Joint effect of stroke and APOE 4 on dementia risk: the Canadian Study of Health and Aging.

BACKGROUND: Although stroke and APOE 4 are independent risk factors for dementia, their combined effect remains uncertain. We assessed their joint effect on dementia risk. METHODS: Subjects participated in Phases 1 and 2 of the Canadian Study of Health and Aging (CSHA). Dementia was diagnosed by consensus, and stroke was diagnosed by history or clinical examination. Analyses were first conducted among clinical participants only, and then rerun with the screening sample included as well. RESULTS: Analyses included 949 participants from CSHA-1 and 1,413 from CSHA-2. During a median 4.6-year follow-up, 740 were included in the CSHA-1 to -2 incidence study. Among clinical participants, the highest prevalence (40.6% for CSHA-1 and 57.6% for CSHA-2) and incidence (8.4 per 100 person-years) of dementia occurred in elderly having both stroke and APOE 4; the lowest prevalence (19.8% for CSHA-1 and 23.3% for CSHA-2) and incidence (4.3 per 100 person-years) were among persons having neither. These findings held true when the screening sample was included. The adjusted hazard ratios of incident dementia, relative to elderly with neither stroke nor APOE 4, were 1.33 (95% CI 0.73 to 2.43) for stroke alone, 2.06 (95% CI 1.42 to 2.99) for APOE 4 alone, and 2.57 (95% CI 1.11 to 5.94) for both. No interaction on additive or multiplicative scales was suggested. CONCLUSIONS: The joint presence of stroke and APOE 4 was associated with a greater risk of dementia compared with absence of these two factors. The effect of stroke on dementia does not seem to be modified by APOE 4.

Effectiveness of case-based on-line learning of evidence-based practice guidelines.

BACKGROUND: Traditional continuing medical education (CME) has not been successful in improving physicians'practice. This project evaluated the use of e-mail to deliver evidence-based moderated case discussions to family physicians. METHODS: In a randomized controlled trial, 58 southwestern Ontario physicians were recruited and randomly assigned to receive two evidence-based cases (type 2 diabetes, prevention) or were put on a waiting list to receive the same. On-line discussions took place about each case. Data were collected using two knowledge questionnaires, charts audits, and standardized patient visits for each of the two cases. RESULTS: The two groups were similar except for rural/urban and solo versus group practice. The latter was related to outcomes, and analyses were controlled for this variable. The intervention group showed statistically significant improvements compared to the control group for knowledge and chart-audit scores for one of the two cases. CONCLUSIONS: Using a randomized control design, this e-mail CME method demonstrated mixed effectiveness.

Preventive health information on the Internet. Qualitative study of consumers' perspectives.

OBJECTIVE: To explore how best to make high-quality preventive health information available to consumers on the Internet. DESIGN: Focus groups. SETTING: Three urban workplaces and one local hospital with patients from a rural family medical practice. PARTICIPANTS: Twenty-two men and 17 women patients. METHOD: Qualitative survey of four focus groups, analysis of transcripts and researchers' notes. MAIN FINDINGS: Five themes characterized participants' perceptions of a consumer website of evidence-based preventive guidelines: content expectations, website design, trustworthiness of content, marketing, and the implications of consumer health information on the Internet. CONCLUSION: Consumers want preventive health information both for taking care of themselves and for participating in a more informed way in their health care when they see a physician. Findings of this study reveal some ways in which consumers' use of Internet health information can affect physicians' and other health professionals' work.

Evidence-based preventive practice guidelines. Qualitative study of useful resources on the Internet.

OBJECTIVE: To explore family physicians' perspectives on how best to provide evidence-based preventive clinical practice guidelines (CPGs) to physicians on the Internet. DESIGN: Focus groups. SETTING: A large, urban centre and a rural community hospital. PARTICIPANTS: Thirty-four of more than 150 family physicians who subscribed to an e-mail discussion group. METHOD: Qualitative survey of four focus groups, analysis of transcripts and researchers' notes. MAIN FINDINGS: Four themes characterized participants' preferences for disseminating preventive CPGs on the Internet: content expectations; quick, easy access to information; trustworthiness of information; and implications for clinical practice. CONCLUSION: Physicians want quick, easy access to trustworthy information. A website for preventive CPGs with these characteristics would be a useful resource.

