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Kenneth Rockwood

Publications and source records attributed to Kenneth Rockwood.

At least 37 records · Page 2Linked to original sources
PubMed2005

Self-referential tags in the discourse of people with Alzheimer's disease.

In a study of the discourse of 100 people with Alzheimer's disease treated for 12 months with donepezil, we observed that, as a group, they used a form of tag, described here as a self-referential tag (SRT), 14 times more frequently than did caregivers. Patients use SRTs to check propositions dependent on episodic memory as in I haven't seen the doctor recently, have I? and to monitor information flow as in I told you that already, didn't I? Based on criteria developed for distinguishing checking from monitoring tags, we document the type and frequency of patients' SRT use in the ACADIE corpus and analyze these in relation to standard measures of cognitive function (Mini Mental State Exam and Alzheimer's Disease Assessment Scale-cognitive sub-scale) at baseline and 12 months. Patients using monitoring SRTs (N=31), with or without checking SRTs, show significantly better cognitive test scores at 12 months, than are seen in patients who never use tags (N=29), or who only use checking tags (N=40). SRT use may be an independent measure of potential treatment responsiveness.

Aged↗
PubMed2005

APOE genotype, vascular risk factors, memory test performance and the five-year risk of vascular cognitive impairment or Alzheimer's disease.

The APOE epsilon4 gene and poor memory test performance have each been associated with an increased risk of developing dementia, but the relationship between these risk factors in predicting dementia is unclear. We examined the multivariate effects of APOE genotype, memory test performance and vascular risk factors in predicting incident Alzheimer's disease (AD) and vascular cognitive impairment (VCI) in the Canadian Study of Health and Aging. Delayed free recall was measured by the Buschke Cued Recall Test (BCRT). The study sample included 223 people who were identified as having no cognitive impairment (NCI) and either APOE epsilon3/epsilon3 or epsilon3/epsilon4 genotypes at the baseline clinical assessment. After 5 years, 182 (82%) still had NCI, 21 developed VCI (9%) and 20 AD (9%). Multivariate analyses demonstrated that APOE epsilon4 increased the risk of AD (OR, 3.48; CI, 1.15-10.48) but not VCI (OR, 0.89; CI, 0.24-3.27). Vascular risk factors increased the risk of VCI (OR, 2.18; CI, 1.36-3.51) but not AD (OR, 0.68; CI, 0.38-1.20). Lower BCRT scores conferred an increased risk of both VCI (OR, 1.75; CI, 1.27-2.42) and AD (OR, 1.86; CI, 1.29-2.67) but attenuated the APOE epsilon4 effect in AD. VCI and AD have different risk profiles and outcomes, but subtle memory difficulties may be an early feature of both.

Aged↗
PubMed2005

A global clinical measure of fitness and frailty in elderly people.

BACKGROUND: There is no single generally accepted clinical definition of frailty. Previously developed tools to assess frailty that have been shown to be predictive of death or need for entry into an institutional facility have not gained acceptance among practising clinicians. We aimed to develop a tool that would be both predictive and easy to use. METHODS: We developed the 7-point Clinical Frailty Scale and applied it and other established tools that measure frailty to 2305 elderly patients who participated in the second stage of the Canadian Study of Health and Aging (CSHA). We followed this cohort prospectively; after 5 years, we determined the ability of the Clinical Frailty Scale to predict death or need for institutional care, and correlated the results with those obtained from other established tools. RESULTS: The CSHA Clinical Frailty Scale was highly correlated (r = 0.80) with the Frailty Index. Each 1-category increment of our scale significantly increased the medium-term risks of death (21.2% within about 70 mo, 95% confidence interval [CI] 12.5%-30.6%) and entry into an institution (23.9%, 95% CI 8.8%-41.2%) in multivariable models that adjusted for age, sex and education. Analyses of receiver operating characteristic curves showed that our Clinical Frailty Scale performed better than measures of cognition, function or comorbidity in assessing risk for death (area under the curve 0.77 for 18-month and 0.70 for 70-month mortality). INTERPRETATION: Frailty is a valid and clinically important construct that is recognizable by physicians. Clinical judgments about frailty can yield useful predictive information.

