Trajectory classes of depressive symptoms in a community sample of older adults

OBJECTIVE

To identify trajectories of depressive symptoms in older community residents.

METHOD

Depressive symptomatology, based on a modified Center for Epidemiological Studies-Depression scale, was obtained at years 0, 3, 6, and 10, in the Duke Established Populations for Epidemiologic Studies of the Elderly (n = 4162). Generalized growth mixture models identified the latent class trajectories present. Baseline demographic, health, and social characteristics distinguishing the classes were identified using multinomial logistic regression.

RESULTS

Four latent class trajectories were identified. Class 1 - stable low depressive symptomatology (76.6% of the sample); class 2 - initially low depressive symptomatology, increasing to the subsyndromal level (10.0%); class 3 - stable high depressive symptomatology (5.4%); class 4 - high depressive symptomatology improving over 6 years before reverting somewhat (8.0%). Class 1 was younger, male gender, with better education, health, and social resources, in contrast to class 3. Class 2 had poorer cognitive functioning and higher death rate. Class 4 had better health and social resources.

CONCLUSION

Reduction in high depressive symptomatology is associated with more education, better health, fewer stressful events, and a larger social network. Increasing depressive symptomatology is accompanied by poorer physical and cognitive health, more stressful life events, and greater risk of death.

Increased health burden associated with comorbid depression in older Brazilians with diabetes

BACKGROUND

The health burden associated with comorbid depression and diabetes in older community residents in middle income countries is unclear.

METHODS

Data came from a statewide representative sample (N = 6963, age ≥ 60) in Brazil. Controlled polytomous logistic regression was used to determine whether four mutually exclusive groups (all possible combinations of the presence or absence of depression and diabetes) differed in sociodemographic characteristics, social resources, health behaviors, and selected health conditions.

RESULTS

While 2.37% were expected to have comorbid depression/diabetes given sample base rates (depression: 20.92% [1457/6963]; diabetes: 11.35% [790/6959]), comorbidity was present in 3.62% (52.5% beyond expectation; P<0.0001; OR = 1.58, 95% Confidence Interval 1.29-1.95). Depression without diabetes was reported by 17.3%, and diabetes without depression by 7.7%. In controlled analyses, the depression group had poorer socioeconomic status and health behaviors, and a greater likelihood of vascular, respiratory, and musculoskeletal problems than the diabetes group. Vascular, respiratory, and urinary problems were exacerbated in comorbid depression/diabetes; the comorbid group was also more likely to be female and younger.

LIMITATIONS

Cross-sectional design.

CONCLUSIONS

To our knowledge, this is the first study that explicitly reports on all four possible depression/diabetes combinations in an older representative community-resident sample, using controlled analyses to identify unique associations with sociodemographic characteristics and other health conditions. The burden of comorbid depression/diabetes in Brazil, a middle income country, appears to be comparable to that found in higher income countries. So, similarly, depression without diabetes had a greater odds of adverse sociodemographic and health conditions than diabetes without depression; comorbid depression/diabetes was more likely in women and young elderly, and the odds of vascular, respiratory, and urinary conditions was increased significantly. Attention to comorbid depression/diabetes as a unique entity is needed.

Modeling association in longitudinal binary outcomes: a brief review

In order to better understand aging, longitudinal studies are run in which participants are evaluated repeatedly and selected end-points (e.g., score on a cognitive screen, falls, occurrence/reoccurrence of a condition) are examined. The objective of the present paper is primarily to describe the methods available that take into account correlation between binary outcomes, and in particular to model the association of binary outcomes after controlling for covariates by using an implementation of generalized estimating equations (GEE) called 'alternating logistic regression' (ALR). In GEE, association within longitudinal outcomes is accounted for but not estimated. Alternating logistic regression, however, basically enables simultaneous estimation of pair-wise odds ratios of outcomes within a cluster, while accounting for the dependence of the outcome on covariates. A sub-sample (n=2458) from a community-based sample of Duke Established Populations for Epidemiologic Studies of the Elderly is used. In the example used here, logistic regression using GEE and ALR is used to model binary outcomes at three time points (baseline, three and six years later) and to control for covariates in a representative community-based sample 65 years of age and older (n=2458). The outcomes indicate any problem versus no problem on a five-item activities of daily living (ADL) scale in a community sample. The ALR model, however, provides insight into decline in ADL from baseline to each of the time-points whereas GEE does not. In both controlled and uncontrolled analyses, decline in ADL over three and six-year intervals (baseline to three years later, baseline to six years and three years post-baseline to six years post-baseline) is significant.

Comparison of methods for analyzing longitudinal binary outcomes: cognitive status as an example

Longitudinal data generate correlated observations. Ignoring correlation can lead to incorrect estimation of standard errors, resulting in incorrect inferences of parameters. In the example used here, standard logistic regression, a population-averaged (PA) model fit using generalized estimating equations (GEE), and random-intercept models are used to model binary outcomes at baseline, three and six years later. The outcomes indicate cognitive impairment versus no cognitive impairment in a sample of community dwelling elders. The models include both time-invariant (age, gender) and time-varying (time, interactions with time) covariates. The absolute estimates from random-intercept models are larger than those of both standard logistic and GEE models. Compared to the model fit using GEE that accounts for time dependency, standard logistic regression models overestimate standard errors of time-varying covariates (such as time, and time by problems with activities of daily living), and underestimate the standard errors of time-invariant covariates (such as age and gender). The standard errors from the random-intercept model are larger than those from logistic regression and GEE models. The choice of models, GEE or random-intercept, depends on the research question and the nature of the covariates. Population-averaged methods are appropriate when between-subjects effects are of interest, and random-effects are useful when subject-specific effects are important.

Alternative statistical approaches to identifying dementia in a community-dwelling sample

Little attention has been paid to examining the extent to which alternative statistical models may facilitate identification of persons with dementia. Using a sub-sample of the Duke Established Populations for Epidemiologic Studies of the Elderly, two analytical approaches were compared: logistic regression (which focuses on identifying specific characteristics predictive here of dementia), and recursive partitioning methods using tree-based models (which permit identification of the characteristics of those groups with high dementing disorder). In the stepwise multiple logistic regression model which included as potential predictors, gender, age, history of chronic health conditions, scales of basic and instrumental activities of daily living (IADL), and cognitive status, only IADL and cognitive status were significant predictors, with cognitive status the single most important factor. The classification tree approach, which permits identification of the characteristics of those groups with particularly high dementia rates, identified cognitive status as the most important criterion for dementia (as did logistic regression analysis). Among those without cognitive impairment, older age was a risk factor, confirming findings consistently reported in the literature. Among the cognitively impaired, IADL was an important risk factor. Those with five or more IADL problems were further classified into two risk groups, based on number of ADL problems. While classification tree analysis encourages identification of groups at risk, logistic regression encourages targeting of specific characteristics.

