Psychosomatics 44:461-470, December 2003
© 2003 The Academy of Psychosomatic Medicine
Relationship of Self-Perceptions of Memory and Worry to Objective Measures of Memory and Cognition in the General Population
Laura Jean Podewils, Ph.D.,
Robert N. McLay, Ph.D., M.D.,
George W. Rebok, Ph.D., and
Constantine G. Lyketsos, M.D., M.H.S.
Received June 6, 2002; revision received Jan. 10, 2003; accepted Feb. 6, 2003. From the Departments of Epidemiology and Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore; the Department of Psychiatry, Naval Medical Center San Diego; and the Division of Geriatric Psychiatry and Neuropsychiatry, Department of Psychiatry, Johns Hopkins University, Baltimore. Address reprint requests to Dr. Lyketsos, Division of Geriatric Psychiatry and Neuropsychiatry, Johns Hopkins Medical Institutions, 600 N. Wolfe St., Osler 320, Baltimore, MD 21287; kostas{at}jhmi.edu (e-mail).
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ABSTRACT
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This investigation compared how perceived memory ability or level of worry about memory related to performance on objective tests of memory and cognition. Data from 1,488 participants from the Baltimore cohort of the Epidemiologic Catchment Area study were analyzed. Significant associations were found between self-ratings of memory and each of four objective measures of cognitive functioning. Memory worry was associated with worse delayed recall but not with worse word recognition, lower current Mini-Mental State Examination (MMSE) score, or greater change in MMSE score over time. Individuals experiencing changes in cognitive function appear to have some awareness of their condition, and a simple probe of a person's perception of memory in the context of a general medical evaluation may help identify those who need further assessment.
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INTRODUCTION
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Problems with memory and episodes of "forgetfulness" are often regarded as a normal part of the aging process. Several studies have noted the frequency of subjective memory complaints among older persons. One-third of a group of 349 noninstitutionalized adults age 75 years and older in Europe were reported to have complaints about memory.1 This estimate is similar to the findings of other researchers, who reported such complaints in 31% of a group of non-cognitively-impaired elderly persons.2 In another study, Tobiansky et al.3 found subjective memory impairment among 25% of a group of elderly persons living in London. Others have reported a higher occurrence of memory complaints in community-dwelling older persons and have also reported that the frequency of complaints rises linearly after the age of 65 years (43% for persons age 65–74 years, 51% for persons age 75–84 years, and 88% for those age 85 years and older).4
In contrast, the subject of memory is rarely addressed before the person reaches the fifth or sixth decade of life, even though memory changes are believed to be part of a gradual lifelong process.5 Indeed only a few epidemiologic studies have assessed the frequency of memory complaints among younger persons.4,6,7 In a population study of 2,000 people in the Netherlands, nearly 40% of those age 24–86 years considered themselves forgetful.7 Bolla et al.6 found that only a small proportion (19%) of subjects age 39–89 years had no memory complaints. In contrast, in earlier work from the Baltimore Epidemiologic Catchment Area (ECA) study, only 22% of community-sampled adults (>18 years old) indicated that they had memory trouble.4
It is unclear whether subjective complaints of memory trouble in a population setting are indicative of an underlying pathology or are simply reflective of intra-individual variability in memory function. Cognitive impairment is associated with an increased risk for a number of diseases,8 worse quality of life,9 impaired physical functioning,8,10 institutionalization,11 and earlier death.12,13 In addition, loss of memory is noted by the popular press as one of the greatest fears among persons age 65 years and older, amplified perhaps by the increased media attention to Alzheimer's disease and related disorders over the past decade. Thus, while memory complaints across all ages appear to occur, the relationship between self-reported complaints and objectively measured memory or cognitive ability has been inconclusive and has not been adequately assessed in population studies.14,15
Many of the studies that have failed to demonstrate a relationship between subjective memory complaints and memory performance have been clinic-based or cross-sectional in design and have not included subjects with cognitive impairment or comparison subjects without memory complaints.2,16 Studies in clinical populations would be subject to a referral bias in that subjective memory complaints may lead to a clinical evaluation and an overrepresentation of subjects with such complaints in the study group. These patients are likely to present to the clinic setting because their memory difficulty is impeding their ability to perform daily activities and/or they are there at the insistence of friends and family members who have observed a marked impairment or change from previous capacity. Relatively few studies have examined the relationship between memory complaints and memory performance in nondemented, nondepressed individuals living in the community, but proportionately, these individuals represent the largest group at risk for memory impairment.16
