Measurement of the influence of the physical environment on adverse health outcomes: technical report from the Canadian Study of Health and Aging

A paucity of information exists to characterize the relationship between the health status of elderly people and their physical environment. The Canadian Study of Health and Aging (CSHA) is a multicenter study of the distribution of dementia among community-dwelling and institutionalized Canadians aged 65 years and older. The study also provides the opportunity to examine issues such as the physical environment which may be related to the health of elderly people. Six items were used to assess the cleanliness, neatness, and maintenance of the inside and outside of the homes of 8,134 community-dwelling individuals. Data were also obtained to evaluate cognition, physical health, and functional capacity. Five years after the original survey, information pertaining to subsequent institutionalization and/or mortality was obtained. A significant relationship was found between classification of physical environment and the outcomes of institutionalization and mortality. The likelihood of both adverse outcomes was notably higher for individuals living in a "less than ideally maintained environment" compared to an "ideally maintained environment." Limitations of the six items used to assess the physical environment and ways in which to improve the sensitivity of the items, consequently avoiding measurement bias, are discussed.

Reliability and validity of questions about exercise in the Canadian Study of Health and Aging

Regular exercise in elderly people has beneficial health effects. We examined exercise frequency and intensity from the Canadian Study of Health and Aging Risk Factor Questionnaire (RFQ). The reliability and validity of these two questions individually, and when combined to form a scale, are reported. Agreement between the self-administered RFQ and an interviewer-administered Add-on Study was examined using intraclass correlations, which were 0.80 for frequency (95% CI 0.77-0.82, p < .001) and 0.75 for intensity (95% CI 0.71-0.78, p = .012). Individuals reporting high levels of exercise frequency, intensity, and a combination of the two showed a smaller proportion of adverse health markers than those reporting no regular exercise. Predictive validity assessed by Cox proportional hazards modeling of mortality showed that the high and moderate levels of frequency, intensity, and combined exercise groups differed significantly (all p < .001) from the no exercise group. We have found that these exercise questions, though simple, appear reliable and valid. The finding that even comparatively crude exercise questions can demonstrate an important relationship to death suggests that the signal for exercise is a strong one, and future studies should seek to better examine mechanisms by which exercise benefit is conferred.

Assessing hypertension in the Canadian Study of Health and Aging

We investigated the self-report hypertension variables in the CSHA, recorded in the screening questionnaire and the Self-Administered Risk Factor (SARF) questionnaire. The two questions showed high agreement (phi coefficient 0.83). Each was modestly but significantly associated with other simultaneous reports of heart disease and stroke, and with subsequent mortality. Only the SARF asked questions about treatment; controlling for treatment effects, five-year survival was longest among those with no hypertension and no treatment (mean survival time 1,645 days; 95% CI 1,632 to 1,658), and shortest for those with no reported hypertension who were receiving "antihypertensive" medications presumably prescribed for other cardiovascular disease (mean survival time 1,496 days; 95% CI 1,457 to 1,535). The SARF questions incorporating high blood pressure and treatment appear preferable to assess the risks associated with hypertension.

Linkage of the Canadian Study of Health and Aging to provincial administrative health care databases in Nova Scotia

The Canadian Study of Health and Aging (CSHA) was a cohort study that included 528 Nova Scotian community-dwelling participants. Linkage of CSHA and provincial Medical Services Insurance (MSI) data enabled examination of health care utilization in this subsample. This article discusses methodological and ethical issues of database linkage and explores variation in the use of health services by demographic variables and health status. Utilization over 24 months following baseline was extracted from MSI's physician claims, hospital discharge abstracts, and Pharmacare claims databases. Twenty-nine subjects refused consent for access to their MSI file; health card numbers for three others could not be retrieved. A significant difference in healthcare use by age and self-rated health was revealed. Linkage of population-based data with provincial administrative health care databases has the potential to guide health care planning and resource allocation. This process must include steps to ensure protection of confidentiality. Standard practices for linkage consent and routine follow-up should be adopted. The Canadian Study of Health and Aging (CSHA) began in 1991-92 to explore dementia, frailty, and adverse health outcomes (Canadian Study of Health and Aging Working Group, 1994). The original CSHA proposal included linkage to provincial administrative health care databases by the individual CSHA study centers to enhance information on health care utilization and outcomes of study participants. In Nova Scotia, the Medical Services Insurance (MSI) administration, which drew the sampling frame for the original CSHA, did not retain the list of corresponding health card numbers. Furthermore, consent for this access was not asked of participants at the time of the first interview. The objectives of this study reported here were to examine the feasibility and ethical considerations of linking data from the CSHA to MSI utilization data, and to explore variation in health services use by demographic and health status characteristics in the Nova Scotia community cohort.