Epidemiology of over-the-counter drug use in community dwelling elderly: United States perspective

Among US community dwelling individuals aged > or = 65 years, about as many persons take nonprescription drugs as take prescription drugs. A review of US data from the last 2 decades indicates that the average number of over-the-counter (OTC) drugs taken daily is around 1.8, but varies with geographical area (highest in the Midwest) and race/ethnicity (lowest use among Hispanics, followed by African Americans. and highest use among Whites). Use has consistently been found to be higher in women than in men. While OTC use appears to be increasing over time, it also decreases with increase in age. The most common OTC classes used are analgesics, laxatives and nutritional supplements. Our ability to explain or to predict OTC use and change in use is poor, and further studies, particularly on use by elderly individuals of minority races, are needed.

The relationship of APOE genotype to cognitive functioning in older African-American and Caucasian community residents

OBJECTIVES

To determine whether cognitive decline associated with the apolipoprotein E (APOE) epsilon4 allele is different in older African Americans than it is in Caucasians.

DESIGN

Performance on a brief screen of cognitive functioning was examined at baseline (N = 1,891) and 4 years later (N = 1,389) to determine the extent to which the presence of APOE epsilon4 affected level of and change in performance, and whether this differed as a function of race, age, initial score, and change in score.

SETTING

Five adjacent counties in the Piedmont area of North Carolina.

PARTICIPANTS

In 1986, a stratified random household sample of community residents age 65 and older (n = 4,162; 54% African-American, 45% Caucasian, 1% other race) formed the Duke Established Populations for Epidemiologic Studies of the Elderly. Of those available at the sixth annual wave, 76% were genotyped, with 1,891 providing baseline data on this wave, and the available survivors (n = 1,389) providing longitudinal data 4 years later.

MEASUREMENTS

The Short Portable Mental Status Questionnaire (SPMSQ), a brief screen of cognitive functioning, was administered to all subjects on both occasions. We examined score at baseline and cognitive decline (i.e., increase of 2+ errors) at follow-up. Control measures included demographic characteristics, health behaviors, health and functional status, and medication use. APOE status was coded as epsilon4 present versus absent.

RESULTS

APOE epsilon4 was significantly and uniquely related to lower score at baseline and significantly increased the odds of cognitive decline by 59%. There was no statistically significant interaction between APOE epsilon4 and age, race, initial SPMSQ score, or SPMSQ score at follow-up.

CONCLUSION

APOE epsilon4 is modestly, if significantly, related to poorer cognitive functioning and to decline in cognitive functioning. No differences were found by age or race in this community representative sample.

In-home assessment of dementia by nurses: experience using the CERAD evaluations. Consortium to Establish a Registry for Alzheimer's Disease

PURPOSE OF STUDY

To maximize respondent participation in a study of the prevalence, incidence, and natural history of dementia.

DESIGN AND METHODS

Clinical research nurses were trained to carry out evaluations for dementia in the home. We describe the assessment and training procedures used and note the advantages and drawbacks of this approach.

RESULTS

Nurse identification of the presence of dementia agreed well with that of medical specialists (kappa = 0.84), but was slightly poorer regarding type of dementia (kappa = 0.71).

IMPLICATIONS

Use of nurses for such activity need not be limited to epidemiological studies, but is relevant also in clinical practice.

Performance of elderly African American and White community residents on the CERAD Neuropsychological Battery

The CERAD Neuropsychological Battery, includes 7 measures: Verbal Fluency; Modified Boston Naming; Mini-Mental State: Word List Learning, Recall and Recognition; Constructional Praxis. It was originally developed to evaluate patients with a clinical diagnosis of Alzheimer's disease, but is increasingly used in epidemiological studies of the incidence and prevalence of dementia in the elderly. The current study reports norms for African American and White representative community residents 71 years of age and older in North Carolina, and compares performance with that of African Americans in Indianapolis and with Whites in the Monongahela Valley, Pennsylvania. For all 3 studies, increased education and younger age was related to better performance on each of the 7 measures. Sex differences, when present, tended to favor women. Although on average African Americans performed more poorly than Whites, with demographic characteristics controlled, no significant racial differences were found in the North Carolina sample. Both African American and White participants in North Carolina performed more poorly than their racial counterparts in the other 2 studies, possibly because of selection-induced differences in health and educational status. Nevertheless, the use of an identical evaluation battery, such as the CERAD neuropsychologic instrument, facilitates comparisons not otherwise possible, and should be encouraged.

Impact of estrogen use on decline in cognitive function in a representative sample of older community-resident women

The authors investigated whether postmenopausal estrogen use helps to maintain cognitive function; a brief screen, the Short Portable Mental Status Questionnaire (SPMSQ), was used. Information was gathered from a stratified, random sample of 1,907 African-American and White women (aged 65-100 years) participating in the longitudinal Duke Established Populations for Epidemiologic Studies of the Elderly project carried out in five urban and rural counties of North Carolina. All women were cognitively unimpaired in 1986-1987 and were evaluated 3 and 6 years later. Decline in cognitive function was measured as an increase of two or more errors on the SPMSQ and crossing of an SPMSQ threshold indicative of cognitive impairment. Recency and continuity of estrogen use were measured. Univariate analyses indicated that recent (crude odds ratio = 0.42, 95% confidence interval: 0.21, 0.86) and continuous (crude odds ratio = 0.32, 95% confidence interval: 0.13, 0.81) estrogen use reduced the risk of cognitive decline but not of cognitive impairment. After adjustment for demographic and health characteristics, protective effects became nonsignificant. While postmenopausal use of estrogen may be protective for Alzheimer's disease, current findings based on a brief cognitive screen suggest that it is not protective for cognitive decline related to aging.

Inappropriate drug use among community-dwelling elderly

This study examined inappropriate drug use defined by updated criteria among respondents in the second and third in-person waves of the Duke Established Populations for Epidemiologic Studies of the Elderly. Information about sociodemographics, health status, access to health care, and drug use was determined by in-home interviews. Drug use was coded for therapeutic class and appropriateness by applying explicit criteria. Among participants, 27% of the second and 22.5% of the third in-person wave took one or more inappropriate agents. Of these drugs, the most common therapeutic classes were central nervous system and cardiovascular. Longitudinal multivariate analyses found that persons taking several prescription drugs, those having continuity of care, those who previously took inappropriate drugs, and those with many health visits were most likely (p<0.05) to use inappropriate drugs. We conclude that inappropriate drug use is common among community-dwelling elderly.

Comorbidity of five chronic health conditions in elderly community residents: determinants and impact on mortality

BACKGROUND

Comorbidity is common in elderly persons. Its extent, correlates, and life-threatening impact in representative community residents are unclear.

METHODS

Self-reported information of physician-diagnosed coronary artery disease (CAD), cerebrovascular disease (CVD), diabetes, and cancer was obtained annually between 1986-87 and 1992-93, and hypertension was obtained triennially from the participants of the Duke Established Populations for Epidemiologic Studies of the Elderly, a stratified multistage sample of 4,126 Black and White community residents aged 65-100, living in a five-county area of North Carolina. Date of death was obtained from death certificates identified through search of the National Death Index. Statistical procedures included descriptive statistics, logistic regression, and survival analysis.