The few population-based studies that have specifically addressed relationships between subjective and objective memory have not yielded firm conclusions about their relationship across the adult age span. In three studies, significant relationships between self-reported memory complaints and objective tests of memory performance were reported in adults age 65 years and older.2,16,17 However, these relationships held true primarily for persons who showed clear evidence of cognitive impairment. Similar findings were reported by Bassett and Folstein4 in their study of 810 adults age 18–92 years from the ECA study. The cognitive functions that appear to be most strongly associated with complaint status included recall, factual memory, orientation to time and place, and category fluency.16
Besides age, other factors such as sex, educational level, and depressive symptoms have been found to correlate with self-reported memory problems and performance on objective memory tests. In line with previous findings, women have been reported to perceive more problems with their memory function than men,17 and less well-educated persons have been found to report more memory decline as well as lower memory performance.4
The presence of depressive symptoms or disorder is also associated with significantly higher levels of memory complaint,4,18–20 but not always with lower levels of memory performance. In fact, in some studies,21–23 subjects with complaints actually performed better than those without complaints on objective memory tests.
In the current study we examined a population-based cohort from east Baltimore followed from 1981 to 1996 as part of the ECA study. In the ECA's third wave (1993–1996), participants self-reported on how good they thought their memory was and on whether they were worried about their memory. In addition, a 20-word recall task and a word recognition task were administered. Study participants also were administered the Mini-Mental State Examination (MMSE) in all three waves (1981, 1982, and 1993–1996).
The first aim of the current investigation was to describe the frequency and sociodemographic associations of self-perceived memory function and the frequency and prediction of memory worry in a population-based sample of adults. The second aim was to compare self-reports of memory function and worry about memory with objective measures of memory and cognitive functioning and with cognitive change over the study follow-up.
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METHOD
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Subjects
Data were collected from participants as part of the ECA follow-up study, which has been described in detail elsewhere.24,25 The ECA was conducted in three waves, with wave 1 in 1981, wave 2 in 1982, and wave 3 between 1993 and 1996. The initial wave 1 target population consisted of residents of eastern Baltimore, a population of 175,211 adults in 1981. Of these, 4,238 were initially designated by probability sampling methods for an interview, with 3,481 interviews successfully completed (wave 1). In the second wave 2,695 (77.4%) of the initial respondents completed the survey. All participants provided informed consent before the interviews. The study was reviewed and approved by the Committee on Human Research of the Johns Hopkins School of Hygiene and Public Health.
All of the original participants were targeted for tracing in wave 3 (1993–1996). The wave 3 household interview, conducted with 1,920 participants, included MMSE testing, a recall and a recognition task, and questions about several demographic descriptors. A total of 1,488 participants completed the MMSE in all three waves, and 1,718 answered two self-reported memory questions. Only persons with complete data on all measures were considered in the present analysis (N=1,488).
Subjective Assessment of Memory
As stated earlier, the memory self-report questions were administered to all participants by a trained lay interviewer. The first question asked subjects how their memory was, compared to that of other people of their own age. Respondents answered on a 5-item Likert scale on which 1 indicated very poor; 2, fair; 3, good; 4, very good; and 5, excellent. The second question, "How often do you worry about forgetting things?" was scaled as follows: 1, worry often; 2, worry occasionally; and 3, no worry.
Objective Assessment of Memory and Cognitive Functioning
Delayed recall
Participants completed a recall and a recognition task from the Iowa Established Populations for Epidemiologic Studies of the Elderly project26 at wave 3. They were asked to listen to a list of 20 common words, such as "army," "coffee," "forest," and "winter," which were read one word at a time at a rate of approximately one word every 2 seconds. They were then required to recall aloud the words on the list in any order. After an interval of about 20 minutes, a delayed test of recall of the same word list was performed and the total number of correct words recalled was recorded. This estimate of delayed recall was one of the dependent variables in the study.