Defining parkinsonism in the Canadian Study of Health and Aging

This study sought an operational definition of parkinsonism in elderly people (n = 2,914) who underwent a clinical examination in the Canadian Study of Health and Aging (CSHA). Parkinsonism was defined as having two of the following features: (1) bradykinesia of face or limbs, (2) resting tremor, (3) rigidity, and (4) abnormality of gait and posture. The association of parkinsonism with other parkinsonian-related features (prior diagnosis of Parkinson's disease, use of drugs with extrapyramidal side effects, and use of antiparkinsonian medications) and variables not expected to be related to parkinsonism (stroke and Hachinski score > 5) was determined. Parkinsonism was identified in 337 people (11.6%). It was significantly more likely with other parkinsonian-related characteristics, and was not associated with a history of stroke, but was slightly higher among those subjects with a Hachinski score > 5. Posture and gait abnormalities were significantly associated with other parkinsonian-related variables, but were also more common among subjects with stroke-related features. When the gait and posture disturbance category was excluded as a parkinsonian sign, the narrower definition was more specific but less sensitive in detecting cases with a clinical diagnosis of Parkinson's disease. Despite limitations, the approach presented in this article is a valid method to operationalize parkinsonism from the dataset.

Use of the chronic disease score to measure comorbidity in the Canadian Study of Health and Aging

Most older adults have multiple chronic diseases. Consideration of these conditions can improve the performance of statistical models in epidemiological analyses. The Chronic Disease Score (CDS) is a measure of comorbidity derived from medication usage, which may have some advantages over measures derived from other sources. The calculation of the CDS from data contained in the Canadian Study of Health and Aging (CSHA) is described. This measure can be used to estimate comorbidity within the CSHA database.

The effect of the living situation on the severity of dementia at diagnosis

INTRODUCTION

Previous studies have shown that social determinants not directly involved in the disease process may be implicated in the timing of dementia diagnosis. This study explores the relationship between a patient's living situation and the severity of dementia at diagnosis.

METHODS

Data were collected from the baseline interviews of 1,325 patients with cognitive decline enrolled in the Consortium for the Investigation of Vascular Impairment of Cognition study. Data collected included: age, sex, living situation and scores on the Mini-Mental State Examination (MMSE), Global Deterioration Scale (GDS), the Functional Rating Scale (FRS), the Disability Assessment for Dementia (DAD) scale and the Cumulative Illness Rating Scale (CIRS). Living situation was grouped as: (1) lives alone, (2) lives with spouse, (3) lives with child, relative or other and (4) lives in a nursing home. A general linear model univariate analysis was used to compare patients by their respective living situations for differences in mean scores on each of the 4 measures of dementia severity.

RESULTS

Statistical analysis of both unadjusted data and data adjusted for age, sex and CIRS scores showed significant differences among the groups. Those who lived alone were diagnosed at an earlier stage (mean scores: MMSE 21.4, GDS 3.6, FRS 20.0, DAD 29.8) followed by those who lived with a spouse (mean scores: MMSE 20.5, GDS 3.7, FRS 20.4, DAD 28.0), those who lived with a child or other (mean scores: MMSE 19.3, GDS 3.9, FRS 22.5, DAD 24.9) and finally those who lived in a nursing home (mean scores: MMSE 15.2, GDS 4.8, FRS 27.5, DAD 16.9).

CONCLUSION

Living situation is related to the severity of dementia at diagnosis. Primary care providers should have a low threshold for case-finding in older adults who live with family or friends.

Office management of elderly hypertensive patients. Focusing on cognition and function

OBJECTIVE

To review office management of elderly hypertensive patients and to focus on cognition and function both as ways to stratify who gets treated and as end points for treatment.

QUALITY OF EVIDENCE

Relevant papers were identified through a MEDLINE search from January 1994 to March 2000, using the MeSH terms hypertension, aged, aged 80 and over, cognition, activities of daily living, therapeutics, hypotension orthostatic, and dementia. Many well conducted randomized controlled trials were found and are included.