RESULTS

Of this sample, 57% reported hypertension, 20% diabetes, 15% CAD, 9% cancer, and 9% CVD; 29% reported none of these conditions, whereas 29% reported two or more. Demographic characteristics were not related to comorbidity with CVD or cancer. Increased education tended to be protective. The effect of age, gender, and race varied with condition. At baseline there was substantial comorbidity among hypertension, CAD, CVD, and diabetes, but not with cancer. Hypertension, CVD, and diabetes were risk factors for CAD, whereas diabetes was a risk factor for CVD. After controlling for demographic characteristics, all health conditions except hypertension were predictive of 6-year mortality, as was the presence of comorbidity.

CONCLUSION

We found significant comorbidity in older persons who have hypertension, CAD, CVD, or diabetes; particular risk of developing comorbidity, particularly CAD, among those with hypertension, CVD, and diabetes; and risk of CVD in those with diabetes. With the exception of hypertension, these conditions, and comorbidity per se, are life-threatening.

The effect of race and health-related factors on naming and memory. The MacArthur Studies of Successful Aging

OBJECTIVES

The purpose of the analyses was to examine the impact of health-related variables on race differences in neuropsychological functioning (Boston Naming Task).

METHODS

Using cross-sectional data from the MacArthur Successful Aging Study, the authors examined the relationship of demographic characteristics, health status, health habits, physical functioning, and speed of performance to naming and incidental recall of items from the Boston Naming Task. Participants were 1,175 healthy African American and European American older persons 70 to 79 years old.

RESULTS

Regression analyses indicated that although race differences persisted for confrontational naming after controlling for demographic and health factors, there was no effect due to race for incidental recall scores or for savings scores for recall.

DISCUSSION

The racial differences found in test performance may reflect differences in cultural appropriateness of the material rather than differences in ability.

Determinants of attrition in a natural history study of Alzheimer disease

The aim of the present study was to identify determinants of attrition in a natural history study of a tertiary care sample of patients with Alzheimer disease (AD) and control subjects. A longitudinal study was performed with 978 patients with AD and 466 control subjects age 50 years and older enrolled at 25 sites of the Consortium to Establish a Registry for Alzheimer's Disease between January 1987 and January 1992; subjects were followed annually for up to 78 months. Both descriptive statistics and polytomous logistic regressions were run to identify determinants of attrition. Of the 1,444 subjects enrolled, 10.5% dropped out after initial evaluation, 31.0% provided at least two waves of data, and 58.4% provided complete follow-up. Inadequate involvement by the site, non-white status, and patient's spouse not enrolled in the study were predictive of dropout; cessation of participation because of death (which may have precluded dropout) predicted continuation in the study. Age, level of education, severity of dementia, and rapidity of progression of disease did not predict dropout. Level-of-site commitment was the most significant determinant of continued participation in this natural history study of AD, followed by white race, and the inclusion of both husband and wife where one is a patient and the other a control subject.

Variability in annual Mini-Mental State Examination score in patients with probable Alzheimer disease: a clinical perspective of data from the Consortium to Establish a Registry for Alzheimer's Disease

OBJECTIVE

To determine the variability in annual Mini-Mental State Examination scores of patients with Alzheimer disease enrolled in the Consortium to Establish a Registry for Alzheimer's Disease (CERAD).

PATIENTS

A total of 372 patients with probable Alzheimer disease with 1 or more years of follow-up.

SETTING

Twenty-one CERAD clinical sites throughout the United States.

RESULTS

An average annual decline of 3.4 points in CERAD patients returning for longitudinal reassessments was close to the SD of the measurement error of 2.8 points for the Mini-Mental State Examination. There was wide variability in individual rates of decline. Even with 4 years of follow-up, 15.8% of the patients had no clinically meaningful decline in Mini-Mental State Examination score (defined as a change in initial score >3, ie, 1 SD of measurement error). Validity of measurements of the rate of change in Mini-Mental State Examination scores improved with longer observation intervals and was reliable for most patients when observations were separated by 3 or more years.

CONCLUSIONS

Although the Mini-Mental State Examination is a useful screening instrument to assess level of cognitive function, it has limited value in measuring the progression of Alzheimer disease in individual patients for periods less than 3 years because of a large measurement error and substantial variation in change in annual score.

Comparison of Lewy body variant of Alzheimer's disease with pure Alzheimer's disease: Consortium to Establish a Registry for Alzheimer's Disease, Part XIX

OBJECTIVE

To compare the clinical, neuropsychological, and neuropathologic findings in patients with AD alone with those in patients with the Lewy body variant of AD (LBV).

BACKGROUND

Prior studies indicate that patients with LBV not only have distinct clinical and neuropsychological differences from those with AD alone, but have a poorer prognosis with shorter survival time.

METHODS

The authors evaluated 74 patients with autopsy-confirmed AD alone and 27 patients with LBV, and compared demographic characteristics and clinical, neuropsychological, and neuropathologic findings.

RESULTS

The two groups of patients were equivalent with respect to age at time of entry into the study, years of education, and sex. Two or more extrapyramidal clinical manifestations were found in 44% of patients with LBV, compared with 16% of patients with AD alone (p = 0.02). Duration of survival after entry into the study was similar in both groups, with a mean survival of 3.6 (+/-2.1) years for AD alone versus 3.8 (+/-1.9) years for LBV. Of the various neuropsychological tests administered at the last Consortium to Establish a Registry for Alzheimer's Disease evaluation, only delayed recall of a learned word list was significantly different in the two groups, with 32% of patients with LBV versus 15% of patients with AD alone recalling any items (p = 0.04). Neuropathologic findings confirmed those of previous studies and showed that neurofibrillary tangles were significantly less frequent in the neocortex of patients with LBV than in those with AD alone.

CONCLUSION

Compared with patients with AD alone, those with LBV had a greater frequency of extrapyramidal manifestations, somewhat better recall on a selected memory task at their final evaluation, and a significantly lower frequency of neocortical neurofibrillary tangles at autopsy. There were no differences between the two groups, however, in survival time from entry into the study.

Development of an activities of daily living scale to screen for dementia in an illiterate rural older population in India

OBJECTIVE

to develop a measure of activities of daily living appropriate for use in assessing the presence of dementia in illiterate rural elderly people in India.

DESIGN

identification of relevant items, pre-testing of items and refinement of administrative procedures and scoring in four successive groups of 30 subjects each, pilot testing in a group of 100 subjects comparable to those for whom the measure is intended, administration to a representative sample of 387 people aged 55 and older, and assessment of the reliability of the final measure.

SETTING AND SUBJECTS

age-stratified random sample of older men and women in rural areas of Ballabgarh, Northern India.

RESULTS

the original pool of 35 items covering mobility, instrumental and personal care activities was reduced to an 11-item unidimensional scale (to which an additional item on mobility was added) with internal consistency (Cronbach's alpha)=0.82, perfect inter- and intra-rater reliability, test-retest reliability (intraclass correlation)=0.82 (any disability) and 0.92 (unable to perform for 'mental' reasons). Women, older subjects, the totally illiterate and subjects with poorer cognitive function performed significantly more poorly (P < or = 0.02 for all). PRODUCT: a brief, reliable and valid activities of daily living measure, with norms, which is appropriate for use in assessing dementia in illiterate rural elderly people in India.

