on cognitive tests can be affected by age, education, and also selection bias. We examined the distribution of scores on a several cognitive screening tests by age and educational levels in a population-based cohort.
An age-stratified random sample of individuals aged 65+ years was drawn from the electoral rolls of an urban U.S. community. Those obtaining age and education-corrected scores ≥ 21/30 on the Mini-Mental State Examination were designated as cognitively normal or only mildly impaired, and underwent a full assessment including a battery of neuropsychological tests. Participants were also rated on the Clinical Dementia Rating scale. The distribution of neuropsychological test scores within demographic strata, among those receiving a CDR of 0 (no dementia), are reported here as cognitive test norms. After combining individual test scores into cognitive domain composite scores, multiple linear regression models were used to examine associations of cognitive test performance with age, and education.
In this cognitively normal sample of older adults, younger age and higher education were associated with better performance in all cognitive domains. Age and education together explained 22% of the variation of memory, and less of executive function, language, attention, and visuospatial function.
Older age and lesser education are differentially associated with worse neuropsychological test performance in cognitively normal older adults representative of the community at large. The distribution of scores in these participants can serve as population-based norms for these tests, and be especially useful to clinicians and researchers assessing older adults outside specialty clinic settings.
Neuropsychological tests; epidemiology; normative; community
Neuropsychological tests, including tests of language ability, are frequently used to differentiate normal from pathological cognitive aging. However, language can be particularly difficult to assess in a standardized manner in cross-cultural studies and in patients from different educational and cultural backgrounds. This study examined the effects of age, gender, education and race on performance of two language tests, the animal fluency task (AFT) and the Indiana University Token Test (IUTT). We report population-based normative data on these tests from two combined ethnically divergent, cognitively normal, representative population samples of older adults.
Participants aged ≥65 years from the Monongahela-Youghiogheny Healthy Aging Team (MYHAT) and from the Indianapolis Study of Health and Aging (ISHA) were selected based on (1) a Clinical Dementia Rating (CDR) score of 0; (2) non-missing baseline language test data; and (3) race self-reported as African American or white. The combined sample (n=1885) was 28.1 % African American. Multivariate ordinal logistic regression was used to model the effects of demographic characteristics on test scores.
On both language tests, better performance was significantly associated with higher education, younger age, and white race. On the IUTT, better performance was also associated with female gender. We found no significant interactions between age and sex, and between race and education.
Age and education are more potent variables than are race and gender influencing performance on these language tests. Demographically-stratified normative tables for these measures can be used to guide test interpretation and aid clinical diagnosis of impaired cognition.
neuropsychological tests; norms; cognitive aging; verbal fluency; token test
Previous research has shown that students overestimate the drinking of their peers, and that perceived norms are strongly associated with drinking behavior. Explanations for these findings have been based largely on cross-sectional data, precluding the ability to evaluate the stability of normative misperceptions or to disentangle the direction of influence between perceived norms and drinking. The present research was designed to evaluate (1) the stability of normative misperceptions and (2) temporal precedence of perceived norms and drinking.
Participants were college students (N = 164; 94 women) who completed assessments of perceived norms and reported behavior for drinking frequency and weekly quantity. Most participants (68%) completed the same measures again two months later.
Results indicated large and stable overestimations of peer drinking for frequency and weekly quantity. Results also showed that for weekly quantity, perceived norms predicted later drinking, but drinking also predicted later perceived norms. Results for frequency revealed perceived norms predicted later drinking, but drinking did not predict later perceived norms.
These findings underscore the importance of longitudinal designs in evaluating normative influences on drinking. The present findings suggest that normative misperceptions are stable, at least over a relatively short time period. Findings support a mutual influence model of the relationship between perceived norms and drinking quantity but are more strongly associated with conformity explanations for the relationship between perceived norms and drinking frequency. Results are discussed in terms of implications for prevention interventions.