Chemoprevention of breast cancer. A joint guideline from the Canadian Task Force on Preventive Health Care and the Canadian Breast Cancer Initiative's Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer.

OBJECTIVE: To assist women and their physicians in making decisions regarding the prevention of breast cancer with tamoxifen and raloxifene. EVIDENCE: Systematic review of English-language literature published from 1966 to August 2000 retrieved from MEDLINE, HealthSTAR, Current Contents and Cochrane Library. VALUES: The strength of evidence was evaluated using the methods of the Canadian Task Force on Preventive Health Care and the Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer. RECOMMENDATIONS: Women at low or normal risk of breast cancer (Gail risk assessment index < 1.66% at 5 years): There is fair evidence to recommend against the use of tamoxifen to reduce the risk of breast cancer in women at low or normal risk of the disease (grade D recommendation). Women at higher risk of breast cancer (Gail index > or = 1.66% at 5 years): Evidence supports counselling women at high risk on the potential benefits and harms of breast cancer prevention with tamoxifen (grade B recommendation). The cutoff for defining high risk is arbitrary, but the National Surgical Adjuvant Breast and Bowel Project P-1 Study included women with a 5-year projected risk of at least 1.66% according to the Gail index, and the average risk of patients entered in the trial was 3.2%. Examples of high-risk clinical situations are 2 first-degree relatives with breast cancer, a history of lobular carcinoma in situ or a history of atypical hyperplasia. As the risk of breast cancer increases above 5% and the benefits outweigh the harms, a woman may choose to take tamoxifen. The duration of tamoxifen use in such situations is 5 years based on the results from trials of tamoxifen involving women with early breast cancer. If a woman raises concerns or has already been evaluated and is calculated to be at high risk, then individuals experienced and skilled in counselling may discuss the potential benefits and harms of tamoxifen use. Important additional issues: Prevention of breast cancer with raloxifene: Current evidence does not support recommending chemoprevention of breast cancer with raloxifene outside of a clinical trial setting. Screening using the Gail risk assessment index: This index was the main eligibility criterion for enrolling women in the one study that showed potential benefit from chemoprevention. However, it has not been evaluated for use as a routine screening or case-finding instrument; validation of the index is required. Overall, current evidence does not support a shift to its routine use in physicians' offices for screening or case finding. However, when a woman or her physician is concerned about the woman's increased risk of breast cancer, the index can be a useful tool in deciding whether to pursue an in-depth discussion of the potential benefits and harms of chemoprevention. Hence, the approach to identifying women at higher risk who warrant counselling and shared decision-making will vary across practices. (The risk assessment index is available online at http://bcra.nci.nih.gov/brc/). [A patient version of these guidelines appears in Appendix 2.] VALIDATION: The authors' original text was revised by both the Canadian Task Force on Preventive Health Care and the Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer. The final document reflects a consensus of these contributors. SPONSOR: Health Canada. COMPLETION DATE: February 2001.

The use of medications for cognitive enhancement.