Equivalence of two screens of cognitive functioning: the Short Portable Mental Status Questionnaire and the Orientation-Memory-Concentration test

OBJECTIVE

To determine the equivalence of two screens of cognitive functioning: the Short Portable Mental Status Questionnaire (SPMSQ) and the Orientation-Memory-Concentration (OMC) test.

DESIGN

The design was cross-sectional and longitudinal.

SETTING

Four rural and one urban county in the Piedmont region of North Carolina (n = 3210).

PARTICIPANTS

A stratified random cluster sample (n = 3210) of people 68 years of age and older.

MEASUREMENTS

SPMSQ and OMC at the fourth wave of the Duke Established Populations for Epidemiologic Studies of the Elderly (EPESE); disability, depression, and death measurements from the fourth through seventh waves of EPESE; demographic characteristics.

RESULTS

On the SPMSQ and the OMC (r = .80), 15.3% and 38.4%, respectively, of those tested were rated cognitively impaired. Poorer scores were associated with older age, black race, and less education. These associations were attenuated on the dichotomized SPMSQ but not on the OMC. Both measures predicted disability and depressive symptomatology currently and 3 years hence and death.

CONCLUSIONS

The SPMSQ and OMC, although highly correlated, are not equivalent. Association with race and education are greater for the OMC, whereas an association with age exists for both measures. The milder level of impairment identified by the OMC increases predictive capacity.

Benzodiazepine use and cognitive function among community-dwelling elderly

OBJECTIVE

To evaluate the relation between benzodiazepine use and cognitive function among community-dwelling elderly.

METHODS

This prospective cohort study included 2765 self-reporting subjects from the Duke Established Populations for Epidemiologic Studies of the Elderly. The subjects were cognitively intact at baseline (1986-1987) and alive at follow-up data collection 3 years later. Cognitive function was assessed with the Short Portable Mental Status Questionnaire (unimpaired versus impaired and change in score) and on the basis of the number of errors on the individual domains of the Orientation-Memory-Concentration Test. Benzodiazepine use was determined during in-home interviews and classified by dose, half-life, and duration. Covariates included demographic characteristics, health status, and health behaviors.

RESULTS

After control for covariates, current users of benzodiazepine made more errors on the memory test (beta coefficient, 0.35; 95% confidence interval [CI], 0.10 to 0.61) than nonusers. Further assessment of the negative effects on memory among current users suggested a dose response in which users taking the recommended or higher dose made more errors (beta coefficient, 0.57; 95% CI, 0.26 to 0.88) and a duration response in which long-term users made more errors (beta coefficient, 0.39; 95% CI, 0.05 to 0.73) than nonusers. Users of agents with long half-lives and users of agents with short half-lives both had increased memory impairment (beta coefficient, 0.32; 95% CI, 0.01 to 0.64 and beta coefficient, 0.38; 95% CI, 0.02 to 0.75, respectively) relative to nonusers. Previous benzodiazepine use was unrelated to memory problems, and current and previous benzodiazepine use was unrelated to level of cognitive functioning as measured with the other 4 tests.

CONCLUSIONS

The results suggested that current benzodiazepine use, especially in recommended or higher doses, is associated with worse memory among community-dwelling elderly.

Developing a summary measure of medical status

Health status surveys and assessments typically obtain detailed information on specific physical health conditions. While such specific details are important, it is frequently also valuable to have a summarized evaluation of medical conditions which can be used to compare subjects, or for statistical analyses. Using data from the Duke Established Populations for Epidemiologic Studies of the Elderly survey, we indicate how to obtain a weighted sum of chronic medical conditions. Like the sum of the same conditions, it explains variance in selected measures of health service use and health status, in some instances making a contribution beyond that of the summed measure. It is a significantly better predictor of mortality within six years.

Private health insurance coverage and disability among older Americans

OBJECTIVES

This study examines the relationship between the lack of private supplemental health insurance coverage and the development of disability among adults aged 65 and older.

METHODS

Data are from the baseline and six follow-up waves of the Duke Established Populations for Epidemiologic Studies of the Elderly survey (N = 4,000). Discrete-time hazard models were used to estimate the impact of insurance coverage and other risk factors on the incidence of disability among those unimpaired at baseline.

RESULTS

Controlling for education, income, and other potential confounders, the odds of developing disability were 35-49% higher among those without private coverage. Insurance coverage also statistically explained part of the increased risk of disability among low-income persons.

DISCUSSION

The results indicate that changes in health insurance coverage as well as in individual behaviors may be needed to reduce disability generally and disability among the socioeconomically disadvantaged, in particular.

Cerebral infarcts in patients with autopsy-proven Alzheimer's disease: CERAD, part XVIII. Consortium to Establish a Registry for Alzheimer's Disease

OBJECTIVE

To study the relation between cerebral infarction and clinical and neuropsychologic manifestations in patients with autopsy-proven Alzheimer's disease (AD) enrolled in the Consortium to Establish a Registry for Alzheimer's Disease (CERAD).

BACKGROUND

Prior studies report that subjects with neuropathologic evidence of AD and concomitant brain infarcts had poorer cognitive function and higher frequency of dementia than those with AD alone.

METHODS

Clinical and neuropsychologic manifestations of dementia were studied in 74 subjects with neuropathologic findings of AD alone and 32 with AD and concomitant cerebral infarcts or lacunar lesions.

RESULTS

The 32 patients with both AD and vascular lesions were significantly older at time of death (median age, 81 years) than the 74 patients with AD alone (76 years; p = 0.02). At the final follow-up visit, the severity of the dementia was greater in AD patients with vascular lesions (median Clinical Dementia Rating [CDR] = 3) than in those with AD alone (CDR = 2; p = 0.03). Patients with AD and vascular lesions performed significantly worse on verbal fluency, Boston Naming, and Mini-Mental State Examination (MMSE) tests. No differences between the groups were observed, however, in the semiquantitative measures of frequency of neuritic plaques or neurofibrillary tangles.

CONCLUSIONS

The clinical-neuropathologic correlations in CERAD patients generally confirm those in prior studies, indicating that the presence of cerebral infarction in patients with AD is associated with greater overall severity of clinical dementia and poorer performance on specific tests of language and cognitive function.

Medication use patterns among demented, cognitively impaired and cognitively intact community-dwelling elderly people

OBJECTIVE

To determine whether medication use patterns in community-dwelling elderly people vary with level of cognitive function-dementia, cognitive impairment (but not dementia) and intact cognition.

DESIGN

Cross-sectional survey.

SETTING

A five-county area of central North Carolina, USA.

PARTICIPANTS

520 members of the Duke Established Populations for Epidemiologic Studies of the Elderly.

MEASUREMENTS

Medication use in the previous 2 weeks was ascertained during a interview in the patient's home and was coded as to prescription and therapeutic class status. Cognitive status, the primary independent variable, was divided into: (i) dementia (n=100); (ii) cognitive impairment but not dementia (n=117); and (iii) cognitively intact (n=303). The dependent variables were any prescription or over-the-counter (OTC) medication use (vs non-use); number of prescription or OTC medications used; and prescription and OTC use combined within major therapeutic classes. Multivariate analyses controlled for socio-demographic characteristics, health status, functional status and access to health care.