We investigated alcohol-related sexual risk behavior from the perspective of social norms theory. Adults (N = 895, 62% men) residing in a South African township completed street-intercept surveys that assessed risk and protective behaviors (e.g., multiple partners, drinking before sex, meeting sex partners in shebeens, condom use) and corresponding norms. Men consistently overestimated the actual frequency of risky behaviors, as reported by the sample, and underestimated the frequency of condom use. Relative to actual attitudes, men believed that other men were more approving of risk behavior and less approving of condom use. Both behavioral and attitudinal norms predicted the respondents' self-reported risk behavior. These findings indicate that correcting inaccurate norms in HIV-risk reduction efforts is worthwhile.
Rates of mild cognitive impairment (MCI) have varied substantially, depending on the criteria used and the samples surveyed. The present investigation used a psychometric algorithm for identifying MCI and its’ stability to determine if low cognitive functioning was related to poorer longitudinal outcomes. The Advanced Cognitive Training of Independent and Vital Elders (ACTIVE) study is a multi-site longitudinal investigation of long-term effects of cognitive training with older adults. ACTIVE exclusion criteria eliminated participants at highest risk for dementia (i.e., MMSE<23). Using composite normative for sample- and training- corrected psychometric data, 8.07% of the sample had amnestic impairment, while 25.09% had a non-amnestic impairment at baseline. Poorer baseline functional scores were observed in those with impairment at the first visit, including a higher rate of attrition, depressive symptoms, and self-reported physical functioning. Participants were then classified based upon the stability of their classification. Those who were stably impaired over the five-year interval had the worst functional outcomes (e.g., IADL performance), and inconsistency in classification over time also appeared to be associated increased risk. These findings suggest that there is prognostic value in assessing and tracking cognition to assist in identifying the critical baseline features associated with poorer outcomes.
cognitive impairment; research classification; cognitive aging; longitudinal follow-up
Mild cognitive impairment (MCI) is proposed to be a prodrome to dementia in some older adults. However, the presentation of MCI in the community can differ substantially from clinic-based samples. The aim of the current study is to demonstrate the effects of different operational definitions of MCI on prevalence estimates in community-dwelling older adults. A consecutive series of 200 participants aged 65 and over from the Adult Changes in Thought (ACT) community-based cohort were approached to undergo comprehensive neuropsychological and medical evaluation; 159 were included in the final analyses. Nondemented subjects were categorized using various diagnostic criteria for MCI. In a novel approach, neuropsychological test scores were evaluated using an individualized benchmark as a point of test comparison, as well as traditional methods that entail comparison to age-based normative data. Diagnostic criteria were further subdivided by severity of impairment (1.0 vs. 1.5 standard deviations [sd] below the benchmark) and extent of impairment (based on a single test or an average of tests within a cognitive domain). MCI prevalence rates in the sample were highly dependent on these diagnostic factors, and varied from 11% to 92% of the sample. Older groups tended to show higher prevalence rates, although this was not the case across all diagnostic schemes. The use of an individualized benchmark, less severe impairment cutoff, and impairment on only a single test all produced higher rates of MCI. Longitudinal follow-up will determine whether varying diagnostic criteria improves sensitivity and specificity of the MCI diagnosis as a predictor for dementia.
Age related memory disorders; aging; cognition; Alzheimer's disease; dementia; diagnosis; epidemiology; individual differences; neuropsychological tests; prevalence; normative
Research suggests overlap in brain regions undergoing neurodegeneration in Parkinson's and Alzheimer's disease. To assess the clinical significance of this, we applied a validated Alzheimer's disease-spatial pattern of brain atrophy to patients with Parkinson's disease with a range of cognitive abilities to determine its association with cognitive performance and decline. At baseline, 84 subjects received structural magnetic resonance imaging brain scans and completed the Dementia Rating Scale-2, and new robust and expanded Dementia Rating Scale-2 norms were applied to cognitively classify participants. Fifty-nine non-demented subjects were assessed annually with the Dementia Rating Scale-2 for two additional years. Magnetic resonance imaging scans were quantified using both a region of interest approach and voxel-based morphometry analysis, and a method for quantifying the presence of an Alzheimer's disease spatial pattern of brain atrophy was applied to each scan. In multivariate models, higher Alzheimer's disease pattern of atrophy score was associated with worse global cognitive performance (β = −0.31, P = 0.007), including in non-demented patients (β = −0.28, P = 0.05). In linear mixed model analyses, higher baseline Alzheimer's disease pattern of atrophy score predicted long-term global cognitive decline in non-demented patients [F(1, 110) = 9.72, P = 0.002], remarkably even in those with normal cognition at baseline [F(1, 80) = 4.71, P = 0.03]. In contrast, in cross-sectional and longitudinal analyses there was no association between region of interest brain volumes and cognitive performance in patients with Parkinson's disease with normal cognition. These findings support involvement of the hippocampus and parietal–temporal cortex with cognitive impairment and long-term decline in Parkinson's disease. In addition, an Alzheimer's disease pattern of brain atrophy may be a preclinical biomarker of cognitive decline in Parkinson's disease.