OBJECTIVE: To provide Canadian physicians and allied health care professionals with the evidence they need to help them make treatment decisions in the management of patients with Alzheimer's disease or other dementias. OPTIONS: The full range and quality of diagnostic and therapeutic modalities available to Canadian physicians for the management of dementia. OUTCOMES: Improvement in the treatment of dementias, leading to reduced suffering, increased functional capacity and decreased economic burden. EVIDENCE AND VALUES: The creation of these evidence-based consensus statements involved literature reviews of the subject by the authors; comparison of alternative clinical pathways and description of the methods whereby published data were analyzed; definition of the level of evidence for data in each case; evaluation and revision in a conference setting (involving primary care physicians, neurologists, psychiatrists, geriatricians, psychologists, consumers and other interested parties); insertion of tables showing key variables and data from various studies and tables of data with recommendations; and reassessment by all authors. BENEFITS, HARMS, AND COSTS: A rational plan for the therapy of dementias is likely to lead to substantial benefits in both human and economic terms. RECOMMENDATIONS: Treatment decisions should be made taking into account the severity or stage of the disease, the availability of caregivers, the presence of disease affecting other bodily systems and the ability of the subject to pay the cost of the medications. Donepezil is considered to have positive effects upon certain tests of neuropsychological function and may produce some improvement in Alzheimer's disease of mild to moderate severity as measured by rating scales. Its ability to improve quality of life remains uncertain. No other drug treatments (apart from symptomatic therapies) are at present approved for the treatment of Alzheimer's disease*. VALIDATION: These recommendations were created by a writing committee, evaluated and revised at a consensus conference and further reviewed and revised by the writing committee prior to publication.

The recognition, assessment and management of dementing disorders: conclusions from the Canadian Consensus Conference on Dementia.

OBJECTIVE: i) To develop evidence based consensus statements on which to build clinical practice guidelines for primary care physicians towards the recognition, assessment and management of dementing disorders; ii) to disseminate and evaluate the impact of these statements and guidelines built on these statements. OPTIONS: Structured approach to assessment, including recommended laboratory tests, choices for neuroimaging and referral; management of complications (especially behaviour problems and depression) and use of cognitive enhancing agents. POTENTIAL OUTCOMES: Consistent and improved clinical care of persons with dementia; cost containment by more selective use of laboratory investigations, neuroimaging and referrals; appropriate use of cognitive enhancing agents. EVIDENCE: Authors of each background paper were entrusted to: perform a literature search, discover additional relevant material including references cited in retrieved articles; consult with other experts in the field and then synthesize information. Standard rules of evidence were applied. Based upon this evidence, consensus statements were developed by a group of experts, guided by a steering committee of eight individuals from the areas of Neurology, Geriatric Medicine, Psychiatry, Family Medicine, Preventive Health Care and Health Care Systems. VALUES: Recommendations have been developed with particular attention to the context of primary care and are intended to support family physicians in their ongoing assessment and care of patients with dementia. BENEFITS, HARMS AND COSTS: Potential for improved clinical care of individuals with dementia. A dissemination and evaluation strategy will attempt to measure the impact of the recommendations. RECOMMENDATIONS: See text. VALIDATION: Four other sets of consensus statements and/or guidelines have been published recently. These recommendations are generally congruent with our own consensus statements. The consensus statements have been endorsed by relevant bodies in Canada.

Preventing dementia.

Primary prevention will become increasingly important as dementia prevalence increases and effective retardive therapies are developed. To date, only one randomized controlled trial (involving treatment of systolic hypertension) has demonstrated that the incidence of dementia can be reduced. Physicians should remain alert to possible secondary causes of dementia and correct these whenever possible. Primary and secondary prevention of stroke should reduce dementia related to cerebrovascular disease either directly or as a comorbid factor in Alzheimer's disease (AD). Epidemiological studies have revealed a number of risk factors for AD including genetic mutation, susceptibility genes, positive family history, Down's syndrome, age, sex, years of education, head trauma and neurotoxins. In case-control studies non-steroidal anti-inflammatory medication and estrogen replacement therapy appear to decrease the relative risk of developing AD. Further research to develop and test preventative therapies in AD and other dementias should be strongly encouraged.

The recognition, assessment and management of dementing disorders: conclusions from the Canadian Consensus Conference on Dementia.