RESULTS

The use of any prescription medication was similar in the three groups. The demented were significantly less likely than cognitively impaired people to use any OTC medications (OR=0.65, 95% CI=0.45, 0.93), cardiovascular medications (OR=0.70, 95% CI=0.49, 0.99) and analgesics (OR=0.54, 95% CI=0.39, 0.75). As a combined group, those who were demented and cognitively impaired were less likely than the cognitively intact group to use any OTC medications (OR=0.78, 95% CI 0.65, 0.92). Compared with the cognitively impaired subjects, the demented group took fewer prescription medications (beta coefficient=-0.31, 95% CI=-0.59, -0.03) and similar numbers of OTC medications. Compared with those who were cognitively intact, the combined group of demented and cognitively impaired subjects took fewer OTC medications (beta coefficient=-0.14, 95% CI=-0.23, -0.05) and similar numbers of prescription medications.

CONCLUSION

Increasing level of cognitive dysfunction is associated with decreased use of OTC, cardiovascular and analgesic medications and the use of fewer prescription medications. These results suggest important differences in medication use patterns among community-dwelling elderly people who vary in cognitive status.

Progression of Alzheimer's disease in black and white patients: the CERAD experience, part XVI. Consortium to Establish a Registry for Alzheimer's Disease

We compared the progression of Alzheimer's disease (AD) in CERAD-enrolled black and white patients, as indicated by changes in selected clinical and neuropsychology measures, over a 1-year time interval. Of 225 black and 935 white AD patients who were enrolled, 148 (66%) black and 770 (82%) white patients remained in the study. Of these, 82 black and 532 white patients provided complete in-person information on first annual re-evaluation. Overall, with age, education, initial level of performance on each measure, and stage of disease at entry controlled, race had a very mild effect on change in disease (8 df multivariate analysis of variance [MANOVA], p < 0.047). Black patients showed less decline than white patients, most notably for the CERAD Boston Naming test (p < 0.02) and the third and final trial of the 10-item Word List Learning task (p < 0.003). Although unadjusted data indicate that black and white patients appear to differ notably at entry, our findings indicated that differences in progression of the dementing process are minor, suggesting that course of AD is comparable in these racial groups. Examination over a longer period is difficult because of the high attrition rate of black patients.

The prevalence and 3-year incidence of dementia in older Black and White community residents

OBJECTIVE

To determine the prevalence and 3-year incidence of dementia in Blacks and Whites age 65 and older in a five-county Piedmont area of North Carolina.

DESIGN

Stratified random sample of members of the Duke Established Populations for Epidemiologic Studies of the Elderly (EPESE) (baseline n = 4,136; 55% Black; weighted n = 28,000). Prevalence study members were differentially selected on the basis of score on the Short Portable Mental Status Questionnaire at the second in-person Duke EPESE wave. Incidence study members included all persons with obvious cognitive decline over a 3-year period, and a 10% sample of the remainder.

MEASUREMENTS

Self- and informant report on health history, functional status, and memory. Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Neuropsychology Battery administered to all subjects, and CERAD Clinical Battery to those with impaired memory. Clinical consensus to determine presence and type of dementia.

RESULTS

Prevalence of dementia for persons > or =68 years old was 0.070 (95% confidence interval = 0.021-0.119) for Blacks and 0.072 (0.022-0.122) for Whites. Rates for Black men (0.078, 0.001-0.155) exceeded those for Black women (0.066, 0.003-0.129), but gender rates for Whites were reversed (men: 0.044, 0.000-0.103), (women: 0.087, 0.015-0.160). Neither race nor gender differences were significant. Prevalence of dementia increased through age 84 and tapered off thereafter. Three-year incidence of dementia was 0.058 (0.026-0.090) for Blacks and 0.062 (0.027-0.097) for Whites. Neither race nor gender differences were significant. Incidence increased through age 84, but moderated thereafter for all but Black men. The proportional representation of different types of dementia varied little by race.

CONCLUSION

Prevalence, 3-year incidence, and types of dementia are comparable in Black and White elderly in the Piedmont area of North Carolina.

Consortium to establish a registry for Alzheimer's disease: development, database structure, and selected findings

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) was funded in 1986 by the National Institute on Aging to develop standardized assessments for patients with Alzheimer's disease (AD). Since that time, CERAD has developed and evaluated clinical and neuropsychological test batteries, a neuroimaging protocol, and an assessment of the neuropathological findings of the brains of these patients at autopsy. Approximately 1,200 carefully screened patients with AD and 450 control subjects were evaluated using these instruments at 24 major medical centers around the United States. Annual follow-up observations of these subjects were made for up to eight years. Autopsy examinations of the brain were done in over half of the deceased cases and the clinical diagnosis of AD was confirmed in 85 percent of them. This article outlines the procedures used for identifying the clinical sites, the entry and annual evaluations of patients and control subjects, the collection and analysis of data at a central Methodology and Data Management Center, and evaluation of the CERAD measures. We also present selected data from the 50 or so peer-reviewed papers published to date, with particular emphasis on findings from African-American patients with AD, and related policy implications.

The relationship between extrapyramidal signs and cognitive performance in patients with Alzheimer's disease enrolled in the CERAD Study. Consortium to Establish a Registry for Alzheimer's Disease

The objective of this study was to determine the relationship between the presence of extrapyramidal signs and the severity of cognitive and functional impairment in patients with Alzheimer's disease (AD). Eleven university medical centers in the United States and France participated in the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) study of extrapyramidal signs in AD. Forty-seven patients with probable AD who had extrapyramidal signs were matched by sex, race, education, and age with 132 probable AD patients without extrapyramidal signs. The main outcome measures were the Clinical Dementia Rating, Blessed Dementia Scale, and the CERAD Neuropsychology Battery (verbal fluency, naming, Mini-Mental State Examination, word list learning, word list recall, savings ratio, word list recognition, and constructional praxis). AD patients with extrapyramidal signs performed more poorly than AD patients without parkinsonism on various neuropsychological tests, even after controlling for the Clinical Dementia Rating and reported duration of cognitive impairment. The severity of the extrapyramidal manifestations was related to the degree of cognitive and functional impairment. Muscular rigidity and bradykinesia were the most frequent extrapyramidal signs associated with AD. Patients with AD associated with extrapyramidal signs have greater cognitive and functional impairment than AD patients without clinical evidence of parkinsonism.

Differential relationships of risk factors to alternative measures of disability

The purpose of this article was to determine whether risk factors for four dimensions of disability differ and whether it is legitimate to use aggregated disability measures in risk factor analyses. Using data from the baseline Duke Established Populations for Epidemiologic Studies of the Elderly survey (n = 4,162), the authors examined four measures of disability--basic activities of daily living (ADLs), household ADLs, advanced ADLs, and mobility--and an aggregated measure consisting of these four measures summed. Sociodemographic risk factors were examined using stagewise multivariate regression analysis for the five measures of disability. Weighted least squares with an arbitrary distribution function estimator were used to determine differences in each risk factor's performance across the unaggregated measures. Risk factors varied in strength, presence, and direction of impact across the four dimensions of disability; as a result, analyses using an aggregated measure were misleading.