Discrimination index for recognition
After the delayed recall task, a list of 40 words, including the 20 words originally listed, was presented on a sheet of paper, and respondents were asked to identify the original 20 words by placing a check mark next to each word. A discrimination index was calculated by subtracting the number of words incorrectly identified in this task from those correctly recognized. The discrimination index was a second dependent variable in study analyses.
Cognitive Functioning and Change
The MMSE has been used widely in the clinical setting and offers a valid and reliable index of global cognitive function.27 The MMSE assesses several aspects of cognition, including orientation, attention, calculation, recall, language, and visual construction. It correlates well with a number of other cognitive tests (e.g., Trails B, Wechsler Memory Scale, digit span, story recall, word list recall, Wechsler Adult Intelligence Scale, Blessed Information Memory Concentration Test) and has a high level of sensitivity for moderate to severe impairment.28 Administration and scoring in the present study adhered to previous recommendations for the general adult population.29
We previously used the MMSE to demonstrate longitudinal cognitive decline across all age groups as well as the effect of education, race, and cognitive level on that decline.25 In the current study, we used the total MMSE score at wave 3 as an indication of current cognitive functioning and change in MMSE score between wave 2 and wave 3 as a measure of cognitive change in the past 11.5 years (median interval).
Sociodemographic and Medical Factors
Information was gathered on factors believed to influence subjective or objective memory performance or cognitive functioning. Demographic data on age, gender, race, and highest level of education achieved were collected for all participants at wave 1. Education level and age were updated at wave 3. The average age at wave 3 was 53.5 years (SD=16.3, range 31–97), and the mean number of years of education was 11.6 (SD=2.6, range 0–17).
Statistical Analysis
Chi-square and Fisher's exact tests were used to test for differences in responses to the two memory self-report questions across demographic categories. Multivariate linear regression models were used to determine the relationship of self-reported perception of memory and degree of worry about memory to objective memory and cognitive scores. A separate model was constructed for each of the dependent variables (scores on the MMSE at wave 3, delayed recall score, discrimination index, and change in MMSE score). We tested each of the two memory self-report questions separately for their association with each dependent variable. In exploratory analyses in which dummy variables represented each of the primary independent variables, we found that the assumption of linearity was not significantly violated, so these variables were treated as ordinal in all analyses. Sociodemographic variables were entered individually into the models as covariates and remained if they were deemed statistically significant by the likelihood ratio comparison at a level of p<0.05, or were otherwise considered on the basis of previous evidence suggesting importance for subjective and objective measures. Each model was constructed by using data from all participants who had answered all the questions represented in the equation.
All analyses were performed using the Stata 6.0 statistical package (Stata Corporation, Galveston, Tex.).
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RESULTS
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Table 1 presents the distribution of self-ratings of memory ability and the frequency of memory complaints in the sample, by demographic characteristics. With the exception of the oldest age group, the majority (>50%) of persons of all age, educational, gender, and race categories rated themselves as having "very good" memory, with very few (<5%) rating themselves as having "fair" or "poor" memory. The "fair" and "poor" categories were collapsed for all further analyses because of limitations associated with having small numbers within cells. Significant differences in the distribution of self-perceived memory ratings were noted by age category, but post hoc analyses revealed that these differences were primarily due to the oldest age group's rating their memory as "very good" less frequently (p<0.05). No other differences between age groups were significant, and no gender differences were found. Persons with educational attainment of less than 12 years and black persons rated their memory as slightly poorer than those with at least a high school education and nonblacks, but the differences were not significant.