MAIN MESSAGE

Treatment of combined and systolic hypertension up to age 80 is clearly worthwhile; beyond age 85, other factors (chiefly cognitive and functional impairment) mitigate most routine recommendations. Successful treatment is individualized, taking into account comorbid conditions and their effect on cognition and function. Age is useful for thinking about groups, not individuals: as people age, risk of cognitive and functional impairment increases, but even very elderly people (> 85 years) with no impairment should be treated as younger patients are. Elderly people with signs of having a "brain at risk" should be managed with special vigilance.

CONCLUSION

Good evidence supports treating elderly people, who are otherwise well and are cognitively and functionally intact, when their blood pressure is > 160 mm Hg systolic or > 105 mm Hg diastolic. There is insufficient evidence for carrying out routine recommendations for frail elderly people. Treatment of comorbid illnesses dictates choice of therapeutic agent.

Butyrylcholinesterase and cognitive function

Butyrylcholinesterase (BuChE) is expressed in brain structures involved in cognition, but the effect of selective BuChE inhibitors on human cognitive function is unknown. We report a patient whose cognitive function deteriorated following a reduction and improved following reinstitution of ethopropazine, a selective BuChE inhibitor. We suggest that, because neurons expressing BuChE may be involved in cognition, there is merit to further evaluation of selective BuChE inhibitors in treating cognitive dysfunction.

Effects of a flexible galantamine dose in Alzheimer's disease: a randomised, controlled trial

OBJECTIVE

To assess the efficacy and safety of galantamine in Alzheimer's disease at 3 months using flexible dose escalation.

METHODS

A randomised, double blind, placebo controlled trial in 43 centres in the United States, Canada, Great Britain, South Africa, Australia, and New Zealand. Patients with probable Alzheimer's disease (n=386; 171 women) with a score of 11-24 on the mini mental state examination, and a score> or =12 on the cognitive subscale of the Alzheimer's disease assessment scale (ADAS-cog) were randomised to placebo, or galantamine escalated over 4 weeks to a maintenance dose of 24 or 32 mg/day. The primary outcome measures were the change in ADAS-cog score and the clinician's interview based impression of change plus caregiver input (CIBIC-plus) score. Activities of daily living (ADL) and behavioural symptoms were secondary outcomes. To compare the effects of highest levels of dosing, an observed cases (OC) analysis was undertaken, with classic intention to treat (ITT) and ITT with last observation carried forward (LOCF) as confirmatory analyses.

RESULTS

At 3 months, galantamine (24-32 mg/day) produced a significantly better outcome on cognitive function than placebo (treatment difference=1.9 points on ADAS-cog, p=0.002) and a significantly better global response than placebo, as measured by CIBIC-plus (deterioration in 21% of patients on galantamine v 37% on placebo; p<0.001). Galantamine produced significant benefits on basic and instrumental ADL. Behavioural symptoms did not change significantly from baseline levels in either group. Adverse events (primarily gastrointestinal) were of mild to moderate intensity. There were no important differences between the OC, ITT, and ITT/LOCF analyses. Most patients (82%) who were maintained on the higher dose of galantamine completed the study.

CONCLUSIONS

Patients on galantamine, compared with those on placebo, experienced benefits in cognitive function and instrumental and basic activities of daily living. Flexible dose escalation of galantamine was well tolerated.

Progression of impairment in patients with vascular cognitive impairment without dementia

Little is known about progression, short of dementia, in vascular cognitive impairment. In the Canadian Study of Health and Aging, 149 participants (79.3 +/- 6.7 years; 61% women) were found to have vascular cognitive impairment, no dementia (CIND). After 5 years, 77 participants (52%) had died and 58 (46%) had developed dementia. Women were at greater risk of dementia (OR 2.1, 1.0 to 4.5). Of 32 participants alive without dementia, cognition had deteriorated in seven and improved in four. Half of those with vascular CIND developed dementia within 5 years, suggesting a target for preventive interventions.

Screening for PS1 mutations in a referral-based series of AD cases: 21 novel mutations

BACKGROUND

Mutations in the presenilin-1 gene (PS1) account for a majority of patients with early-onset familial AD. However, the clinical indications and algorithms for genetic testing in dementia are still evolving.

METHODS

The entire open reading frame of the PS1 gene was sequenced in a series of 414 consecutive patients referred for diagnostic testing, including 372 patients with AD and 42 asymptomatic persons with a strong family history of AD.

RESULTS

Forty-eight independent patients screened had a PS1 mutation including 21 novel mutations. In addition, 3% of subjects (11/413) had a known polymorphism, the Glu318Gly substitution. The majority of the mutations were missense substitutions but there were three insertions and Delta exon 10 mutation. With six exceptions (codons 35, 178, 352, 354, 358, and 365) most of the mutations occurred at residues conserved in the homologous PS2 gene or in PS1 of other species.

