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Biomedical subjects

David B Hogan

Publications and source records attributed to David B Hogan.

30 records · Page 2Linked to original sources
PubMed2004

Prevalence, attributes, and outcomes of fitness and frailty in community-dwelling older adults: report from the Canadian study of health and aging.

BACKGROUND: Frailty and fitness are important attributes of older persons, but population samples of their prevalence, attributes, and outcomes are limited. METHODS: The authors report data from the community-dwelling sample (n = 9008) of the Canadian Study of Health and Aging, a representative, 5-year prospective cohort study. Fitness and frailty were determined by self-reported exercise and function level and testing of cognition. RESULTS: Among the community-dwelling elderly population, 171 per 1000 were very fit and 12 per 1000 were very frail. Frailty increased with age, so that by age 85 years and older, 44 per 1000 were very frail. The risk for adverse health outcomes increased markedly with frailty: Compared with older adults who exercise, those who were moderately or severely frail had a relative risk for institutionalization of 8.6 (95% confidence interval, 4.9 to 15.2) and for death of 7.3 (95% confidence interval, 4.7 to 11.4). These risks persist after adjustments for age, sex, comorbid conditions, and poor self-rated health. At all ages, men reported higher levels of exercise and less frailty compared with women. Decreased fitness and increased frailty were also associated with poor self-ratings of health (42% in the most frail vs 7% in the most fit), more comorbid illnesses (6 vs 3), and more social isolation (34% vs 29%). CONCLUSIONS: Fitness and frailty form a continuum and predict survival. Exercise influences survival, even in old age. Relative fitness and frailty can be determined quickly in a clinical setting, are potentially useful markers of the risk for adverse health outcomes, and add value to traditional medical assessments that focus on diagnoses.

Aged↗
PubMed2004

Does self-rated health predict survival in older persons with cognitive impairment?

OBJECTIVES: To determine whether baseline self-rated health (SRH) independently predicted survival in an older Canadian population and to investigate the role of cognition on the SRH-mortality relationship. DESIGN: Population-based prospective cohort study. SETTING: Ten Canadian provinces, community-based. PARTICIPANTS: A total of 8,697 community-dwelling participants aged 65 and older. MEASUREMENTS: Self-reported measures of overall health, physical function, comorbidities, and demographic characteristics were obtained by interview. Cognitive ability was ascertained using the Modified Mini-Mental State Examination (3MS). Participants were followed for their survival status from the initial interview in 1991 until October 31, 1996. RESULTS: Subjects with reports of poor SRH were significantly more likely to die during follow-up than those reporting good SRH, after adjusting for relevant covariates (adjusted hazard ratio (AHR)=1.38, 95% confidence interval (CI)=1.24-1.53). SRH was also related to other measures of health status across levels of cognitive impairment. SRH remained a significant predictor of mortality in subjects with mild to moderate cognitive impairment (AHR=1.26, 95% CI=1.01-1.59) but not in those with severe cognitive impairment (AHR=1.00, 95% CI=0.76-1.31). CONCLUSION: This study supports the utility of SRH assessments in predicting survival of individuals with mild to moderate cognitive impairment. The findings highlight the potential role of complex cognitive processes underlying the SRH-mortality relationship.

Aged↗
PubMed2003

Measurement, correlates, and health outcomes of medication adherence among seniors.

OBJECTIVE: To provide a comprehensive review of the literature on the measurement, correlates, and health outcomes of medication adherence among community-dwelling older adults. DATA SOURCES: Searches of MEDLINE, PubMed, and International Pharmaceutical Abstracts databases for English-language literature (1966-December 2002) were conducted using one or more of the following terms: elderly, adherence/nonadherence, compliance/noncompliance, medication/drug, methodology/measurement, and hospitalization. STUDY SELECTION AND DATA EXTRACTION: From the above search, studies of medication adherence in community-dwelling seniors were selected for review along with relevant publications from the reference lists of articles identified in the initial database search. DATA SYNTHESIS: Although several methods are available for the assessment of adherence, accurate measurement continues to be difficult. The available evidence suggests that polypharmacy and poor patient-healthcare provider relationships (including the use of multiple providers) may be major determinants of nonadherence among older persons, with the impact of most sociodemographic factors being negligible. There is little consensus regarding other determinants of nonadherence. Relatively few high-quality investigations have examined the associations between nonadherence and subsequent health outcomes. Available data provide some support for increased health risks with nonadherence. However, interventions to improve adherence have seldom demonstrated positive effects on health outcomes. CONCLUSIONS: There are few empirical data to support a simple systematic descriptor of the nonadherent patient. The inconsistencies across studies may be attributable, in part, to the inherent difficulties involved in the measurement of a behavioral risk factor such as nonadherence. Future research in this area would be strengthened by incorporation of detailed assessments of patient-reported reasons for nonadherence, the appropriateness of drug regimens, and the effect of nonadherence on health outcomes.

