Biomedical subjects

Frederick W Unverzagt

Publications and source records attributed to Frederick W Unverzagt.

14 recordsLinked to original sources

PubMed2006

Long-term effects of cognitive training on everyday functional outcomes in older adults.

CONTEXT: Cognitive training has been shown to improve cognitive abilities in older adults but the effects of cognitive training on everyday function have not been demonstrated. OBJECTIVE: To determine the effects of cognitive training on daily function and durability of training on cognitive abilities. DESIGN, SETTING, AND PARTICIPANTS: Five-year follow-up of a randomized controlled single-blind trial with 4 treatment groups. A volunteer sample of 2832 persons (mean age, 73.6 years; 26% black), living independently in 6 US cities, was recruited from senior housing, community centers, and hospitals and clinics. The study was conducted between April 1998 and December 2004. Five-year follow-up was completed in 67% of the sample. INTERVENTIONS: Ten-session training for memory (verbal episodic memory), reasoning (inductive reasoning), or speed of processing (visual search and identification); 4-session booster training at 11 and 35 months after training in a random sample of those who completed training. MAIN OUTCOME MEASURES: Self-reported and performance-based measures of daily function and cognitive abilities. RESULTS: The reasoning group reported significantly less difficulty in the instrumental activities of daily living (IADL) than the control group (effect size, 0.29; 99% confidence interval [CI], 0.03-0.55). Neither speed of processing training (effect size, 0.26; 99% CI, -0.002 to 0.51) nor memory training (effect size, 0.20; 99% CI, -0.06 to 0.46) had a significant effect on IADL. The booster training for the speed of processing group, but not for the other 2 groups, showed a significant effect on the performance-based functional measure of everyday speed of processing (effect size, 0.30; 99% CI, 0.08-0.52). No booster effects were seen for any of the groups for everyday problem-solving or self-reported difficulty in IADL. Each intervention maintained effects on its specific targeted cognitive ability through 5 years (memory: effect size, 0.23 [99% CI, 0.11-0.35]; reasoning: effect size, 0.26 [99% CI, 0.17-0.35]; speed of processing: effect size, 0.76 [99% CI, 0.62-0.90]). Booster training produced additional improvement with the reasoning intervention for reasoning performance (effect size, 0.28; 99% CI, 0.12-0.43) and the speed of processing intervention for speed of processing performance (effect size, 0.85; 99% CI, 0.61-1.09). CONCLUSIONS: Reasoning training resulted in less functional decline in self-reported IADL. Compared with the control group, cognitive training resulted in improved cognitive abilities specific to the abilities trained that continued 5 years after the initiation of the intervention. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00298558.

Activities of Daily Living↗

PubMed2006

Effectiveness of collaborative care for older adults with Alzheimer disease in primary care: a randomized controlled trial.

CONTEXT: Most older adults with dementia will be cared for by primary care physicians, but the primary care practice environment presents important challenges to providing quality care. OBJECTIVE: To test the effectiveness of a collaborative care model to improve the quality of care for patients with Alzheimer disease. DESIGN, SETTING, AND PATIENTS: Controlled clinical trial of 153 older adults with Alzheimer disease and their caregivers who were randomized by physician to receive collaborative care management (n = 84) or augmented usual care (n = 69) at primary care practices within 2 US university-affiliated health care systems from January 2002 through August 2004. Eligible patients (identified via screening or medical record) met diagnostic criteria for Alzheimer disease and had a self-identified caregiver. INTERVENTION: Intervention patients received 1 year of care management by an interdisciplinary team led by an advanced practice nurse working with the patient's family caregiver and integrated within primary care. The team used standard protocols to initiate treatment and identify, monitor, and treat behavioral and psychological symptoms of dementia, stressing nonpharmacological management. MAIN OUTCOME MEASURES: Neuropsychiatric Inventory (NPI) administered at baseline and at 6, 12, and 18 months. Secondary outcomes included the Cornell Scale for Depression in Dementia (CSDD), cognition, activities of daily living, resource use, and caregiver's depression severity. RESULTS: Initiated by caregivers' reports, 89% of intervention patients triggered at least 1 protocol for behavioral and psychological symptoms of dementia with a mean of 4 per patient from a total of 8 possible protocols. Intervention patients were more likely to receive cholinesterase inhibitors (79.8% vs 55.1%; P = .002) and antidepressants (45.2% vs 27.5%; P = .03). Intervention patients had significantly fewer behavioral and psychological symptoms of dementia as measured by the total NPI score at 12 months (mean difference, -5.6; P = .01) and at 18 months (mean difference, -5.4; P = .01). Intervention caregivers also reported significant improvements in distress as measured by the caregiver NPI at 12 months; at 18 months, caregivers showed improvement in depression as measured by the Patient Health Questionnaire-9. No group differences were found on the CSDD, cognition, activities of daily living, or on rates of hospitalization, nursing home placement, or death. CONCLUSIONS: Collaborative care for the treatment of Alzheimer disease resulted in significant improvement in the quality of care and in behavioral and psychological symptoms of dementia among primary care patients and their caregivers. These improvements were achieved without significantly increasing the use of antipsychotics or sedative-hypnotics. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00246896.