Alzheimer's disease; dementia; mild cognitive impairment; Parkinson's disease; neurodegeneration
1) To report site-specific normative values by age, sex and educational level for four components of the 10/66 Dementia Research Group cognitive test battery; 2) to estimate the main and interactive effects of age, sex, and educational level by site; and 3) to investigate the effect of site by region and by rural or urban location.
Population-based cross-sectional one phase catchment area surveys were conducted in Cuba, Dominican Republic, Venezuela, Peru, Mexico, China and India. The protocol included the administration of the Community Screening Instrument for Dementia (CSI 'D', generating the COGSCORE measure of global function), and the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) verbal fluency (VF), word list memory (WLM, immediate recall) and recall (WLR, delayed recall) tests. Only those free of dementia were included in the analysis.
Older people, and those with less education performed worse on all four tests. The effect of sex was much smaller and less consistent. There was a considerable effect of site after accounting for compositional differences in age, education and sex. Much of this was accounted for by the effect of region with Chinese participants performing better, and Indian participants worse, than those from Latin America. The effect of region was more prominent for VF and WLM than for COGSCORE and WLR.
Cognitive assessment is a basic element for dementia diagnosis. Age- and education-specific norms are required for this purpose, while the effect of gender can probably be ignored. The basis of cultural effects is poorly understood, but our findings serve to emphasise that normative data may not be safely generalised from one population to another with quite different characteristics. The minimal effects of region on COGSCORE and WLR are reassuring with respect to the cross-cultural validity of the 10/66 dementia diagnosis, which uses only these elements of the 10/66 battery.
Many personality assessment inventories provide gender-specific norms to allow comparison of an individual’s standing relative to others of the same gender. In some cases, this means that an identical raw score produces standardized scores that differ notably depending on whether the respondent is male or female. Thus, an important question is whether unisex-normed scores or gender-normed scores more validly assess personality. We examined the gender-normed and unisex-normed scores from the NEO Personality Inventory – Revised (NEO PI-R; Costa & McCrae, 1992) in a large clinical sample, using two measures of personality disorder as validating criteria. Gender-normed scores did not obtain significantly higher correlations. In fact, for two personality disorders, antisocial and narcissistic, gender-normed scores yielded significantly lower correlations, suggesting that personality disorder pathology relates most closely to one’s absolute level of a personality trait rather than one’s standing relative to others of the same gender. We discuss ramifications of this finding for personality research and clinical assessment.
Gender; t-scores; NEO PI-R; FFM; Personality Disorders
Dementia is a cause of disability in later life. Despite the importance of functional status to the diagnosis of dementia, limited information exists on differences in functional limitations by dementia subtype. We conducted a cross-sectional analysis using the Aging, Demographics, and Memory Study (ADAMS) to determine the extent of functional impairment among older adults with dementia due to different etiologies.
The ADAMS sample consisted of 856 individuals aged 71 years and older originally surveyed as part of the Health and Retirement Study. Based on a comprehensive in-person cognitive evaluation, respondents were assigned to diagnostic categories of normal cognition, cognitive impairment not demented, and demented. Dementia subtypes were grouped into three categories: vascular dementia (VaD), Alzheimer’s dementia (AD), and dementia due to other etiologies. For 744 of the 856 respondents, a proxy informant completed a questionnaire asking whether the respondent had difficulty completing instrumental activities of daily living and activities of daily living (ADLs).