Activities of Daily Living↗
PubMed2003

The Consortium to Investigate Vascular Impairment of Cognition: methods and first findings.

BACKGROUND: The Consortium to Investigate Vascular Impairment of Cognition (CIVIC) is a Canadian, multi-centre, clinic-based prospective cohort study of patients with Vascular Cognitive Impairment (VCI). We report its organization and the impact of diagnostic criteria on the study of VCI. METHODS: Nine memory disability clinics enrolled patients and recorded their usual investigations and care. A case report form included all vascular dementia (VaD) individual criteria for each of four sets (National Institute of Neurological Disorders and Stroke (NINDS-AIREN), Alzheimer's Disease Diagnostic Treatment Centers (ADDTC), the ICD-10 Classification of Mental and Behavioural Disorders (ICD-10), and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV)) of consensus-based diagnostic criteria and for the Hachinski Ischemia Score (HIS). Investigators, having completed the case report form, were asked to make a clinical judgement about the cognitive diagnosis based on the best available information, including neuroimaging. RESULTS: Of 1,347 patients (mean age 72 years; 56% women), 846 (63%) were diagnosed with dementia and 324 (24%) were diagnosed with VCI. The proportion of patients diagnosed with VaD by the diagnostic criteria was: 23.9% (n = 322) by DSM-IV, 10.2% (n = 137) by HIS, 4.3% (n = 58) by ICD-10, 3.8% (n = 51) by ADTCC, and 3.6% (n = 48) by NINDS-AIREN. Judged against a clinical diagnosis of VaD, the sensitivity/specificity of each was: DSM-IV (0.77/0.80); HIS (0.41/0.92); ICD-10 (0.29/0.98); ADTCC (0.24/0.98); NINDS-AIREN (0.42/0.995). Compared with a clinical diagnosis of VCI, sensitivities were lower for the diagnostic criteria, reflecting the exclusion of patients who did not have dementia. CONCLUSIONS: Consensus-based criteria for VaD omit patients who do not meet dementia criteria that are modeled on Alzheimer's disease. Even for patients who do, the proportion identified with VaD varies widely. Criteria based on empirical analyses need to be developed and validated.

Adult↗
PubMed2003

Prevalence and potential consequences of benzodiazepine use in senior citizens: results from the Canadian Study of Health and Aging.

OBJECTIVES: The aim of this study was to evaluate changes in benzodiazepine use over time, and the association between benzodiazepine use and select outcomes. DESIGN: A five-year longitudinal cohort study in subjects 65 years of age and older. SETTING: Select urban communities and institutions across Canada with senior citizens. PARTICIPANTS: Subjects who were first seen in 1990 to 1991, recontacted in 1996, and agreed to undergo a second clinical examination. Mortality rates were based on the initial 2914 subjects enrolled. MEASUREMENTS: Number and type of medications used. Outcomes (mortality, incident institutionalization, change in cognition, depression, function, self-rated health) associated with benzodiazepine use. Logistic regression to predict outcomes and pattern of benzodiazepine use. RESULTS: Mean number of medications being taken by senior citizens increased to 5.8 from 3.9. The proportion of subjects using benzodiazepines at time 1 and time 2 was similar (26.4% versus 25.2%). Affect, self-rated health, cognition, function and incident institutionalization were significantly associated with benzodiazepine use. Subjects with a depressed mood were more likely to be prescribed a benzodiazepine (37%) than an antidepressant (26.9%). CONCLUSION: Benzodiazepines were associated with a number of adverse outcomes. The relative benefits and risks of benzodiazepine use in an older population should be re-examined.

Activities of Daily Living↗
PubMed2002

Use of lipid-lowering agents, indication bias, and the risk of dementia in community-dwelling elderly people.

BACKGROUND: Recent reports suggest a possibly protective effect for statins in patients with Alzheimer disease. This association could be due to indication bias, i.e., people who elect to take lipid-lowering agents (LLAs) may be healthier than those who do not, so that it may be these other health factors that explain their lower risk of dementia. OBJECTIVES: To examine the association between the use of LLAs and dementia, adjusting for other markers of health, and to investigate factors associated with LLA use. DESIGN: A cohort study of LLA use and a case-control study of dementia in relation to LLA use, in a secondary analysis of the Canadian Study of Health and Aging. SETTING: A nationally representative population-based survey of Canadians 65 years and older. PARTICIPANTS: To examine features associated with statin use, we evaluated data on 2305 people for whom health information, drug use, and cognitive status were known. To examine the relationship between LLA use and dementia, we selected incident cases of dementia (n = 492, of whom 326 had Alzheimer disease) that occurred between the first and second waves of the study. Control subjects were 823 persons examined during the first and second phases of the Canadian Study of Health and Aging who had no cognitive impairment. RESULTS: Use of LLAs was significantly (P<.001) more common in younger (65-79 years) than in older (> or = 80 years) people. It was not associated with other factors indicating a healthy lifestyle, but was associated with a history of smoking and hypertension. Use of statins and other LLAs reduced the risk of Alzheimer disease in subjects younger than 80 years, an effect that persisted after adjustment for sex, educational level, and self-rated health (odds ratio, 0.26; 95% confidence interval, 0.08-0.88). There was no significant effect in subjects 80 years and older. CONCLUSIONS: While the possibility of indication bias in the original observations cannot be excluded, it was not demonstrated in LLA use in this study. Lipid-lowering agent use was associated with a lower risk of dementia, and specifically of Alzheimer disease, in those younger than 80 years. Further research is warranted.