CONCLUSIONS

Eleven percent of a referral-based series of patients with AD can be explained by coding sequence mutations in the PS1 gene. The high frequency of PS1 mutations in this study indicates that screening for PS1 mutations in AD is likely to be successful, especially when directed at patients with a positive family history with onset before 60 years (90% of those with PS1 mutations were affected by age 60 years). This will also have significance for the secondary identification of at-risk relatives who might be candidates for future prophylactic therapies for AD.

Accumulation of deficits as a proxy measure of aging

This paper develops a method for appraising health status in elderly people. A frailty index was defined as the proportion of accumulated deficits (symptoms, signs, functional impairments, and laboratory abnormalities). It serves as an individual state variable, reflecting severity of illness and proximity to death. In a representative database of elderly Canadians we found that deficits accumulated at 3% per year, and show a gamma distribution, typical for systems with redundant components that can be used in case of failure of a given subsystem. Of note, the slope of the index is insensitive to the individual nature of the deficits, and serves as an important prognostic factor for life expectancy. The formula for estimating an individual's life span given the frailty index value is presented. For different patterns of cognitive impairments the average within-group index value increases with the severity of the cognitive impairment, and the relative variability of the index is significantly reduced. Finally, the statistical distribution of the frailty index sharply differs between well groups (gamma distribution) and morbid groups (normal distribution). This pattern reflects an increase in uncompensated deficits in impaired organisms, which would lead to illness of various etiologies, and ultimately to increased mortality. The accumulation of deficits is as an example of a macroscopic variable, i.e., one that reflects general properties of aging at the level of the whole organism rather than any given functional deficiency. In consequence, we propose that it may be used as a proxy measure of aging.

Pharmacotherapy of Alzheimer's disease: is there a need to redefine treatment success?

The traditional aim of Alzheimer's disease treatment in clinical trials has been to improve cognitive abilities. It has become increasingly clear, however, that other aspects are important in assessing treatment responses. A group of 10 physicians recently gathered to review the current criteria for assessing treatment success in Alzheimer's disease. While cognition has been previously viewed as the primary measure of efficacy, areas such as functional abilities, behaviour, caregiver burden, quality of life and resource utilization all need to be comprehensively assessed to fully evaluate treatment effects in patients with Alzheimer's disease, as well as their impacts on caregivers and society. Postponing or slowing decline in any of these areas may represent an important benefit and should be considered as an outcome measure in clinical trials, clinical practice and decision-making about healthcare budgets. Accepted instruments are available for assessing outcomes in each aspect of Alzheimer's disease, but they need to be selected carefully to provide valid, meaningful data. Some of the most frequently used outcome measures in Alzheimer's disease are reviewed. Using expanded criteria for treatment success and clinically relevant outcome measures, data from currently available studies show that cholinesterase inhibitors produce clinically meaningful long-term benefits in multiple domains in patients with Alzheimer's disease.

Assessing the Clinical Importance of Statistically Significant Improvement in Anti-Dementia Drug Trials

A strategy for assessing the clinical importance of statistically significant treatment benefits in recent dementia drug trials is proposed. Traditional criteria for the assessment of valid inferences are helpful: the more likely the treatment effects are valid, the greater the chance that they will be clinically important. The role of the Clinician's Interview-Based Impression of Change is also of some importance. Progress in this area faces the special challenge that the 'new' disease entity of partial treatment of Alzheimer's disease has not been well described. Large, systematic clinical studies of treated patients remain necessary to define reliable guides to successful treatment.

The association between antiulcer medication and initiation of cobalamin replacement in older persons

As chronic use of antiulcer medications might predispose older persons to cobalamin deficiency, we studied participants (> 65 years) in the clinical examination of the Canadian Study of Health and Aging to test the association between the use of an antiulcer medication (histamine-2 blocker or proton pump inhibitor) at baseline with initiation of cobalamin replacement during the 5 year follow-up period. Of 1054 eligible subjects, 125 (11.7%) were taking an antiulcer medication at baseline. At follow-up, 49 (4.6%) had started cobalamin replacement. Antiulcer medication use at baseline was significantly associated with the initiation of cobalamin therapy (odds ratio 2.56, 95% confidence interval 1.30-5.05), even after adjusting for age, gender and institutional residence (odds ratio 2.61, 95% confidence interval 1.31-5.23). There is an independent association between the use of antiulcer medication and initiation of cobalamin therapy. While the relationship is not unambiguously causal, this finding underscores the need for judicious prescribing of antiulcer medications for older persons.