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TABLE 1. Subjective Ratings of Memory Ability and Frequency of Worry About Memory in a General Population Sample (N=1,488), by Sociodemographic Characteristicsa
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Similar conclusions were reached for the proportion of respondents reporting worry about memory. More than one-half of the persons in each age category reported no worry. Compared to middle-aged adults (age 40–50 years), a significantly smaller proportion of persons age 70–80 years worried about their memory. All educational groups and both racial groups had similar patterns of concern about memory function; however, more female than male respondents reported worry. It is noteworthy that female respondents rated their memory performance as similar to that of male respondents. Thus, it appears that the question about memory performance and the question about memory worry assessed two different constructs.
Table 2 shows mean scores on the objective tests of memory and cognitive function for respondents grouped by their subjective ratings of memory and worry about memory. Table 3 shows coefficients and 95% confidence limits for the relationships of self-perception of memory and worry about memory with the change in MMSE score, current MMSE score, discrimination index, and delayed recall score as modeled by univariate and multivariate linear regression models. All multivariate models included adjustments for current age, educational level, gender, and race. A positive association was initially noted between subjective memory assessment and all four of the dependent outcomes, with better perceptions of memory (e.g., "excellent") related to better scores and less cognitive decline. However, after adjustment for confounding variables, the relationship of perceived memory capacity and change in cognitive performance over the past 11.5 years was undetectable. Individuals who reported more worry often had concurrently poorer scores on the delayed recall test, but no association was noted between the levels of worry and scores on the discrimination index, global cognitive function measure (MMSE score), or change in cognition over time (change in MMSE score). Thus, occasional worry was relatively common, and the relationship between occasional worry and objective memory scores was not significantly different from the relationship between no worry and objective memory scores.
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TABLE 2. Scores on Objective Measures of Memory and Cognition in a General Population Sample (N=1,488) Grouped by Subjective Ratings of Memory Ability and Frequency of Worry About Memorya
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TABLE 3. Univariate and Adjusted Regression Analyses of the Relationship of Objective Measures of Memory and Cognition Ability With Subjective Ratings of Memory Ability and Frequency of Worry About Memory in a General Population Sample (N=1,488)a
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All final models contained age as a continuous variable and education (<12 years, high school education or equivalent, and  13 years), race (black, nonblack), and gender as categorical variables. Only eight participants had a clinical diagnosis of depression at wave 3 testing; consideration of this variable in multivariate models did not alter the coefficients or our inferences significantly.
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DISCUSSION
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In this large-scale population study comparing self-perception of memory to objective performance on tests of delayed recall, recognition memory, and global cognitive function, 96.7% of participants rated their memory as "good" or better in reference to other persons their age. Persons age 80 years and older perceived their memory as poorer than young (age 30–40 years) and young-old (age 60–70 years) respondents. No other differences were identified across 10-year age categories, and female respondents rated their memory comparably to male respondents. Although there was a slight tendency for persons with fewer years of education and black persons to rate their memory as poorer than others, these trends were nonsignificant in the present sample.
In contrast, more than one-third (36%) of the sample worried about their memory. Eleven percent of those who were worried reported worrying "often." Middle-aged adults (age 40–50 years) and women worried more than did older people (age 70–80 years) and men. Thus, worry about memory, at least occasionally, is quite widespread even in younger persons. It is interesting to note that self-perception correlated weakly with objective performance in all age groups; however, worry did not. We conclude that even though worry is common, most of the time it is not associated with a measurable deficit in major cognitive function. In comparison, self-perception of memory function may be a better indicator of objective performance.
Our research contributes to the small number of previous population studies that have compared subjective and objective ratings of memory by sociodemographic variables across a wide age span. In addition, the median 11.5-year follow-up period in our study is, to our knowledge, more extensive than that of any previous study evaluating cognitive change. Previous longitudinal studies addressing the issue of subjective and objective rating of memory among healthy (not cognitively impaired) subjects have been limited in their ability to detect cognitive change because of their short follow-up periods, which have ranged from 1 to 3.5 years in duration. The present findings should reassure younger people in the baby-boom generation that memory worry is frequent but generally unfounded on the basis of objective testing. Worry about memory is not indicative of a significant decline or dementia but likely reflects a shift in attention or interest.