OBJECTIVE: To develop evidence based consensus statements on which to build clinical practice guidelines for primary care physicians toward the recognition, assessment and management of dementing disorders and to disseminate and evaluate the impact of these statements and guidelines built on these statements. OPTIONS: Structured approach to assessment, including recommended laboratory tests, choices for neuroimaging and referral, management of complications (especially behavioural problems and depression) and use of cognitive enhancing agents. POTENTIAL OUTCOMES: Consistent and improved clinical care of persons with dementia; cost containment by more selective use of laboratory investigations; neuroimaging and referrals; and appropriate use of cognitive enhancing agents. EVIDENCE: Authors of each background paper were entrusted to perform a literature search, discover additional relevant material, including references cited in retrieved articles, consult with other experts in the field and then synthesize information. Standard rules of evidence were applied. Based on this evidence, consensus statements were developed by a group of experts, guided by a steering committee of 8 individuals, from the areas of Neurology, Geriatric Medicine, Psychiatry, Family Medicine, Preventive Health Care and Health Care Systems. VALUES: Recommendations have been developed with particular attention to the context of primary care, and are intended to support family physicians in their ongoing assessment and care of patients with dementia. BENEFITS HARM AND COSTS: Potential for improved clinical care of people with dementia. A dissemination and evaluation strategy will attempt to measure the impact of the recommendations. RECOMMENDATIONS: Forty-eight recommendations are offered that address the following aspects of dementia care: early recognition; importance of careful history and examination in making a positive diagnosis; essential laboratory tests; rules for neuroimaging and referral; disclosure of diagnosis; importance of monitoring and providing support to caregivers; cultural aspects; detection and treatment of depression; observation and management of behavioural disturbances; detection and reporting of unsafe motor vehicle driving; genetic factors and opportunities for preventing dementia; pharmacological treatment with particular emphasis on cognitive enhancing agents. VALIDATION: Four other sets of consensus statement or guidelines have been published recently. These recommendations are generally congruent with our own consensus statements. The consensus statements have been endorsed by relevant bodies in Canada.

Periodic health examination, 1999 update: 1. Detection, prevention and treatment of obesity. Canadian Task Force on Preventive Health Care.

OBJECTIVES: (1) To evaluate the evidence relating to the effectiveness of methods to prevent and treat obesity, and (2) to provide recommendations for the prevention and treatment of obesity in adults aged 18 to 65 years and for the measurement of the body mass index (BMI) as part of a periodic health examination. OPTIONS: In adults with obesity (BMI greater than 27) management options include weight reduction, prevention of further weight gain or no intervention. OUTCOMES: The long-term (more than 2 years) effectiveness of (a) methods to prevent obesity and (b) methods to treat obesity. EVIDENCE: MEDLINE was searched for articles published from 1966 to April 1998 that related to the prevention and treatment of obesity; additional articles were identified from the bibliographies of review articles and the listings of Current Contents. Selection criteria were used to limit the analysis to prospective studies with at least 2 years' follow-up. BENEFITS, HARM AND COSTS: Health benefits of weight reduction were evaluated in terms of alleviation of symptoms, improved management of obesity-related diseases and a reduction in major clinical outcomes. The health risk of weight-reduction methods were briefly evaluated in terms of increased mortality and morbidity. VALUES: The recommendations of this report reflect the commitment of the Canadian Task Force on Preventive Health Care to provide a structured, evidence-based appraisal of whether a manoeuvre should be part of a periodic health examination. RECOMMENDATIONS: (1) PREVENTION: There is insufficient evidence to recommend in favour of or against community-based obesity prevention programs; however, because of considerable health risks associated with obesity and the limited long-term effectiveness of weight-reduction methods, the prevention of obesity should be a high priority for health care providers (grade C recommendation). (2) TREATMENT: (a) For obese adults without obesity-related diseases, there is insufficient evidence to recommend in favour of or against weight-reduction therapy because of a lack of evidence supporting the long-term effectiveness of weight-reduction methods (grade C recommendation); (b) for obese adults with obesity-related diseases (e.g., diabetes mellitus, hypertension), weight reduction is recommended because it can alleviate symptoms and reduce drug therapy requirements, at least in the short term (grade B recommendation). (3) Detection: (a) for people without obesity-related diseases, there is insufficient evidence to recommend the inclusion or exclusion of BMI measurement as part of a periodic health examination, and therefore BMI measurement is left to the discretion of individual health care providers (grade C recommendation); (b) for people with obesity-related diseases, BMI measurement is recommended because weight reduction should be considered with a BMI of more than 27 (grade B recommendation). VALIDATION: The findings of this analysis were reviewed through an iterative process by the members of the Canadian Task Force on Preventive Health Care. SPONSORS: The Canadian Task Force on Preventive Health Care is funded through a partnership between the Provincial and Territorial Ministries of Health and Health Canada.