Sleep disturbances and mortality: results from the Canadian Study of Health and Aging

OBJECTIVES

To cross-validate, in a secondary analysis, the observation that daytime sleepiness is associated with an increased risk of death.

DESIGN

Prospective cohort study.

SETTING

Canada, a nationally representative sample of people age 65 and older.

PARTICIPANTS

Nine thousand and eight community-dwelling participants in the Canadian Study of Health and Aging.

MEASUREMENTS

EXPOSURES

self-reported sleep disturbances.

OUTCOMES

Cox hazard ratios (HRs) for death.

RESULTS

The unadjusted analysis showed a small increased risk of death from daytime sleepiness (HR = 1.89; 95% confidence interval (CI) = 1.44-2.46), but this finding did not persist in a multivariate model adjusted for age, depression, cognition, comorbid illness, and function.

CONCLUSION

Daytime sleepiness itself is not associated with an increased risk of death when other factors are taken into account. Daytime sleepiness may be a proxy for other morbid conditions and therefore for overall tiredness.

A reevaluation of the duration of survival after the onset of dementia

BACKGROUND

Dementia shortens life expectancy; estimates of median survival after the onset of dementia have ranged from 5 to 9.3 years. Previous studies of people with existing dementia, however, may have underestimated the deleterious effects of dementia on survival by failing to consider persons with rapidly progressive illness who died before they could be included in a study (referred to as length bias).

METHODS

We used data from the Canadian Study of Health and Aging to estimate survival from the onset of symptoms of dementia; the estimate was adjusted for length bias. A random sample of 10,263 subjects 65 years old or older from throughout Canada was screened for cognitive impairment. For those with dementia, we ascertained the date of onset and conducted follow-up for five years.

RESULTS

We analyzed data on 821 subjects, of whom 396 had probable Alzheimer's disease, 252 had possible Alzheimer's disease, and 173 had vascular dementia. For the group as a whole, the unadjusted median survival was 6.6 years (95 percent confidence interval, 6.2 to 7.1). After adjustment for length bias, the estimated median survival was 3.3 years (95 percent confidence interval, 2.7 to 4.0). The median survival was 3.1 years for subjects with probable Alzheimer's disease, 3.5 years for subjects with possible Alzheimer's disease, and 3.3 years for subjects with vascular dementia.

CONCLUSIONS

Median survival after the onset of dementia is much shorter than has previously been estimated.

Physical activity and risk of cognitive impairment and dementia in elderly persons

CONTEXT

Dementia is common, costly, and highly age related. Little attention has been paid to the identification of modifiable lifestyle habits for its prevention.

OBJECTIVE

To explore the association between physical activity and the risk of cognitive impairment and dementia.

DESIGN, SETTING, AND SUBJECTS

Data come from a community sample of 9008 randomly selected men and women 65 years or older, who were evaluated in the 1991-1992 Canadian Study of Health and Aging, a prospective cohort study of dementia. Of the 6434 eligible subjects who were cognitively normal at baseline, 4615 completed a 5-year follow-up. Screening and clinical evaluations were done at both waves of the study. In 1996-1997, 3894 remained without cognitive impairment, 436 were diagnosed as having cognitive impairment-no dementia, and 285 were diagnosed as having dementia.

MAIN OUTCOME MEASURE

Incident cognitive impairment and dementia by levels of physical activity at baseline.

RESULTS

Compared with no exercise, physical activity was associated with lower risks of cognitive impairment, Alzheimer disease, and dementia of any type. Significant trends for increased protection with greater physical activity were observed. High levels of physical activity were associated with reduced risks of cognitive impairment (age-, sex-, and education-adjusted odds ratio, 0.58; 95% confidence interval, 0.41-0.83), Alzheimer disease (odds ratio, 0.50; 95% confidence interval, 0.28-0.90), and dementia of any type (odds ratio, 0.63; 95% confidence interval, 0.40-0.98).

CONCLUSION

Regular physical activity could represent an important and potent protective factor for cognitive decline and dementia in elderly persons.