Most studies have failed to find a significant association of cognitive performance to self-reports of memory or memory complaints. Due to the infrequency of depression in our population-based sample, we could not factor in the influence of depression as a correlate to objective memory performance, which has been identified as a better predictor of memory than subjective complaints in several of the studies reviewed.2,6,19 Recognizing that depression can confound both subjective and objective performance, we evaluated the role of clinical depression at wave 3 in the relationships identified. Because the number of persons in the sample was small, the analyses completed with this adjustment did not alter our conclusions significantly.
It is not surprising that younger adults and older adults into the seventh decade of life had similar perceptions of memory ability in the present sample, given that they were asked to rate their own memory in contextual reference to their peers. Although it is commonly regarded that older adults perceive their memory as becoming poorer as they age, they may also consider their overall peer group as declining, so their relative status remains fairly stable.
Our findings are consistent with a recent cross-sectional study involving community-dwelling, nondepressed adults that reported a significant association between memory complaints and poorer performance on objective tests.16 Persons who had a greater proportion of memory complaints and problems scored in the lower range of the MMSE,16 a result that is similar to the association of memory self-rating and memory worry with current MMSE scores among the female respondents in our study.
These findings stand in contrast to results from other study populations involving persons age 24–86 years17 and 39–89 years,6 in which older persons reported a higher frequency of feelings of forgetfulness. Our finding of younger participants reporting a greater frequency of memory worry was expected. Differences in memory and general "forgetfulness" are often generalized as a normative part of senescence, thus "worry" may be minimized among older persons because of a lowering of expectations. In line with this observation, Ponds et al.7 found that forgetfulness did not increase the likelihood of worry or cause an elevation in the perception of memory impairment. Younger participants in the former study also qualified their forgetfulness as psychological, situational, and reversible, whereas older adults often ascribed it to the irreversible process of aging. Thus, comparison of present to past results may be more congruent than discrepant. The combined results can be described as a result of older persons reporting forgetfulness more often and younger persons reporting the perception of memory hindrance and worry because of a perceived inconsistency with a perceived age-related norm. In the study by Bolla et al.6 involving 199 white volunteers from the community, the authors attributed the lower prevalence of forgetfulness among younger participants to an inattention to memory problems. It is plausible to suggest that their results would have been similar to ours if the subject of worry or anxiety surrounding memory problems had been addressed.
A major strength of our study is the generalizability of our findings, as the subjects were selected from the community-dwelling population by using probability sampling. Studies conducted in clinical settings likely capture data for persons who have been experiencing memory difficulty and concerns for some time before bringing them to the attention of their physicians. It is often the insistence and persistence of friends and family members that catalyzes the discussion of memory with a health care provider, rather than the concerns of the patient him- or herself. A stronger association of memory complaints to poor performance on standard neuropsychological tests would be anticipated in clinically based research. However, the evidence to date is mixed, and many clinic-based studies have not included subjects with cognitive impairment or comparison subjects without memory complaints.2 Compared with studies involving a clinically based sample, our research has the advantage of allowing us to determine the utility of a simple probe for identifying persons who may have current memory difficulty that has not necessarily met a threshold for clinical attention specifically addressed to a memory impediment. In the general evaluation of a patient by a general practitioner or other health care provider, inclusion of a one- or two-item probe concerning memory might help to identify persons warranting further neuropsychiatric evaluation, facilitate proper and early diagnosis and treatment, and optimize the prognosis.
Another strength of the present study is that the tests chosen to measure objective functioning are known to measure constructs critical to diagnosis of the dementia syndrome, one of the most common causes of memory disturbance. Further, the prospective nature of the ECA offered a unique opportunity to evaluate the relationship of subjective measures to change in the MMSE score, which, over a considerable time period, can be particularly indicative of underlying pathology. Our findings suggest that those with decrements in cognitive function may have insight about their condition and may rate their memory as poorer than others.
We also acknowledge the limitations of our findings. We recognize the potential for survival and selection bias that may have resulted from including only those persons who were able to participate in all three waves of the study. It is likely that evaluating these associations only in the healthier participants from the original sample would make the final sample more homogeneous and compromise our ability to detect associations, essentially biasing our results toward the null. Because subjective ratings of memory were obtained in wave 3 only, we were unable to assess whether there was a different pattern of attrition among persons who would have had better or worse memory perception or among persons who would have had more or less worry. However, we believe that the robustness of the analysis lies in the size of the sample and that this possibility did not affect the results of the comparisons within our study sample.