Memory complaint as a predictor of cognitive decline: a comparison of African American and White elders

Of a representative, racially mixed community sample of older adults in North Carolina, 59% of Whites and 49% of African Americans reported worsening memory. The complaint about memory was positively correlated with age, depressive symptomatology, and physical function but not with level of cognitive function as measured by the Short Portable Mental Status Questionnaire (SPMSQ) at baseline. In a controlled analysis of longitudinal data, initial SPMSQ score, age, African American race, lower education, depressive symptomatology, and physical deficits at baseline, but not memory complaint, predicted a decline in cognitive function as measured by the SPMSQ 3 years later. Whereas African Americans were less likely to complain of deterioration in memory, actual decline as measured by the SPMSQ was greater for African Americans than for Whites.

Performance of elderly White and African American community residents on the abbreviated CERAD Boston Naming Test

Differences in the responses of an elderly biracial group of cognitively normal subjects to a 15-item short version of the Boston Naming Test developed for the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) were examined. The subjects consisted of 103 Whites and 136 African Americans who were 70 years of age and older and living in a five-county urban and rural area of North Carolina. They were drawn from the Duke University site of the Established Populations for Epidemiologic Studies of the Elderly (EPESE). All were cognitively normal. With gender, years of education, and age controlled, White subjects performed significantly better than did African American subjects. The items in this test were selected to represent words with a high, medium, and low frequency of occurrence in English. They did not, however, show the expected gradation for either racial group. Medium and low frequency items were of comparable difficulty for the two races. Hierarchical ordering of difficulty would be improved with minor rearrangement of items.

Black-white differences in risk of becoming disabled and recovering from disability in old age: a longitudinal analysis of two EPESE populations

This study compared the odds of becoming disabled and recovering from disability among blacks and whites aged 65 years and over in two sites of the Established Populations for Epidemiologic Studies of the Elderly (EPESE) project. The authors examined the influence of mortality differences, socioeconomic status, and health-related factors on racial differences in risk of disability and recovery. A Markov model was employed using nine waves of data from the New Haven, Connecticut, site (529 blacks, 2,219 whites) and seven waves of the North Carolina (Piedmont) site (2,260 blacks, 1,876 whites), collected between 1982 and 1992. Blacks below age 75 years had an increased risk of developing disability relative to whites in New Haven (odds ratio (OR) at age 65 years = 3.33, 95% confidence interval (CI) 2.13-5.22) as well as in North Carolina (OR at age 65 years = 1.58, 95% CI 1.25-1.99). This excess risk diminished with increasing age, and crossed over in New Haven (OR at age 85 years = 0.45, 95% CI 0.22-0.95), but not in North Carolina (OR at age 85 years = 1.22, 95% CI 0.98-1.51). Adjustment for socioeconomic and health-related factors only partially reduced the excess disability risk among blacks below age 75 years in New Haven, but eliminated the difference in disability risk between blacks and whites in North Carolina. Blacks below age 75 years also had higher mortality risks at both sites. There were no consistent racial differences in recovery from disability.

Relation of prescription nonsteroidal antiinflammatory drug use to cognitive function among community-dwelling elderly

PURPOSE

To evaluate the relationship of nonsteroidal antiinflammatory drug (NSAID) use to level of cognitive function in community-dwelling elderly persons.

METHODS

The prospective cohort study included 2765 nonproxy subjects from the Duke University Established Populations for Epidemiologic Studies of the Elderly who were cognitively intact at baseline (1986-1987) and alive at follow-up three year later. Cognitive function was assessed by the Short Portable Mental Status Questionnaire (i.e., intact vs. impaired and change in score) and by the individual domains of the Orientation-Memory-Concentration Test (i.e., number of errors). NSAID use, determined from in-home interviews, was coded for chronicity, dose, frequency of use, and prescription status.

RESULTS

After controlling for demographic factors as well as health status and behavior, continuous, regularly-scheduled, prescription use of NSAID was associated with preservation of one aspect of cognitive functioning: concentration (beta coefficient, 0.29; 95% confidence interval [CI] -0.54 to -0.04, indicating fewer errors). However, no consistent dose-response relationship was found. Current and prior NSAID use was unrelated to level of cognitive functioning across all five measures; among current users, those taking moderate or high doses (beta coefficient, 0.41; 95% CI, 0.08 to 0.74) made more errors on the memory test compared with those taking low doses (beta coefficient 0.03; 95% CI, -.85 to 0.91).

CONCLUSIONS

These results suggest no substantial or consistent protective effect of prescription NSAID use on cognitive function in community-dwelling elderly. However, recent use at higher doses may be associated with memory deterioration in this population.

Estimating the validity of the clinical Dementia Rating Scale: the CERAD experience. Consortium to Establish a Registry for Alzheimer's Disease

The Clinical Dementia Rating (CDR) scale is broadly accepted by clinicians as a staging measure for Alzheimer's disease (AD). Extensive assessment of its validity is, however, lacking. We examined the concurrent and predictive validity of both summary CDR scores (global CDR, Sum of Boxes [sum of scores on the individual components]) and scores on two (Memory and Orientation) of the CDR's six components (the other four components are judgement and problem-solving, community affairs, home and hobbies, personal care) using cross-sectional, longitudinal and survival information on 434 community-resident probable AD patients. Cross-sectionally the Orientation box score correlated substantially with an independent neuropsychology measure of orientation, but the Memory box score correlated more poorly with an independent measure of memory than with any other neuropsychology measure. The relationship of the global CDR score and the Sum of Boxes score to scores on neuropsychology measures was comparable to that of the Orientation and Memory box scores. Longitudinally, Memory box score a year later was predicted equally well by the other box scores (personal care excepted). The individual components were comparable to both summary CDR scores in predicting time to death. The CDR has content and criterion validity. However, since intentionally all components measure aspects of cognitive functioning, they are closely related. Nevertheless, sufficient distinctions remain that assessment in each area is still warranted.

Factors associated with suboptimal analgesic use in community-dwelling elderly

OBJECTIVE

To examine patterns and factors associated with overall and suboptimal analgesic use among community-dwelling elderly.

DESIGN

Cross-sectional survey.

SETTING

Five-county urban and rural region in Piedmont, NC.

PARTICIPANTS

A stratified random sample from the Duke Established Populations for Epidemiologic Studies of the Elderly of 3973 participants aged 65 years or older.

MAIN OUTCOME MEASURES

Use of any analgesic medication, suboptimal analgesic use (taking 2 or more analgesics from the same class, using 3 or more analgesics concurrently, or use of an analgesic that has a major interaction with another drug).

RESULTS

Analgesics were used by 60.4% of the participants. Use was more likely for those who had physical functional impairment, a history of cardiovascular disease, one or more health visits in the previous year, or were female. Use was less likely for older participants and for African-Americans with adequate financial status. Suboptimal use occurred in 9.2% of analgesic users. Therapeutic duplication was more likely in those who were depressed, needed help with basic activities of daily living, or used alcohol, and was less likely in those with adequate financial status. Multiple analgesic use was more likely in those who were depressed, had impaired physical functional status, had one or more health visits in the previous year, were African-American (of either sex), or were white women. Only two persons had a potential major analgesic-drug interaction.