Risk of a new benzodiazepine prescription in relation to recent hospitalization.

OBJECTIVE: To determine if recent hospital admission was associated with new outpatient prescribing of benzodiazepines among community-dwelling older people. DESIGN: Nested case-control study using administrative data sets of the provincial health insurance board. SETTING: Province of Quebec. PARTICIPANTS: Cases were 4127 community-dwelling older people who were newly dispensed a benzodiazepine during an 8-month period in 1990. Controls were 16,486 community-dwelling older people who were dispensed any drug (except a benzodiazepine) on the same day as the case-defining index prescription. EXPOSURE AND OUTCOME MEASURES: Admission to an acute care hospital within a 30-day period before a new dispensing of a benzodiazepine. Other variables measured were patient age, gender, number of ambulatory physician visits, healthcare region, Chronic Disease Score (CDS), and use of drugs for depression and psychosis. RESULTS: Cases were more than three times as likely as controls to have been hospitalized in the 30-day period before the index date (adjusted odds ratio (OR) 3.09; 95% CI, 2.78-3.45). The use of prescription drugs for physical health problems modified this association in that cases who used more medication were also more likely to receive a new benzodiazepine prescription following a recent hospital admission (adjusted OR 4.09; 95% CI, 3.59-4.65 when the CDS was equal to 5 vs adjusted OR 1.96; 95% CI, 1.66-2.31 when the CDS was equal to 0). CONCLUSIONS: Recent hospitalization confers an increased risk of a new outpatient benzodiazepine prescription among community-dwelling older people in Quebec. Those who use more medication, and who may be more vulnerable to drug-related adverse events, are more likely to be newly dispensed a benzodiazepine following a recent, acute-care hospital admission.

Patients' desires and expectations for medical care in primary care clinics.

To explore whether patients' desires for and expectations of medical care differ between the United States and Canada, we surveyed 652 patients and 105 physicians at primary care sites in Michigan and Ontario. Patient desires were similar at both sites, but expectations were higher in Michigan. Michigan physicians gave higher estimates of patient desire than physicians in Ontario. Physicians at both sites, however, similarly underestimated patients' desires. These between-site differences in expectation may reflect differences both in general cultural factors and in patient exposure to different clinical policies within the medical systems.

Promoting the health of senior citizens.

Canada is experiencing a dramatic increase in the number of older people in its population. Adopting strategies that involve physician actions, a societal approach and individual participation may substantially improve the health of senior citizens. This article presents ways to improve the quality of life and reduce the risk of premature death through manoeuvres that can be initiated by physicians in the context of the periodic health examination. The authors highlight the role of evidence in choosing the most appropriate interventions, speculate on areas of future importance and emphasize a societal approach to population health.

The early detection and treatment of prostate cancer: the perspective of the Canadian Task Force on the Periodic Health Examination.

Few would challenge the important health burden associated with prostate cancer. This concern, combined with the emergence of a biochemical test that has the potential for early detection, has fueled enthusiasm for concerted efforts aimed at early detection and treatment of prostate cancer. Reflecting the approach and perspective of the Canadian Task Force on the Periodic Health Examination, this report argues for the objective evaluation of evidence to address the question of whether to initiate and promote early detection campaigns for prostate cancer. Specifically, 3 questions are addressed: "what is the goal of early detection?", "how should the existing evidence be evaluated?" and "how should evidence guide our actions and policies?". After reviewing the evidence using its standardized rules of evidence, the Canadian Task Force has concluded that there presently is insufficient evidence to promote the early detection of prostate cancer in asymptomatic men.