Aged↗
PubMed2005

Index variables for studying outcomes in vascular cognitive impairment.

Multivariable modeling in dementia risk factor studies is limited by the number of factors that can be analyzed practicably. Index variables, which integrate exposures, can efficiently reduce dimensionality. The Consortium to Investigate Vascular Impairment of Cognition study, a Canadian memory-clinic-based 30-month cohort study of 1,347 patients, used a vascular risk factor index (from 20 exposures) and a vascular clinical profile index (17 items). Patients with vascular cognitive impairment had higher index counts compared to those without cognitive impairment (0.16 +/- 0.11 vs. 0.07 +/- 0.07 for the risk factor index and 0.21 +/- 0.16 vs. 0.09 +/- 0.07 for the clinical profile index; p < 0.05). Both the death rate and the rate of cognitive impairment increased exponentially with the index variable (r > 0.90 for each index). The risk ratio for death was 1.12 (95% CI 1.09-1.15) for each increment of the risk factor index and was 1.23 (95% CI 1.1-1.28) for each increment of the clinical profile index. With each index, the areas under the receiver operating characteristic curves for predicting death and institutionalization ranged from 0.73 +/- 0.01 to 0.75 +/- 0.01. Construction of index variables that integrate multidimensional factors is a promising approach to assessing risk in multi-determined states.

Adult↗
PubMed2005

Inter-rater reliability of delirium rating scales.

Delirium continues to be under-recognized despite use of rating scales with apparently high inter-rater reliability. We analyzed the inter-reliability data of published rating scales for delirium using a standard questionnaire to evaluate if the inter-rater reliability was assessed rigorously. Most studies employed a heterogeneous group of cognitively disordered elderly, however other aspects of inter-rater reliability estimation were less than rigorous. This suggests that the reported reliability may be spuriously high, which may have implications on the ability of clinicians to discriminate delirium from other causes of cognitive impairment in practice. The methodology of assessing inter-rater reliability of delirium scales needs to improve and reliability should be evaluated when the settings of administration change substantially.

Delirium↗
PubMed2005

Incomplete functional recovery after delirium in elderly people: a prospective cohort study.

BACKGROUND: Delirium often has a poor outcome, but why some people have incomplete recovery is not well understood. Our objective was to identify factors associated with short-term (by discharge) and long-term (by 6 month) incomplete recovery of function following delirium. METHODS: In a prospective cohort study of elderly patients with delirium seen by geriatric medicine services, function was assessed at baseline, at hospital discharge and at six months. RESULTS: Of 77 patients, vital and functional status at 6 months was known for 71, of whom 21 (30%) had died. Incomplete functional recovery, defined as > or =10 point decline in the Barthel Index, compared to pre-morbid status, was present in 27 (54%) of the 50 survivors. Factors associated with death or loss of function at hospital discharge were frailty, absence of agitation (hypoactive delirium), a cardiac cause and poor recognition of delirium by the treating service. Frailty, causes other than medications, and poor recognition of delirium by the treating service were associated with death or poor functional recovery at 6 months. CONCLUSION: Pre-existing frailty, cardiac cause of delirium, and poor early recognition by treating physicians are associated with worse outcomes. Many physicians view the adverse outcomes of delirium as intractable. While in some measure this might be true, more skilled care is a potential remedy within their grasp.

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PubMed2005

Evaluation of a frailty index based on a comprehensive geriatric assessment in a population based study of elderly Canadians.