Rasch analysis of the hierarchical assessment of balance and mobility (HABAM)

Measuring changes in mobility and balance offers a means of responding to the clinically important challenge of tracking progression and recovery in frail elderly patients who become ill. This article uses Rasch analysis to construct an interval scale from ordinal observations of such changes, using the Hierarchical Assessment of Balance and Mobility (HABAM) on 204 frail elderly inpatients. Principal components analysis confirmed the unidimensionality of the scale. The Rasch analysis confirmed the hierarchy of the HABAM, and pointed to gaps and redundant items. On this basis, an improved version of the HABAM was developed, suitable in its graphical form for everyday clinical use and for research, using the interval numbers that were generated.

Conceptualisation and measurement of frailty in elderly people

The use of the term 'frailty' has shown tremendous growth in the last 15 years, but this has not been accompanied by a widely accepted definition, let alone agreed-upon measures. In this paper, we review approaches to the definition and measurement of frailty and discuss the relationship between frailty, aging and disability. Two trends are evident in definitions, which often trade off comprehensiveness for precision: frailty can be seen as being synonymous with a single-system problem or as a multisystem problem. The essential feature of frailty is the notion of risk due to instability (itself suggesting a balance of many factors), and has been only poorly measured to date. Future models of frailty should incorporate more precise operationalisation of the probability of frailty and better explain the relationship between disease, disability and frailty.

Qualitative analysis of the clinician interview-based impression of change (Plus): methodological issues and implications for clinical research

The Clinician Interview-Based Impression of Change, plus carer interview (CIBIC-Plus), is widely used in antidementia drug trials. It comprises Likert scales for disease severity and changes, and written accounts summarizing semistructured interviews evaluating behavior, cognition, and function. Studies using the CIBIC-Plus have focused on the numeric scores to the exclusion of the textual data. Our study explored both sets of data to evaluate whether the CIBIC-Plus written data supported (a) the clinicians' global evaluation of patients' changes during treatment, and (b) the emergence of consistent treatment effects. The global (numeric) scales of change were inconsistently supported by the textual data provided in the CIBIC-Plus. No consistent treatment effects were noted. Methodological problems presently limit the retrospective use of the CIBIC-Plus textual data. Improved standardization of note-taking in the CIBIC-Plus textual data may allow for a better understanding of the typical profiles and clinical importance of changes seen in the course of dementia treatment.

A clinimetric evaluation of specialized geriatric care for rural dwelling, frail older people

OBJECTIVE

To test Comprehensive Geriatric Assessment (CGA) as an adjunct to usual care.

DESIGN

A randomized controlled trial with 3, 6, and 12 months follow-up.

SETTING

Rural communities.

PATIENTS

A total of 182 of 265 frail older patients (52 refused, 2 withdrawn, 27 ineligible, 2 deaths) referred by family practitioners with allocation to intervention (n = 95) or usual care (n = 87).

INTERVENTION

Three-month implementation of CGA recommendations by a Mobile Geriatric Assessment Team (MGAT) with follow-up assessments at 3, 6, and 12 months. Geriatric nurse assessors, blinded to group assignment, performed each assessment.

MAIN OUTCOME MEASURE

Goal Attainment Scaling (GAS).

RESULTS

Baseline characteristics were comparable between groups. At 3 months, the intervention group was more likely to attain their goals (GAS total: chi = 46.4 +/- 5.9; GAS outcome chi = 48.0 +/- 6.6) compared with controls (total: chi = 38.7 +/- 4.1; outcome chi = 40.8 +/- 5.6) (P < .001). Standard assessments of function (Barthel index, instrumental activities of daily living), cognition (Mini-Mental State Examination), and quality of life (modified Spitzer quality of life index) showed no difference over 12 months. No difference in survival (intervention: chi = 320 days, SE = 6; control: chi = 294 days, SE = 6; P = .257) or time to institutionalization (intervention: 340 days, SE = 9; control: 342 days, SE = 8; log rank = 0.661; P = .416) were observed.

CONCLUSIONS

A MGAT can target rural dwelling, frail older persons, perform in-home CGA, and develop an intervention strategy. Although the intervention did not prolong life or delay institutionalization, clinically important benefits were observed.

Responsiveness of outcome measures used in an antidementia drug trial

The responsiveness of outcome measures used in antidementia drug trials has had little formal analysis, but it can be crucial to the interpretation of a medication's effectiveness. The authors report the responsiveness of outcome measures from the Canadian trial of linopirdine, a novel phenylinodolinone, estimated using an effect size statistic. The effect sizes ranged from 0.10-0.26, with the cognitive and functional measures yielding estimates greater than 0.20, a level held to be clinically detectable. All of the standard measures used in this trial, save one, performed better than the global clinical measure. The global clinical measure used in this study may have been too insensitive to detect minimal clinical change.