Activities of Daily Living↗

PubMed2006

Association of apolipoprotein E genotype and Alzheimer disease in African Americans.

BACKGROUND: Alzheimer disease (AD) is the most frequent cause of dementia. Even though the incidence of AD in the African American population is similar to or higher than that in persons of European descent, AD in African Americans is understudied. Identification of genetic risk factors in African Americans is essential for understanding the etiology of AD. OBJECTIVE: To determine the effect of apolipoprotein E (APOE) genotype on the risk of AD in elderly African Americans. DESIGN: Population-based longitudinal study of AD. SETTING: Indianapolis, Ind. PARTICIPANTS: African Americans 65 years and older. MAIN OUTCOME MEASURES: APOE genotype and diagnosis of AD. RESULTS: The APOE genotype was determined in 1822 samples. Of these, 690 were clinically evaluated: 318 were normal, and 162 had a diagnosis of AD. The presence of APOE epsilon4 was significantly associated with increased risk of AD (epsilon3/epsilon4: OR, 2.32; 95% confidence interval [CI], 1.41-3.82; and epsilon4/epsilon4: OR, 7.19; 95% CI, 3.00-17.29, compared with the epsilon3/epsilon3 genotype). There was also a significant protective effect with APOE epsilon2 (epsilon2/epsilon2 and epsilon2/epsilon3: OR, 0.42; 95% CI, 0.20-0.89). CONCLUSIONS: These findings are in marked contrast to the lack of association between APOE and AD in the Ibadan, Nigeria, sample of this project. These results suggest that other genetic factors and different environmental influences may play a role in the risk for AD in individuals of African ancestry.

Black or African American↗

PubMed2006

APOE epsilon4 is not associated with Alzheimer's disease in elderly Nigerians.

Since 1992, research teams from Indiana University and the University of Ibadan have been collecting and comparing data from two diverse, elderly populations to identify risk factors for dementia and Alzheimer's disease. Apolipoprotein E (APOE) was genotyped in 2,245 Nigerian samples. Of these, 830 had a diagnosis: 459 were normal, and 140 had dementia including 123 diagnosed with Alzheimer's disease. In contrast with other populations, the APOE epsilon4 allele was not significantly associated with Alzheimer's disease or dementia. This lack of association in the Yoruba might reflect genetic variation, environmental factors, as well as genetic/environmental interactions.

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PubMed2006

Validation analysis of informant's ratings of cognitive function in African Americans and Nigerians.

OBJECTIVES: To examine informant validity using the Community Screening Interview for Dementia (CSI 'D') both cross-sectionally and longitudinally in two very different cultures and to explore the effects of informants and study participants' characteristics on the validity of informants' reports. METHODS: Elderly African Americans age 65 years and older residing in Indianapolis, USA and elderly Yoruba Nigerians age 65 years and older residing in Ibadan, Nigeria were assessed on cognitive functioning using the CSI 'D' at baseline (1992-1993) and five-year follow-up (1997-1998). At baseline, the informant validity in both samples was evaluated against participants' cognitive tests using Pearson correlation and regular regression models. At follow-up, informants ratings on cognitive decline were assessed against participants' cognitive decline scores from baseline to follow-up using biserial correlation and logistic regressions. RESULTS: At baseline, informants' reports on cognitive functioning significantly correlated with cognitive scores in both samples (Indianapolis:r = -0.43, p < 0.001; Ibadan:r = -0.47, p < 0.001). The participant-informant relationships significantly affected the informants' reports in the two samples with different patterns (p = 0.005 for Indianapolis and p < 0.001 for Ibadan) at a given level of cognitive functioning. African Americans spouses reported more cognitive problems, while siblings reported more problems for the Yoruba Nigerians. At follow-up, informants' ratings on cognitive decline significantly correlated with the cognitive decline scores (Indianapolis r = 0.38, p < 0.001; Ibadan r = 0.32, p < 0.001). The characteristics of study participants and informants had little impact on the informants' ratings on cognitive decline. CONCLUSIONS: Informant reports are valid in assessing the cognitive functioning of study participants both cross-sectionally and longitudinally in two very different cultures, languages and environments.