BACKGROUND AND AIMS: Objectives were to develop a frailty index (FI) based on a standard comprehensive geriatric assessment (CGA) derived from a clinical examination; to assess the validity of the FI-CGA and to compare its precision with other frailty measures. METHODS DESIGN: Secondary analysis of a prospective cohort study, with five-year follow-up data. SETTING: Second phase of the Canadian Study of Health and Aging (CSHA-2); clinical examinations were performed in clinics, nursing homes, and patients' homes. PARTICIPANTS: People selected (as either cognitively impaired cases or unimpaired controls) to receive the CSHA-2 clinical examination (n = 2305; women = 1431). MEASUREMENTS: Clinical and performance-based measures and diagnostic data were extracted to correspond to the 10 impairment domains and the single comorbidity domain of a CGA. The proportion of deficits accumulated in each domain was calculated to yield the FI-CGA. The FI-CGA was validated and its predictive ability compared with other frailty measures. RESULTS: Within the seven grades of fitness/frailty identified, subjects with greater frailty were older, less educated, and more likely to be women. The FI-CGA correlated highly with a previously validated, empirically-derived frailty index (r = 0.76). Frailty was associated with higher risk of death (for each increment in frailty, the hazard ratio, adjusted for age, sex and education, was 1.23 (95% CI 1.18-1.29) and institutionalization (HR 1.20; 1.10-1.32). CONCLUSIONS: In a population survey, the FI-CGA is a valid means of quantifying frailty from routinely collected data.

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PubMed2005

Dementia of acute onset in the Canadian Study of Health and Aging.

BACKGROUND: Although most people with dementia experience an insidious onset of symptoms, in some cases onset can be acute. The importance of acute onset is unclear. Some reports suggest that it portends a worse course. METHODS: We performed a secondary analysis of the clinical examination cohort (n=2914) of the Canadian Study of Health and Aging (CSHA). We defined "acute onset of dementia" from the Cambridge Examination for Mental Disorders in the Elderly (CAMDEX) questionnaire, conducted with an informant. People with dementia of acute onset were compared to those with dementia of insidious onset for development of adverse outcomes of death and institutionalization over 5 years. RESULTS: Of the 1132 people who had dementia, 130 (11.5%) met criteria for acute onset. Compared with gradual-onset dementia patients, those with acute-onset dementia were more often men (42% vs. 30%, p < 0.05), resided in nursing homes (75% vs. 63%, p< 0.05), had vascular risk factors (72% vs. 47%, p < 0.05), and a Hachinski Ischemia Scale (HIS) score > or = 7 (64% vs. 19%, p < 0.05). More patients with dementia of acute onset than gradual onset were diagnosed with vascular dementia (55% vs. 13%; p < 0.05). Adjusted hazard ratios (HRs) for survival and institutionalization in the acute-onset group were 0.93 [95% confidence interval (CI) 0.7-1.2] and 0.76 (95% CI 0.4-1.3), respectively, compared with the gradual-onset group. CONCLUSIONS: People with acute-onset dementia had more vascular risk factors than those with gradual-onset dementia across all dementia diagnoses, and lower risks of institutionalization but worse survival. Routine inquiry about the onset of dementia might help to better clarify prognoses in patients with dementia.

Acute Disease↗
PubMed2005

What would make a definition of frailty successful?

At present, frailty is defined variably. Some consensus on a definition is likely to emerge, but the basis for a successful definition needs to be explored. Here, a classic approach to validation is proposed: a successful definition of frailty should be multifactorial but must also manage the many factors in a way that takes their interactions into account. It is likely to be correlated with disability, co-morbidity and self-rated health, and should identify a group that is vulnerable to adverse outcomes. Ideally, it should also be susceptible to animal modelling. In that frailty and age are so bound together, it is also likely that there will be some age at which virtually all people will be frail, by any definition. Apart from being valid, the success of any definition of frailty will depend on it being useful to researchers and clinicians. The need for progress on our understanding of frailty is evident, but for now, there is insufficient evidence to accept a single definition of frailty.

Aged↗
PubMed2005

Relative fitness and frailty of elderly men and women in developed countries and their relationship with mortality.