Of 744 ADAMS participants, 263 had dementia: 199 (70.5%) with AD, 42 (16.9%) with VaD, and 22 (12.6%) were demented due to other etiologies. After adjustment for demographics, chronic illnesses, and dementia severity, participants with VaD (odds ratio [OR] 5.74; 95% confidence interval [CI] 2.60–12.69) and other etiologies of dementia (OR 21.23; 95% CI 7.25–62.16) were more likely to have greater than or equal to four ADL limitations compared with those with AD.
VaD is associated with significantly more ADL limitations than AD. These physical limitations should be considered when designing adult day care programs, which adequately accommodate the needs of non-AD patients.
Activities of daily living; Instrumental activities of daily living; Disability; Dementia
Scores on the Boston Naming Test (BNT) are frequently lower for African American when compared to Caucasian adults. Although demographically-based norms can mitigate the impact of this discrepancy on the likelihood of erroneous diagnostic impressions, a growing consensus suggests that group norms do not sufficiently address or advance our understanding of the underlying psychometric and sociocultural factors that lead to between-group score discrepancies. Using item response theory and methods to detect differential item functioning (DIF), the current investigation moves beyond comparisons of the summed total score to examine whether the conditional probability of responding correctly to individual BNT items differs between African American and Caucasian adults. Participants included 670 adults age 52 and older who took part in Mayo's Older Americans and Older African Americans Normative Studies. Under a 2-parameter logistic IRT framework and after correction for the false discovery rate, 12 items where shown to demonstrate DIF. Six of these 12 items (“dominoes,” “escalator,” “muzzle,” “latch,” “tripod,” and “palette”) were also identified in additional analyses using hierarchical logistic regression models and represent the strongest evidence for race/ethnicity-based DIF. These findings afford a finer characterization of the psychometric properties of the BNT and expand our understanding of between-group performance.
Boston Naming Test; Item response theory; Differential item functioning; Ethnicity; Race; Bias
The two objectives of this study were (a) to replicate the previous finding of more severe sleep difficulties in a sample of individuals with spinal cord injury (SCI) compared with normative samples, and (b) to examine the associations between aging variables (specifically, chronological age, duration of SCI, age at SCI onset) and the severity of sleep difficulties.
A survey was administered to 620 individuals with SCI that included measures of demographic characteristics and sleep difficulties.
The findings indicated that sleep problems are more common in individuals with SCI than in normative samples. In addition, younger participants in our sample reported more sleep problems than did older participants. Duration of SCI and age at onset, however, were not significantly associated with sleep difficulties.
The analyses used in this study provide a model for examining age effects using concurrent survey data that may be useful for other investigators interested in studying the associations between age-related variables and important health-related domains.
spinal cord injury; sleep problems; aging; multiple regression
Determining mobility status is an important component of any health assessment for older adults. In order for a mobility measure to be relevant and meaningful, normative data are required for comparison to a healthy reference population. The DEMMI is the first mobility instrument to measure mobility across the spectrum from bed bound to functional levels of independent mobility. In this cross-sectional observational study, normative data were obtained for the DEMMI from a population of 183 healthy, community-dwelling adults age 60+ who resided in Vancouver, Canada and Melbourne, Australia. Older age categories had significantly lower DEMMI mobility mean scores (P < 0.05), as did individuals who walked with a mobility aid or lived in semi-independent living (assisted living or retirement village), whereas DEMMI scores did not differ by sex (P = 0.49) or reported falls history (P = 0.21). Normative data for the DEMMI mobility instrument provides vital reference scores to facilitate its use across the mobility spectrum in clinical, research, and policymaking settings.
The objective was to examine various aspects of narcissism in patients admitted to acute psychiatric wards and to compare their level of narcissism to that of an age- and gender-matched sample from the general population (NORM).