Black or African American↗

PubMed2006

The effects of the ACTIVE cognitive training trial on clinically relevant declines in health-related quality of life.

OBJECTIVES: The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study used three cognitive interventions (memory, reasoning, or speed of processing) in order to improve cognitive abilities. In this article, we evaluate ACTIVE's ability to avoid extensive decline in health-related quality of life (HRQoL). METHODS: ACTIVE enrolled 2,802 adults aged 65 or older and randomized them into one of three cognitive interventions or a no-contact control group. Researchers obtained data on 2,147 participants at the 24-month follow-up. We measured HRQoL by using the eight Short Form-36 scales, and we defined clinically relevant decline on each as a drop of 0.5 standard deviations from baseline. We defined extensive HRQoL decline as clinically relevant drops on four or more Short Form-36 scales, and we assessed this by using multiple logistic regression methods that adjusted for sociodemographic, cognitive, and health status covariates, and incorporated propensity score derived weights in order to adjust for potential attrition bias. RESULTS: We found that 25.0% of ACTIVE participants had extensive HRQoL decline. Participants in the speed-of-processing intervention arm were less likely to have extensive HRQoL decline (adjusted odds ratio = 0.643; p =.004) compared with controls, and participants in the memory and reasoning arms were equivalent to controls (adjusted odds ratios = 1.149 and 1.014, respectively; ps =.322 and.919, respectively). DISCUSSION: Although all three intervention arms improved cognitive ability, only the speed-of-processing arm protected against extensive clinically relevant decline in HRQoL.

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PubMed2005

The Stick Design test: a new measure of visuoconstructional ability.

Visuoconstructional ability is an important domain for assessment in dementia. Use of graphomotor measures dominate this area; however, participants with low education produce results that cannot be easily interpreted. Our objective was to develop and validate a nongraphomotor assessment of visuoconstructional ability for use in dementia evaluations in persons with low or no education. In a longitudinal, population-based study of dementia among Yoruba residents of Ibadan, Nigeria aged 65 years and older, participants underwent clinical assessment with a battery of cognitive tests and consensus diagnosis. Performance on two visuoconstructional tests, Constructional Praxis and Stick Design, were compared. Gender, age, and education affected performance on both tests. The Stick Design test was more acceptable than Constructional Praxis as measured by the number of participants with total test failure (3.9% vs. 15.1%). The Stick Design test was significantly more sensitive to cognitive impairment and dementia than the Constructional Praxis test. We conclude that Stick Design is a reasonable test of visuoconstructional ability in older cohorts with very limited educational exposure and literacy.

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PubMed2005

Implementing a screening and diagnosis program for dementia in primary care.

BACKGROUND: Primary care physicians are positioned to provide early recognition and treatment of dementia. We evaluated the feasibility and utility of a comprehensive screening and diagnosis program for dementia in primary care. METHODS: We screened individuals aged 65 and older attending 7 urban and racially diverse primary care practices in Indianapolis. Dementia was diagnosed according to International Classification of Diseases (ICD)-10 criteria by an expert panel using the results of neuropsychologic testing and information collected from patients, caregivers, and medical records. RESULTS: Among 3,340 patients screened, 434 scored positive but only 227 would agree to a formal diagnostic assessment. Among those who completed the diagnostic assessment, 47% were diagnosed with dementia, 33% had cognitive impairment-no dementia (CIND), and 20% were considered to have no cognitive deficit. The overall estimated prevalence of dementia was 6.0% (95% confidence interval (CI) 5.5% to 6.6%) and the overall estimate of the program cost was $128 per patient screened for dementia and $3,983 per patient diagnosed with dementia. Only 19% of patients with confirmed dementia diagnosis had documentation of dementia in their medical record. CONCLUSIONS: Dementia is common and undiagnosed in primary care. Screening instruments alone have insufficient specificity to establish a valid diagnosis of dementia when used in a comprehensive screening program; these results may not be generalized to older adults presenting with cognitive complaints. Multiple health system and patient-level factors present barriers to this formal assessment and thus render the current standard of care for dementia diagnosis impractical in primary care settings.

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PubMed2004

Selecting pre-screening items for early intervention trials of dementia--a case study.