CONCLUSIONS

Suboptimal analgesic use is common in community-dwelling elderly, and its risk in consistently increased in those who are depressed or have impaired physical functional status.

Predictors of nutritional supplement use by the elderly

We conducted a population survey to describe patterns and determine predictors of the use of nutritional supplements and single-ingredient vitamins and minerals among elderly living in five adjacent urban and rural counties in the Piedmont area of North Carolina. The stratified random sample consisted of 3939 black and white participants age 65 or older from the Duke Established Populations for Epidemiologic Studies of the Elderly. The use of nutritional supplements within the previous 2 weeks was determined during an in-home interview. Multivariate analyses, using weighted data adjusted for sampling design, were conducted to assess the association between nutritional supplement use and predisposing, need, and enabling factors. Nutritional supplement use was reported by 26.2% of participants and was more likely for those who were white women, were high school educated, were underweight, took prescription drugs, had five or more health visits in the previous year, and had supplemental health insurance. It was less likely for those with poor self-rated health. The majority (71.5%) of nutritional supplement users took at least one single-ingredient supplement. Use of such products was more likely in those who were white, born and raised in an urban area, and high school educated, and was less likely in those with impaired functional status. Nutritional supplement use is prevalent in community-dwelling elderly and is more commonly associated with demographic factors and access to health care than with need factors.

Factors predicting change in prescription and nonprescription drug use in a community-residing black and white elderly population

The current study identifies characteristics that predict change in use of prescription and nonprescription drugs over a period of 3 years. A modified health care services use model was applied to information obtained from a probability-based sample of black (n = 1778) and white (n = 1446) community-resident elderly, interviewed in 1986-1987 and 1989-1990. Analysis was by means of logistic and ordinary least-squares regression, with sample weights and design effects taken into account. The number of users and average number of prescription drugs used increased over the 3 years, and was best predicted by extent of prior drug use, older age, white race, poorer health, and number of health care visits. Conversely, nonprescription drug use declined significantly, and was best predicted by prior use, white race, and female gender. The reduced use of prescription drugs by blacks as compared to whites is of concern, suggesting that attention is needed to assure equitable access to prescription drugs.

Is medication use by community-dwelling elderly people influenced by cognitive function?

To determine whether medication use differs by cognitive status among community dwelling elderly, a survey was made of a stratified random sample of 4110 black and white participants, aged 65 or older from the Duke Established Populations for Epidemiologic Studies of the Elderly in five adjacent urban and rural counties in the Piedmont area of North Carolina. Main outcome measures were usage of prescription medications, non-prescription medications, and medicines within therapeutic classes in the previous 2 weeks as determined during an in-home interview; and total number of prescription and non-prescription medicines used in the previous 2 weeks. Multivariate analyses, using weighted data adjusted for sampling design, were conducted to assess the association between drug use patterns and cognitive status, as assessed by the Short Portable Mental Status Questionnaire, while adjusting for demographic, health status, and access to health care factors. Participants with cognitive impairment (13.7% of sample) were less likely to use any prescription medications (Adjusted OR = 0.66, 95% CI = 0.48-0.90) or any non-prescription medications (Adjusted OR = 0. 71, 95% CI = 0.56-0.89) than cognitively intact subjects. Both groups took a similar number of prescription and non-prescription medications. Those who were cognitively impaired were less likely to take analgesics (Adjusted OR = 0.66, 95% CI = 0.52-0.83), but were more likely to take central nervous drugs (Adjusted OR = 1.55, 95% CI 1.18-2.04) than those who were cognitively intact. We conclude that drug use patterns by community-dwelling elderly people differ with cognitive status. Future research needs to examine medication use by specific causes of cognitive impairment.

Analysis of change in self-reported physical function among older persons in four population studies

Change in self-reported physical function was examined using baseline and 5 years of follow-up data between 1982 and 1991 from the four Established Populations for Epidemiologic Studies of the Elderly studies. In East Boston, Massachusetts (n = 3,809), Iowa and Washington Counties, Iowa (n = 3,673), New Haven, Connecticut (n = 2,812), and North Carolina (n = 4,163), noninstitutionalized persons aged 65 years and older were asked a series of questions to assess their physical function: a modified Katz Activities of Daily Living (ADL) scale, three items from the Rosow-Breslau Functional Health Scale, and questions on physical performance, adapted from Nagi, as well as information on demographic, social, and health characteristics. Longitudinal statistical analyses (random effects and Markov transition models) were used to evaluate improvement, stability, and deterioration in functional ability at both an individual and a population level over multiple years of data. The average decline in physical function associated with age was found to be greater than previous cross-sectional studies have suggested, and the rate of decline increased with increasing age. Considerable individual variation was evident. Although many people experienced declines, a smaller but substantial portion experienced recovery. Women reported a greater rate of decline in physical function and were less likely to recover from disability.

The consortium to establish a registry for Alzheimer's Disease (CERAD). Part XIII. Obtaining autopsy in Alzheimer's disease

Although autopsy rates in the United States have been decreasing steadily, the necessity for brain autopsy to confirm Alzheimer's disease (AD) remains. Of 308 consecutively deceased AD patients at 24 CERAD (Consortium to Establish a Registry for Alzheimer's Disease) sites, 167 (54%) were autopsied; 141 (46%) were not. The autopsied and nonautopsied groups were comparable in gender (men, 57.5% versus 49.7%), marital status (married, 69.3% versus 67.1%), age at entry (73 versus 74 years), age at death (76 versus 77 years), and stage of disease at entry (mild, 46% versus 43%). However, the autopsied patients were significantly more likely to be white (94.5% versus 82.1%), to be better educated (13.1 versus 11.3 years), to have been in the study longer (mean, 3.3 versus 2.6 years), and to have had longer total duration of AD (8.1 versus 6.7 years). Of the 24 CERAD sites, 13 stressed the importance of autopsy by dedicating a staff member to seek autopsy and by providing free autopsy and transportation; 11 did not. Logistic regression analysis showed that white race (odds ratio [OR] = 2.74; 95% confidence interval [CI] = 1.10-6.83), increased education (OR = 1.12; 95% CI = 1.04-1.21), and emphasis on autopsy (OR = 4.69; 95% CI = 2.67-8.25) were the only significant factors. Although race and education were important, autopsy was more likely to be obtained when sites dedicated resources to this endeavor.

Black-white and urban-rural differences in stability of household composition among elderly persons

The dynamic nature of household composition in a population of elderly persons, with particular focus on Black-White and urban-rural differences, is described in this study. The Duke EPESE is a stratified, random household sample (N = 4,162) of elderly persons in a five-county mixed urban-rural area of North Carolina with respondents contacted annually to report on health and social factors. Between 1986 and 1990, 35 percent of the households underwent some change in composition, with 14 percent contracting and/or expanding more than once. Where elders lived alone and where married elders lived with the spouse and/or others, Black elders were significantly more likely to experience a net expansion of their household than were White elders of the same age, gender, socioeconomic, and functional status. Elderly residents of rural areas who lived alone were slightly more likely to add one or more persons to their households than were comparable elderly urban residents. No additional risk of household instability was noted in sociodemographic or health-related subgroups by race or residence. Future analyses should examine the outcomes of instability.