This cross-sectional study interviewed 186 eligible acute psychiatric patients with the Brief Psychiatric Rating Scale (BPRS) and the Global Assessment of Functioning (GAF). The patients filled in the Narcissistic Personality Inventory-21 item version (NPI-21), The Hospital Anxiety and Depression Scale (HADS) and the Rosenberg Self-Esteem Scale. High and low narcissism was defined by the median of the total NPI-21 score. An age- and gender-matched control sample from the general population also scored the NPI-21 (NORM).
Being male, involuntary admitted, having diagnosis of schizophrenia, higher self-esteem, and severe violence were significantly associated with high narcissism, and so were also low levels of suicidality, depression, anxiety and GAF scores. Severe violence and high self-esteem were significantly associated with high narcissism in multivariable analyses. The NPI-21 and its subscales showed test-retest correlations ≥0.83, while the BPRS and the HADS showed lower correlations, confirming the trait character of the NPI-21. Depression and suicidality were negatively associated with the NPI-21 total score and all its subscales, while positive association was observed with grandiosity. No significant differences were observed between patients and NORM on the NPI-21 total score or any of the NPI subscales.
Narcissism in the psychiatric patients was significantly associated with violence, suicidality and other symptoms relevant for management and treatment planning. Due to its trait character, use of the NPI-21 in acute psychiatric patients can give important clinical information. The similar level of narcissism found in patients and NORM is in need of further examination.
The CLOX is a clock drawing test used to screen for cognitive impairment in older adults, but there is limited normative data for this measure. This study presents normative data for the CLOX derived from a diverse sample of 585 community-dwelling older adults with complete cognitive data at baseline and 4-year follow-up. Participants with evidence of baseline impairment or substantial 4-year decline on the Mini-Mental State Examination were excluded from the normative sample. Spontaneous clock drawing (CLOX1) and copy (CLOX2) performances were stratified by age group and reading ability from the Wide Range Achievement Test, 3rd edition (WRAT-3). Lowest mean CLOX scores were observed for the oldest age group (75+ years old) with the lowest WRAT-3 reading scores. For all groups, average scores were higher for CLOX2 than CLOX1. These normative data may be helpful to clinicians and researchers for interpreting CLOX performance in older adults with diverse levels of reading ability.
Normative data; Clock drawing test; Reading ability; Older adults; Aging
Gait performance is widely evaluated to assess health status in older adult populations. While several investigators have presented normative values for spatiotemporal gait parameters drawn from older adult populations, the literature has been void of large-scale cohort studies, which are needed in order to provide quantitative, normative gait data in persons with Parkinson’s disease. The aim of this investigation was to provide reference values for clinically important gait characteristics in a large sample of ambulatory persons with Parkinson’s disease to aid both clinicians and researchers in their evaluations and treatments of gait impairment.
Gait performance was collected in 310 individuals with idiopathic Parkinson’s disease as they walked across a pressure sensitive walkway. Fourteen quantitative gait parameters were measured and evaluated with respect to Hoehn and Yahr disease staging and gender. Disease duration and age were controlled for in all analyses. Individuals with the greatest Parkinson’s disability walked significantly slower with shorter steps and stride lengths than the mild and moderately affected groups. Further, the most affected patients spent more time with both feet on the ground, and walked with a wider base of support than the moderately disabled patients. No differences were detected between the mild and moderate disability groups on any of the gait parameters evaluated.
Reference values for 14 gait parameters in a large cohort of ambulatory patients with Parkinson’s disease are provided and these may be highly useful for assessing and interpreting an individual’s gait dysfunction. It is important for clinicians and researchers to appreciate the lack of change in quantitative parameters as PD patients move from mild to moderate gait impairment.
To examine the association between men’s conformity to masculine norms and depression.
University family practice clinic in Vancouver, BC.
Male patients, 19 years of age and older (N = 97).
Main outcome measures
The relationships among patients’ scores on the Brief Symptom Inventory–18 depression subscale, Gotland Male Depression Scale, and Conformity to Masculine Norms Inventory, and whether or not patients were prompted to discuss emotional concerns with their physicians after completing these screening tests.