OBJECTIVES: To investigate the relationship between accumulated health-related problems (deficits), which define a frailty index in older adults, and mortality in population-based and clinical/institutional-based samples. DESIGN: Cross-sectional and cohort studies. SETTING: Seven population-based and four clinical/institutional surveys in four developed countries. PARTICIPANTS: Thirty-six thousand four hundred twenty-four people (58.5% women) aged 65 and older. MEASUREMENTS: A frailty index was constructed as a proportion of all potential deficits (symptoms, signs, laboratory abnormalities, disabilities) expressed in a given individual. Relative frailty is defined as a proportion of deficits greater than average for age. Measures of deficits differed across the countries but included common elements. RESULTS: In each country, community-dwelling elderly people accumulated deficits at about 3% per year. By contrast, people from clinical/institutional samples showed no relationship between frailty and age. Relative fitness/frailty in both sexes was highly correlated (correlation coefficient >0.95, P<.001) with mortality, although women, at any given age, were frailer and had lower mortality. On average, each unit increase in deficits increased by 4% the hazard rate for mortality (95% confidence interval=0.02-0.06). CONCLUSION: Relative fitness and frailty can be defined in relation to deficit accumulation. In population studies from developed countries, deficit accumulation is robustly associated with mortality and with age. In samples (e.g., clinical/institutional) in which most people are frail, there is no relationship with age, suggesting that there are maximal values of deficit accumulation beyond which survival is unlikely.

Age Distribution↗
PubMed2004

Incidence of and risk factors for nodding off at scientific sessions.

We conducted a surreptitious, prospective, cohort study to explore how often physicians nod off during scientific meetings and to examine risk factors for nodding off. After counting the number of heads falling forward during 2 days of lectures, we calculated the incidence density curves for nodding-off episodes per lecture (NOELs) and assessed risk factors using logistic regression analysis. In this article we report our eye-opening results and suggest ways speakers can try to avoid losing their audience.

Boredom↗
PubMed2004

Rates of influenza vaccination in older adults and factors associated with vaccine use: a secondary analysis of the Canadian Study of Health and Aging.

BACKGROUND: Influenza vaccination has been shown to reduce morbidity and mortality in the older adult population. In Canada, vaccination rates remain suboptimal. We identified factors predictive of influenza vaccination, in order to determine which segments of the older adult population might be targeted to increase coverage in influenza vaccination programs. METHODS: The Canadian Study of Health and Aging (CSHA) is a population-based national cohort study of 10263 older adults (>/= 65) conducted in 1991. We used data from the 5007 community-dwelling participants in the CSHA without dementia for whom self-reported influenza vaccination status is known. RESULTS: Of 5007 respondents, 2763 (55.2%) reported having received an influenza vaccination within the previous 2 years. The largest predictive factors for flu vaccination included: being married (57.4 vs. 52.6%, p = 0.0007), having attained a higher education (11.0 vs. 10.3 years, p < 0.0001), smoking (57.1% vs. 52.9%, p = 0.0032), more alcohol use (57.9% of those who drank more vs. 53.2% of those who drank less, p = 0.001), poorer self-rated health (54.1% of those with good self-rated health vs. 60.6% of those with poor self-rated health, p = 0.0006), regular exercise (56.8% vs. 52.0%, p = 0.001), and urban living (55.8% vs. 51.0%, p = 0.03). While many other differences were statistically significant, most were small (e.g. mean age 75.1 vs. 74.6 years for immunized vs. unimmunized older adults, p = 0.006, higher Modified Mini Mental Status Examination score (89.9 vs. 89.1, p < 0.0001), higher comorbidity (2.7 vs. 2.3 comorbidities, p < 0.0001). Residents of Ontario were more likely (64.6%) to report vaccination (p < 0.0001), while those living in Quebec were less likely to do so (48.2%, p < 0.0001). Factors retaining significance in a multivariate analysis included older age, higher education, married status, drinking alcohol, smoking, engaging in regular exercise, and having higher comorbidity. CONCLUSIONS: The vaccination rate in this sample, in whom influenza vaccination is indicated, was low (55.2%). Even in a publicly administered health care setting, influenza vaccination did not reach an important proportion of the elderly population. Whether these differences reflect patient preference or access remains to be determined.

Aged↗
PubMed2004

Emerging therapies for vascular dementia and vascular cognitive impairment.