Only a few tests were administered, and although these tests are specific for the majority of the diseases affecting memory that are of concern, they do not comprehensively assess all aspects of memory. Also, because the study assessed subjective and objective (delayed recall, discrimination index, current MMSE score) aspects of memory cross-sectionally, we cannot make any conclusions regarding the temporal sequence by which subjectively lower ratings of memory are associated with poorer performance. It is possible that persons with subjectively lower memory ratings have always perceived their memory to be less than average and only recently have begun having problems with memory; conversely problems with memory may affect feelings of self-worth and thus be reflected in lower subjective ratings. Acquisition of subjective ratings only in wave 3 limited our ability to evaluate the predictive value per se for future cognitive decline or neurological disease.
Additional research is needed to evaluate whether subjective memory ratings and memory worry evaluated at younger ages have predictive value for future cognitive decrements and/or neuropathologic diseases. Most of the studies to date have restricted their evaluation to elderly persons. However, in light of the present findings of similar subjective memory rating patterns among younger and older adults and inflated memory worry in younger persons, it would be useful to follow the objective memory test performance and health status of the younger respondents into later age. The concept of a lifelong process of memory impairment and/or dementing illness remains controversial. If it were possible to identify a high-risk population early on, targeted interventions to delay the process could prove most effective.
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ACKNOWLEDGMENTS
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Supported by NIMH grant MH-47447.
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REFERENCES
|
- Riedel-Heller SG, Matschinger H, Angermeyer MC: Do memory complaints indicate the presence of cognitive impairment? results of a field study. Eur Arch Psychiatry Clin Neurosci 1999; 249:197–204[CrossRef][Medline]
- Schofield PW, Marder K, Dooneief G, Jacobs DM, Sano M, Stern Y: Association of subjective memory complaints with subsequent cognitive decline in community-dwelling elderly individuals with baseline cognitive impairment. Am J Psychiatry 1997; 154:609–615[Abstract]
- Tobiansky R, Blizard R, Livingston G, Mann A: The Gospel Oak Study stage IV: the clinical relevance of subjective memory impairment in older people. Psychol Med 1995; 25:779–786[Medline]
- Bassett SS, Folstein MF: Memory complaint, memory performance, and psychiatric diagnosis: a community study. J Geriatr Psychiatry Neurol 1993; 6:105–111
- Jolles J, van Boxtel MP, Ponds RW, Metsemakers JF, Houx PJ: [The Maastricht aging study (MAAS): the longitudinal perspective of cognitive aging.] Tijdschr Gerontol Geriatr 1998; 29:120–129 (Dutch)[Medline]
- Bolla KI, Lindgren KN, Bonaccorsy C: Memory complaints in older adults: fact or fiction? Arch Neurol 1991; 48:61–64[Abstract/Free Full Text]
- Ponds RW, Commissaris KJ, Jolles J: Prevalence and covariates of subjective forgetfulness in a normal population in The Netherlands. Int J Aging Hum Dev 1997; 45:207–221[Medline]
- Di Carlo A, Baldereschi M, Amaducci L, Maggi S, Grigoletto F, Scarlato G, Inzitari D: Cognitive impairment without dementia in older people: prevalence, vascular risk factors, impact on disability: the Italian Longitudinal Study on Aging. J Am Geriatr Soc 2000; 48:775–782[Medline]
- Holmen K, Ericsson K, Winblad B: Quality of life among the elderly: state of mood and loneliness in two selected groups. Scand J Caring Sci 1999; 13:91–95[CrossRef][Medline]