Age Factors↗
PubMed2002

Progress in clinical neurosciences: Treatment of Alzheimer's disease and other dementias--review and comparison of the cholinesterase inhibitors.

BACKGROUND: Alzheimer's disease (AD) is the most common cause of dementia in older adults. Acceptance of the cholinergic hypothesis led to a search for medications which could enhance central cholinergic activity in this condition. There are now three cholinesterase inhibitors available for the treatment of AD in Canada. OBJECTIVES: To review the currently available cholinesterase inhibitors approved for the treatment of AD in Canada and to provide guidance on who and how to treat with these agents. RESULTS: Donepezil, rivastigmine, and galantamine are approved for the treatment of AD in Canada. In clinical trails, patients with mild to moderate AD treated with these agents experienced modest improvements in cognition, function, behaviour, and/or global clinical state. The magnitude of benefits seen with each agent appeared to be similar. While to date, there is no convincing evidence that one is more efficacious or effective, they do differ in their pharmacokinetics, additional mechanisms of action, and side effect profiles. Therefore, the selection of agent will be based on considerations such as side effect profiles, ease of administration, personal familiarity/experience, and beliefs about the importance of the noted differences in their pharmacokinetics and additional mechanisms of action. CONCLUSION: We believe that these agents should be offered to all individuals with a mild to moderate dementia where Alzheimer's pathology is felt to be a contributing factor. We view all three available cholinesterase inhibitors as first-line drugs.

Alzheimer Disease↗
PubMed2002

Serum folate levels and subsequent adverse cerebrovascular outcomes in elderly persons.

Recent epidemiologic studies have shown an association between low serum folate levels and risk of vascular disease, including stroke and various types of vascular cognitive impairment. We examined data from the Canadian Study of Health and Aging (CSHA), a population-based, prospective 5-year investigation of the epidemiology of dementia among Canadians aged 65+ years. The risk of an adverse cerebrovascular event (including vascular dementia, vascular cognitive impairment, or fatal stroke) during follow-up, was assessed according to serum folate quartiles among subjects with no evidence of dementia at baseline (n = 369). After adjusting for certain covariates, including cardiovascular disease and nutritional indices, education, smoking and baseline cognitive status, the risk estimate for an adverse cerebrovascular event associated with the lowest folate quartile compared with the highest quartile was OR 2.42 (95% CI 1.04-5.61). Results from stratified analyses also showed that relatively low serum folate was associated with a significantly higher risk of an adverse cerebrovascular event among female (OR 4.02, 95% CI 1.37-11.81) but not male (OR 1.02, 95% CI 0.25-4.13) subjects. Among the total sample, there was a consistent trend toward poorer health and cognitive outcomes during follow-up (including mortality, cognitive decline and dementia) among those in the lowest folate quartile compared with the highest quartile. Low serum folate levels are independently associated with a significantly higher risk of an adverse cerebrovascular event, including vascular dementia and stroke death, among older, cognitively vulnerable persons.

Aged↗
PubMedDate not supplied

Prognostic factors for functional independence in older adults with mild dementia: results from the canadian study of health and aging.

We investigated the prevalence of and prognostic factors for functional independence in personal activities of daily living in a population-based sample of 90 seniors with mild dementia from the Canadian Study of Health and Aging. Personal activities of daily living were assessed from the report of proxy respondents at baseline and at the 5-year follow-up (or retrospectively if death had occurred). Sixteen (17.8% of the total group of 90) subjects maintained their personal activities of daily living independence over the full 5-year period or up to 3 months before death (15.1% if the four subjects reclassified as not demented at the second wave are excluded). An age of 75-84 years (vs. those 65-74 years of age and 85+ years of age; odds ratio 12.9, 95% confidence interval 2.7, 112.7), the absence of gait-balance-movement problems (odds ratio 5.2, 95% confidence interval 1.3, 25.8), the presence of extrapyramidal signs (odds ratio 9.5), and fewer years of formal education (odds ratio 3.6) were favorable prognostic factors in our multivariate modeling. An absence of sensory problems was a statistically significant favorable prognostic factor in bivariate analysis. Prior studies on the time required for patients with dementia to progress to functional milestones used clinic-based samples. Our findings, which have potential public health implications, need to be confirmed and expanded upon.

Activities of Daily Living↗