Our goal was to review and extend statistical methods for discriminating between normal subjects and those with dementia or cognitive impairment. We compared six different methods to one constructed by expert opinion, in their brevity and predictive power. The methods include logistic regression and neural networks, with standard and least absolute shrinkage and selection operator (LASSO) variable selection, as well as decision trees with and without boosting. These methods were applied to the baseline data of a subgroup of subjects in a dementia study, using their screening interview items to predict their clinical diagnosis of normal or non-normal (cognitively impaired or demented). The derived models were then validated on a different subgroup of subjects in the same study who had the screening and clinical diagnosis two to five years later. Performance of different models was compared based on their sensitivity and specificity in the validation sample. Generally, the six statistical methods performed slightly to moderately better than the expert-opinion model. Neural networks generally performed better than the logistic and decision tree models. LASSO improved the performance of logistic and neural network models, but it eliminated few input variables in the neural network. The single decision tree performed at least as well as the standard logistic model, and with fewer items, making it an attractive pre-screening tool. Using the boosting option for decision trees did not substantially improve the performance. We recommend that for each situation, different methods of classification should be attempted to obtain optimal results for a given purpose.

Black or African American↗

PubMed2003

Categorization and recognition performance of a memory-impaired group: evidence for single-system models.

Previous research has demonstrated dissociations between categorization and recognition performance in amnesic patients, supporting the idea that separate memory systems govern these tasks. However, previous research has also demonstrated that these dissociations are predicted by a single-system model that allows for reasonable parameter differences across groups. Generally, previous studies have employed categorization tasks that are less demanding than the recognition tasks. In this study, we distinguish between single-system and multiple-system accounts by testing memory-impaired individuals in a more demanding categorization task. These patients, just like previous amnesic participants, show a dissociation between categorization and recognition when tested in previously employed paradigms. However, they display a categorization deficit when tested in the more challenging categorization task. The results are interpreted as support for a single-system framework in which categorization and recognition depend on one representational system.

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PubMed2002

Effects of cognitive training interventions with older adults: a randomized controlled trial.

CONTEXT: Cognitive function in older adults is related to independent living and need for care. However, few studies have addressed whether improving cognitive functions might have short- or long-term effects on activities related to living independently. OBJECTIVE: To evaluate whether 3 cognitive training interventions improve mental abilities and daily functioning in older, independent-living adults. DESIGN: Randomized, controlled, single-blind trial with recruitment conducted from March 1998 to October 1999 and 2-year follow-up through December 2001. SETTING AND PARTICIPANTS: Volunteer sample of 2832 persons aged 65 to 94 years recruited from senior housing, community centers, and hospital/clinics in 6 metropolitan areas in the United States. INTERVENTIONS: Participants were randomly assigned to 1 of 4 groups: 10-session group training for memory (verbal episodic memory; n = 711), or reasoning (ability to solve problems that follow a serial pattern; n = 705), or speed of processing (visual search and identification; n = 712); or a no-contact control group (n = 704). For the 3 treatment groups, 4-session booster training was offered to a 60% random sample 11 months later. MAIN OUTCOME MEASURES: Cognitive function and cognitively demanding everyday functioning. RESULTS: Thirty participants were incorrectly randomized and were excluded from the analysis. Each intervention improved the targeted cognitive ability compared with baseline, durable to 2 years (P<.001 for all). Eighty-seven percent of speed-, 74% of reasoning-, and 26% of memory-trained participants demonstrated reliable cognitive improvement immediately after the intervention period. Booster training enhanced training gains in speed (P<.001) and reasoning (P<.001) interventions (speed booster, 92%; no booster, 68%; reasoning booster, 72%; no booster, 49%), which were maintained at 2-year follow-up (P<.001 for both). No training effects on everyday functioning were detected at 2 years. CONCLUSIONS: Results support the effectiveness and durability of the cognitive training interventions in improving targeted cognitive abilities. Training effects were of a magnitude equivalent to the amount of decline expected in elderly persons without dementia over 7- to 14-year intervals. Because of minimal functional decline across all groups, longer follow-up is likely required to observe training effects on everyday function.

Activities of Daily Living↗

PubMed2002

Preservation of cognitive function with antihypertensive medications: a longitudinal analysis of a community-based sample of African Americans.