Functional disability among elderly blacks and whites in two diverse areas: the New Haven and North Carolina EPESE. Established Populations for the Epidemiologic Studies of the Elderly

This study examines the prevalence of functional disability (limitation in at least one basic activity of daily living) among elderly Black and White community residents in the New Haven (n = 2812) and North Carolina (n = 4162) sites of the Established Populations for Epidemiologic Studies of the Elderly (EPESE). In New Haven, elderly Blacks, particularly women below age 75, had a higher prevalence of disability compared with Whites, which was partially attributable to a higher prevalence of chronic conditions. In North Carolina, Blacks had only a slightly higher risk of being disabled than Whites, and this was fully accounted for by differences in socioeconomic status. Black-White differences in the prevalence of functional disability reveal geographic variation.

The comprehensive assessment of community dwelling elderly: why functional status is not enough

The present study attempts to determine empirically the relationship of measures of functional status to other domains common to geriatric assessment, and to ascertain whether functional status can substitute for other domains of clinical assessment. A comprehensive research survey was administered in the home to a randomly selected population of 4163 community residents aged 65 and over in the Duke EPESE, one of the four sites of the National Institute on Aging-funded Established Populations for Epidemiologic Studies of the Elderly. Sample members were predominantly black (55%), female (65%), between 65 and 74 years of age (61%), and lived in five contiguous counties within the state of North Carolina. Measurements included three measures of functional status ranging from basic activities of daily living (ADL) to strenuous mobility items, and summary measures of cognition, depression, and overall physical health. The three functional status measures were inter-correlated. However, with the exception of cognitive status and performance of instrumental ADL, the functional status measures failed to show a clinically significant relationship with the domains of cognition, depression, or overall physical health status. Furthermore, even among those sample members impaired in all three domains, 8% could still perform strenuous activities, and over 50% could still perform the basic activities of daily living. The data show that functional status measures are not necessarily indicative of an elder's mental or physical health. Each domain of assessment contributes unique data, and no one area can fully substitute for another.

Discrimination between stages of Alzheimer's disease with subsets of Mini-Mental State Examination items. An analysis of Consortium to Establish a Registry for Alzheimer's Disease data

OBJECTIVE

To identify minimal sets of Mini-Mental State Examination (MMSE) items that can distinguish normal control subjects from patients with mild Alzheimer's disease (AD), patients with mild from those with moderate AD, and those with moderate from those with severe AD.

DESIGN

Two randomly selected equivalent half samples. Results of logistic regression analysis from data from the first half of the sample were confirmed by receiver operating characteristic curves on the second half.

SETTING

Memory disorders clinics at major medical centers in the United States affiliated with the Consortium to establish a Registry for Alzheimer's Disease (CERAD).

PARTICIPANTS

White, normal control subjects (n = 412) and patients with AD (n = 621) who met CERAD criteria; nonwhite subjects (n = 165) and persons with missing data (n = 27) were excluded.

MAIN OUTCOME MEASURES

Three four-item sets of MMSE items that discriminate, respectively, (1) normal controls from patients with mild AD, (2) patients with mild from those with moderate AD, and (3) patients with moderate from those with severe AD.

RESULTS

The MMSE items discriminating normal controls from patients with mild AD were day, date, recall of apple, and recall of penny; those discriminating patients with mild from those with moderate AD were month, city, spelling world backward, and county, and those discriminating patients with moderate from those with severe AD were floor of building, repeating the word table, naming watch, and folding paper in half. Performance on the first two four-item sets was comparable with that of the full MMSE; the third set distinguished patients with moderate from those with severe AD better than chance.

CONCLUSIONS

A minimum set of MMSE items can effectively discriminate normal controls from patients with mild AD and between successive levels of severity of AD. Data apply only to white patients with AD. Performance in minorities, more heterogeneous groups, or normal subjects with questionable cognitive status has not been assessed.

Comparison of spouse and nonkin controls: the experience of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD)

Normal spouses may be an excellent source of control subjects in research on noninstitutionalized Alzheimer's disease (AD) cases. To determine to what extent spouses might differ from nonkin controls, we compared information on 145 spouses of AD patients with 158 nonkin community volunteers enrolled by 23 centers of the Consortium to Establish a Registry for Alzheimer's Disease. Chi square and 1-way ANOVA analyses indicate that neither at entry nor over the next two years did the two groups of controls differ significantly on demographic characteristics, health status, or performance on neuropsychological measures. However, hierarchical logistic regression showed that, after controlling for demographic characteristics and physical status, dropout was nearly twice as high among spouse controls. Dropout was related to nonreturn of the AD case. Thus, as controls, spouses are viable as long as the cases to whom they are married remain in the study.

Nutrition and function: is there a relationship between body mass index and the functional capabilities of community-dwelling elderly?

OBJECTIVE

To determine if there is a relationship between body mass index and the ability to perform the usual activities of living in a sample of community-dwelling elderly.

DESIGN

Secondary data analysis of The National Health and Nutrition Examination Survey-I Epidemiologic Follow-up Study (1982-1984). Follow-up home interview of a population-based sample originally interviewed between 1971 and 1975 in the National Health and Nutrition Examination Survey-I (NHANES-I).

PARTICIPANTS

Survivors of the original NHANES-I cohort who were 65 years of age or older and who were living at home at the time of the second interview (n = 3061). Excluded were those who could not be found, refused participation, or were institutionalized (n = 220), and those without complete height and weight data (n = 194).

MAIN OUTCOME MEASURE

Functional status as measured by a 26-item battery.

RESULTS

Bivariate analysis revealed a greater risk for functional impairment for subjects with a low body mass index or a high body mass index. The greater the extreme of body mass index (either higher or lower), the greater the risk for functional impairment. Logistic regression analysis indicated that both high and low body mass index continued to be significantly related to functional status when 22 other potential confounders were included in the model.

CONCLUSION

The body mass index is related to the functional capabilities of community-dwelling elderly. The inclusion of this simple measurement in the comprehensive assessment of community-dwelling elderly is supported.

Prescription and nonprescription drug use among black and white community-residing elderly

OBJECTIVES

To examine and compare concomitants of prescription and nonprescription drug use of Black and White community-dwelling elderly.

METHODS

Information on prescription and nonprescription drug use, demographic and health characteristics, and use of health services was obtained from a probability-based sample of Black (n = 2152) and White (n = 1821) community-resident elderly in the Piedmont area of North Carolina. Descriptive statistics were calculated. Linear regression, in which sample weights and design effects were taken into account, was used for the final models.

RESULTS

For prescription drug use, 37% and 32% of the variance was explained for Whites and Blacks, respectively (6% and 5% for nonprescription drugs). Health status and use of medical services were the strongest predictors of prescription drug use for both races (with Medigap insurance also important for Whites and Medicaid important for Blacks). Demographic characteristics and self-assessed health were significant factors in the use of nonprescription drugs. Race independently predicted use of both types of drugs but explained only a small proportion of the variance.

CONCLUSIONS

Health status and use of health services are importantly related to prescription drug use. Non-prescription drug use is difficult to explain.