- Barberger-Gateau P, Fabrigoule C: Disability and cognitive impairment in the elderly. Disabil Rehabil 1997; 19:175–193[Medline]
- Black BS, Rabins PV, German PS: Predictors of nursing home placement among elderly public housing residents. Gerontologist 1999; 39:559–568[Abstract]
- Cohen-Mansfield J, Marx MS, Lipson S, Werner P: Predictors of mortality in nursing home residents. J Clin Epidemiol 1999; 52:273–280[CrossRef][Medline]
- Jagger C, Clarke M: Mortality risks in the elderly: five-year follow-up of a total population. Int J Epidemiol 1988; 17:111–114[Abstract/Free Full Text]
- Zelinski EM, Gilewski MJ: Assessment of memory complaints by rating scales and questionnaires. Psychopharmacol Bull 1988; 24:523–529[Medline]
- Zelinski EM, Gilewski MJ, Thompson LW: Do laboratory tests relate to self-assessment of memory ability in the young and old? in New Directions in Memory and Aging. Edited by Poon LW, Fozard JL, Cermak LS, Arenberg D, Thompson LW. Hillsdale, NJ, Lawrence Erlbaum Associates, 1980, pp 519–544
- Jonker C, Launer LJ, Hooijer C, Lindeboom J: Memory complaints and memory impairment in older individuals. J Am Geriatr Soc 1996; 44:44–49[Medline]
- Gagnon M, Dartigues JF, Mazaux JM, Dequae L, Letenneur L, Giroire JM, Barberger-Gateau P: Self-reported memory complaints and memory performance in elderly French community residents: results of the PAQUID Research Program. Neuroepidemiology 1994; 13:145–154[Medline]
- Collins MW, Ables N: Subjective memory complaints and depression in the able elderly. Clin Gerontol 1996; 16:29–54[CrossRef]
- McGlone J, Gupta S, Humphrey D, Oppenheimer S, Mirsen T, Evans DR: Screening for early dementia using memory complaints from patients and relatives. Arch Neurol 1990; 47:1189–1193[Abstract/Free Full Text]
- O'Conner DW, Pollitt PA, Roth M, Brook PB, Reiss BB: Memory complaints and impairment in normal, depressed, and demented elderly persons identified in a community survey. Arch Gen Psychiatry 1990; 47:224–227[Abstract/Free Full Text]
- Derouesne C, Alperovitch A, Arvay N, Migeon P, Moulin F, Vollant M, Rapin JR, Le Poncin M: Memory complaints in the elderly: a study of 367 community-dwelling individuals from 50 to 80 years old. Arch Gerontol Geriatr Suppl 1989; 1:151–163[Medline]
- Kahn RL, Zarit SH, Hilbert NM, Niederehe G: Memory complaint and impairment in the aged: the effect of depression and altered brain function. Arch Gen Psychiatry 1975; 32:1569–1573[Abstract/Free Full Text]
- Williams JM, Little MM, Scates S, Blockman N: Memory complaints and abilities among depressed older adults. J Couns Clin Psychol 1987; 55:595–598[CrossRef][Medline]
- Eaton WW: The NIMH Epidemiologic Catchment Area program: implementation and major findings. Int J Methods Psychiatr Res 1994; 4:103–112
- Lyketsos CG, Chen L-S, Anthony JC: Cognitive decline in adulthood: an 11.5-year follow-up of the Baltimore Epidemiologic Catchment Area study. Am J Psychiatry 1999; 156:58–65[Abstract/Free Full Text]
- Cornoni-Huntley J, Ostfeld AM, Taylor JO, Wallace RB, Blazer D, Berkman LF, Evans DA, Kohout FJ, Lemke JH, Scherr PA, et al: Established populations for epidemiologic studies of the elderly: study design and methodology. Aging (Milano) 1993; 5:27–37[Medline]
- Folstein MF, Folstein SE, McHugh PR: "Mini-Mental State": a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975; 12:189–198[CrossRef][Medline]
- Spreen O: A Compendium of Neuropsychological Tests: Administration, Norms, and Commentary. New York, Oxford University Press, 1991
- Tombaugh TN, McIntyre NJ: The Mini-Mental State Examination: a comprehensive review. J Am Geriatr Soc 1992; 40:922–935[Medline]
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ABSTRACT
INTRODUCTION