BACKGROUND: Results of previous studies of white older adults suggest that antihypertensive medications preserve cognition. We assessed the long-term effect of antihypertensive medications on cognitive function in a community sample of African American older adults. METHODS: We conducted longitudinal surveys and clinical assessment of cognitive function in a random sample of 2212 community-dwelling African Americans 65 years and older. We identified 1900 participants without evidence of cognitive impairment at baseline, 1617 of whom had subsequent follow-up information, and 946 of whom had blood pressure measurements. Cognitive function was measured at baseline and at 2 and 5 years by means of scores on the Community Screening Instrument for Dementia and neuropsychological and clinical assessment for dementia and cognitive impairment. Prescription and nonprescription medication use was derived from in-home inspection of medications and participant and informant reports. RESULTS: Of 1900 participants, 288 (15.2%) developed incident cognitive impairment. Using logistic regression to control for the effects of age, sex, education, baseline cognitive scores, and hypertension and angina or myocardial infarction, we found that antihypertensive medications reduced the odds of incident cognitive impairment by 38% (odds ratio, 0.62; 95% confidence interval, 0.45-0.84). Corresponding analysis using blood pressure measurements on the subset of participants was inconclusive. CONCLUSION: Antihypertensive medication use is associated with preservation of cognitive function in older African American adults.

Black or African American↗

PubMed2002

Risk of mortality for dementia in a developing country: the Yoruba in Nigeria.

BACKGROUND: Limited data exist on the impact of dementia in developing nations, including its association with mortality. OBJECTIVE: The purpose of this paper is to assess the relationship between dementia and five-year mortality on a community dwelling elderly Yoruba population in the developing country of Nigeria and to compare those results with those from an elderly African-American community in Indianapolis. METHODS: A two-phase design was used to ascertain dementia status in two sites. In the first phase, the Community Screening Instrument for Dementia (CSI-D) was administered. In the second phase, subjects were sampled for the clinical assessment according to their CSI-D performance category. Proportional hazards regression was used to assess the relationship between mortality and cognitive status at both sites after adjusting for demographics and chronic disease conditions. RESULTS: For the entire screened population, poor and intermediate performance on the CSI-D is associated with increased mortality at both sites; however the effect of CSI-D performance did not significantly differ between the two sites. For the clinically assessed sample, dementia was significantly associated with increased mortality at both sites (Ibadan RR = 2.83, Indianapolis RR = 2.05), but the effect was not significantly different across the two sites. CONCLUSION: Dementia resulted in an increased risk of mortality for Yoruba of a magnitude similar to African-Americans suggesting that the impact of dementia on mortality risk may be similar for developing and developed countries.

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PubMed2002

Six-item screener to identify cognitive impairment among potential subjects for clinical research.

OBJECTIVE: To design a brief cognitive screener with acceptable sensitivity and specificity for identifying subjects with cognitive impairment. DESIGN: Cohort one is assembled from a community-based survey coupled with a second-stage diagnostic evaluation using formal diagnostic criteria for dementia. Cohort two is assembled from referrals to a specialty clinic for dementing disorders that completed the same diagnostic evaluation. SETTING: Urban neighborhoods in Indianapolis, Indiana and the Indiana Alzheimer Disease Center. PATIENTS: Cohort one consists of 344 community-dwelling black persons identified from a random sample of 2212 black persons aged 65 and older residing in Indianapolis; cohort two consists of 651 subject referrals to the Alzheimer Disease Center. MEASUREMENTS: Formal diagnostic clinical assessments for dementia including scores on the Mini-mental state examination (MMSE), a six-item screener derived from the MMSE, the Blessed Dementia Rating Scale (BDRS), and the Word List Recall. Based on clinical evaluations, subjects were categorized as no cognitive impairment, cognitive impairment-not demented, or demented. RESULTS: The mean age of the community-based sample was 74.4 years, 59.4% of the sample were women, and the mean years of education was 10.1. The prevalence of dementia in this sample was 4.3% and the prevalence of cognitive impairment was 24.6%. Using a cut-off of three or more errors, the sensitivity and specificity of the six-item screener for a diagnosis of dementia was 88.7 and 88.0, respectively. In the same sample, the corresponding sensitivity and specificity for the MMSE using a cut-off score of 23 was 95.2 and 86.7. The performance of the two scales was comparable across the two populations studied and using either cognitive impairment or dementia as the gold standard. An increasing number of errors on the six-item screener is highly correlated with poorer scores on longer measures of cognitive impairment. CONCLUSIONS: The six-item screener is a brief and reliable instrument for identifying subjects with cognitive impairment and its diagnostic properties are comparable to the full MMSE. It can be administered by telephone or face-to-face interview and is easily scored by a simple summation of errors.

Black or African American↗