Conformity to masculine norms was significantly associated with depression as assessed by the male depression screen (P = .039), but not with the screen that assessed typical depressive symptoms (P = .068). Men, regardless of their degree of masculinity or distress, overwhelmingly did not disclose emotional concerns to their physicians, even if the content of their distress involved suicidal thoughts.
Male depression screens might capture aspects of depression associated with masculine gender socialization that are not captured by typical measures of depression. Given the tendency of men to not disclose emotional distress to their family physicians, potentially high-risk cases could be missed without direct inquiry by clinicians.
Self-administered by spouses and other collateral informants, the nationally normed Older Adult Behavior Checklist (OABCL) provides standardized data on diverse aspects of older adult psychopathology and adaptive functioning. We tested the validity of the Older Adult Behavior Checklist (OABCL) scale scores in terms of associations with diagnoses of dementia of the Alzheimer’s type (DAT) and mood disorders (MD) and with 9 measures of psychopathology, cognitive performance, and adaptive functioning.
Informants completed OABCLs for 727 60- to 97-year-olds recruited from a memory disorders clinic, geriatric psychiatry clinic, and community–dwelling seniors. OABCL scale scores were tested for associations with DAT and MD diagnoses, as well as with scores on the Neuropsychiatric Inventory, Mini-Mental State Exam (MMSE), Clock Drawing Test, Alzheimer’s Disease Assessment Scale, Geriatric Depression Scale, Clinical Dementia Rating, Dementia Severity Rating Scale, Trail Making Test Part A, and Instrumental Activities of Daily Living.
OABCL scales had medium to large correlations with the 9 other indices of functioning and significantly augmented MMSE discrimination between patients with DAT vs. MD. OABCL scales also discriminated significantly between patients diagnosed with DAT vs. MD and both these groups vs. nonclinical subjects.
Multiple OABCL scales had medium to large associations with diverse indices of functioning based on other kinds of data. The nationally normed OABCL provides new ways to integrate informant and self-report data to improve assessment of older adults. Specifically, the OABCL can provide discrimination between those who qualify for diagnoses of DAT vs. MD vs. neither diagnosis.
Older Adult Behavior Checklist; Mini-Mental State Exam; Dementia of the Alzheimer’s Type; Mood Disorders; Neuropsychiatric Inventory
There is increasing evidence that depressive symptoms are associated with the development of cognitive impairment and dementia in late life. We sought to examine whether depression increased the risk of incident cognitive impairment in a longitudinal study of older women.
observational study, up to 6 examinations spanning up to 9 years.
university-based Division of Geriatric Medicine
community-based sample of 436 older, non-demented women
Participants were followed with regular medical and neuropsychiatric evaluations. Cognitive assessment included episodic immediate and delayed memory, psychomotor speed, and executive functioning. Participants were characterized as having incident impairment on a cognitive test when scores fell below the tenth percentile on age-adjusted norms. Baseline depressive symptoms were measured using the Geriatric Depression Scale (GDS) (30-item). Discrete-time Cox Proportional hazards regression with generalized linear models were used to determine whether baseline risk factors predicted incident impairment on each cognitive test, defined as performance below the tenth percentile on age-adjusted norms.
Baseline GDS was highly associated with incident impairment on all cognitive tests (p <.03). These associations were unaffected by vascular conditions except diabetes, which was associated with incident impairment in delayed recall and psychomotor speed.
These data suggest that depression may be risk factors for cognitive decline, and thus a potential target for diagnostic and therapeutic interventions.
cognitive decline; depression; cognitive impairment; Mild Cognitive Impairment
The prevalence and incidence of dementia are low in Nigeria, but high among African-Americans. In these populations there is a high frequency of the risk-conferring APOE-e4 allele, but the risk ratio is less than in Europeans. In an admixed population of older Cubans we explored the effects of ethnic identity and genetic admixture on APOE genotype, its association with dementia, and dementia prevalence.