BACKGROUND: Cerebrovascular disease (CVD) and ischemic brain injury secondary to cardiovascular disease are common causes of dementia and cognitive decline in the elderly. CVD also contributes to cognitive loss in Alzheimer disease (AD). SUMMARY: Progress in understanding vascular cognitive impairment (VCI) and vascular dementia (VaD) has resulted in promising symptomatic and preventive treatments. Cholinergic deficits in VaD due to ischemia of basal forebrain nuclei and cholinergic pathways can be treated with cholinesterase inhibitors used in AD. Controlled clinical trials with donepezil and galantamine in patients with VaD, as well as in patients with AD plus CVD, have demonstrated improvement in cognition, behavior, and activities of daily living. The N-methyl-D-aspartate receptor antagonist memantine stabilized progression of VaD compared with placebo. Primary and secondary stroke prevention, in particular with control of hypertension and hyperlipidemia, can decrease VaD incidence. CONCLUSIONS: From a public health viewpoint, recognition of VCI before the development of dementia and correction of vascular burden on the brain may lead to a global decrease of incident dementia.

Carbamates↗
PubMed2004

Conceptualization of mild cognitive impairment: a review.

BACKGROUND: Several factors have prompted renewed interest in the concept of declines in cognitive function that occur in association with aging, in particular the area between normal cognition and dementia. We review the changing conceptualization of what has come to be known as mild cognitive impairment (MCI) in an effort to identify recent developments and highlight areas of controversy. METHODS: Standard MEDLINE search for relevant English-language publications on mild cognitive impairment and its associated terms, supplemented by hand searches of pertinent reference lists. RESULTS: Many conditions cause cognitive impairment which does not meet current criteria for dementia. Within this heterogenous group, termed 'Cognitive Impairment, No Dementia' (CIND), there are disorders associated with an increased risk of progression to dementia. Still, the conceptualization of these latter disorders remains in flux, with variability around assumptions about aging, the relationship between impairment and disease, and how concomitant functional impairment is classified. Amongst patients with MCI, especially its amnestic form, many will progress to Alzheimer's disease (AD). In contrast with clinic-based studies, where progression is more uniform, population-based studies suggest that the MCI classification is unstable in that context. In addition to Amnestic Mild Cognitive Impairment (AMCI), other syndromes exist and can progress to dementia. For example, an identifiable group with vascular cognitive impairment without dementia shows a higher risk of progression to vascular dementia, Alzheimer's disease and mixed dementia. CONCLUSIONS: Recent attempts to profile patients at an increased risk of dementia suggest that this can be done in skilled hands, especially in people whose symptoms prompt them to seek medical attention. Whether these people actually have early AD remains to be determined. The more narrowly defined MCI profiles need to be understood in a population context of CIND.

Aged↗
PubMed2004

Potential treatment effects of donepezil not detected in Alzheimer's disease clinical trials: a physician survey.

OBJECTIVES: Clinical trials of the cholinesterase inhibitor donepezil have used standard psychometric tools to evaluate treatment efficacy. These trials, however, appear not to capture clinically demonstrable, but otherwise unmeasured, beneficial treatment effects. We sought to identify and categorize clinically recognizable effects of donepezil treatment in Alzheimer's disease. METHODS: A list of potential effects was developed using clinical trials data and the experience of an expert panel. These were incorporated in a questionnaire, which was tested with a focus group, revised and then used in a postal survey of physicians. Data were classified by cognitive domain, and reviewed by a second panel. RESULTS: Items that were most often rated as being improved were related to frontal systems function, including attentional capacity and initiative. Behavioral symptoms that were among the highest rated items were apathy, mood, and agitation. The top two other items were social interactions and involvement in domestic activities. Of the top ten symptomatic treatment effects, only four appeared to be readily identified by current standard measures. CONCLUSIONS: Physicians recognize as important several treatment effects that are not well captured by current standard measures. New methods are needed to capture such effects, which also have the potential to offer insight into the neurobiology of the human cholinergic system.

Activities of Daily Living↗