A cross-sectional catchment area survey of 2928 residents aged 65 and over, with a nested case-control study of individual admixture. Dementia diagnosis was established using 10/66 Dementia and DSM-IV criteria. APOE genotype was determined in 2520 participants, and genetic admixture in 235 dementia cases and 349 controls.
Mean African admixture proportions were 5.8% for 'white', 28.6% for 'mixed' and 49.6% for 'black' ethnic identities. All three groups were substantially admixed with considerable overlap. African admixture was linearly related to number of APOE-e4 alleles. One or more APOE-e4 alleles was associated with dementia in 'white' and 'black' but not 'mixed' groups but neither this, nor the interaction between APOE-e4 and African admixture (PR 0.52, 95% CI 0.13-2.08) were statistically significant. Neither ethnic identity nor African admixture was associated with dementia prevalence when assessed separately. However, considering their joint effects African versus European admixture was independently associated with a higher prevalence, and 'mixed' or 'black' identity with a lower prevalence of dementia.
APOE genotype is strongly associated with ancestry. Larger studies are needed to confirm whether the concentration of the high-risk allele in those with African ancestry is offset by an attenuation of its effect. Counter to our hypothesis, African admixture may be associated with higher risk of dementia. Although strongly correlated, effects of admixture and ethnic identity should be distinguished when assessing genetic and environmental contributions to disease risk in mixed ancestry populations.
Interpretations of profile and preference based measure scores can differ. Profile measures often use a norm-based scoring algorithm where each scale is scored to have a standardized mean and standard deviation, relative to the general population scores/norms (i.e., norm-based). Preference-based index measures generate an overall scores on the conventional scale in which 0.00 is assigned to dead and 1.00 is assigned to perfect health. Our objective was to investigate the interpretation of norm-based scoring of generic health status measures in a population of adults with type 1 diabetes by comparing norm-based health status scores and preference-based health-related quality of life (HRQL) scores.
Data were collected through self-complete questionnaires sent to patients with type 1 diabetes. The RAND-36 and the Health Utilities Index Mark 3 (HUI3) were included.
A total of 216 (61%) questionnaires were returned. The respondent sample was predominantly female (58.8%); had a mean (SD) age of 37.1 (14.3) years and a mean duration of diabetes of 20.9 (12.4) years. Mean (SD) health status scores were: RAND-36 PHC 47.9 (9.4), RAND-36 MHC 47.2 (11.8), and HUI3 0.78 (0.23). Histograms of these scores show substantial left skew. HUI3 scores were similar to those previously reported for diabetes in the general Canadian population. Physical and mental health summary scores of the RAND-36 suggest that this population is as healthy as the general adult population.
In this sample, a preference-based measure indicated poorer health, consistent with clinical evidence, whereas a norm-based measure indicated health similar to the average for the general population. Norm-based scoring measure may provide misleading interpretations in populations when health status is not normally distributed.
Some (but not all) epidemiological studies have noted faster rates of progression in high education patients with Alzheimer's disease (AD), which has been attributed to harbouring/tolerating a higher pathological burden at the time of clinical dementia for subjects with higher education. We wanted to assess the relationship between education and rates of decline in AD.
During the course of a community based multiethnic prospective cohort study of individuals aged ⩾65 years living in New York, 312 patients were diagnosed with incident AD and were followed overall for 5.6 (up to 13.3) years. The subjects received an average of 3.7 (up to 9) neuropsychological assessments consisting of 12 individual tests. With the aid of a normative sample, a standardised composite cognitive score as well as individual cognitive domain scores were calculated. Generalised estimating equation models were used to examine the association between education and rates of cognitive decline.
Composite cognitive performance declined by 9% of a standard deviation per year. Rates of decline before and after AD incidence were similar. For each additional year of education there was 0.3% standard deviation lower composite cognitive performance for each year of follow up. The association between higher education and faster decline was noted primarily in the executive speed (0.6%) and memory (0.5%) cognitive domains and was present over and above age, gender, ethnicity, differential baseline cognitive performance, depression, and vascular comorbidity.
We conclude that higher education AD patients experience faster cognitive decline.
Alzheimer's disease; cognitive decline; cognitive reserve; education; incidence