ABSTRACTOne of the keys to the success of the Canadian Longitudinal Study on Aging (CLSA) will be the leveraging of secondary data sources, particularly health care utilization (HCU) data. To examine the practical, methodological, and ethical aspects of accessing HCU data, one-on-one qualitative interviews were conducted with 53 data stewards and privacy commissioners/ombudsmen from across Canada. Study participants indicated that obtaining permission to access HCU data is generally possible; however, they noted that this will be a complex and lengthy process requiring considerable and meticulous preparatory work to ensure proper documentation and compliance with jurisdictional variations along legislative and policy lines.
ABSTRACTStandard clinical diagnostic procedures are often inappropriate and frequently not feasible to apply in population-based studies, yet ascertaining accurate disease status is essential. We conducted a systematic review to identify algorithms, criteria, and tools used to ascertain 17 chronic diseases, and assessed the feasibility of developing algorithms for the CLSA. Of the 29,616 citations screened, 668 papers met all inclusion criteria. We determined that the information included in a disease algorithm will differ by condition type. The diagnosis of some symptomatic conditions, such as osteoarthritis and arthritis, will require substantiation by clinical criteria (e.g., x-rays, bone density measurement) while other conditions, such as depression, will rely solely on self-report. Asymptomatic conditions, such as hypertension, are more difficult to ascertain by self-report and will require additional physiologic measures (e.g., blood pressure) as well as laboratory measures (e.g., glucose). This pilot study identified the tools necessary to develop disease ascertainment algorithms.
To determine the dose-response relationship between body mass index (BMI) and cause-specific mortality among Canadian adults.
The sample includes 10,522 adults 18-74 years of age who participated in the Canadian Heart Health Surveys (1986-1995). Participants were divided into 5 BMI categories ( or = 35 kg/m2). Multivariate-adjusted (age, sex, exam year, smoking status, alcohol consumption and education) hazard ratios for all-cause, cardiovascular disease (CVD) and cancer mortality were estimated using Cox proportional hazards regression.
There were 1,149 deaths (402 CVD; 412 cancer) over an average of 13.9 years (range 0.5 to 19.1 years), and the analyses are based on 145,865 person-years. The hazard ratios (95% CI) across successive BMI categories for all-cause mortality were 1.25 (0.83-1.90), 1.00 (reference), 1.06 (0.92-1.22), 1.27 (1.07-1.51) and 1.65 (1.29-2.10). The corresponding hazard ratios for CVD mortality were 1.30 (0.60-2.83), 1.00 (reference), 1.57 (1.22-2.01), 1.72 (1.27-2.33) and 2.09 (1.35-3.22); and for cancer, the hazard ratios were 1.02 (0.48-2.21), 1.00 (reference), 1.14 (0.90-1.44), 1.34 (1.01-1.78) and 1.82 (1.22-2.71). There were significant linear trends across BMI categories for all-cause (p = 0.0001), CVD (p
ABSTRACTThe goal of the Canadian Longitudinal Study on Aging (CLSA) is to recruit 50,000 participants aged 45 to 85 years of age and follow them for at least 20 years. The sampling and recruitment processes for a study of this scope and magnitude present important challenges. Statistics Canada was approached to collaborate with the CLSA with the goal of determining whether the Canadian Community Health Survey (CCHS) could be used as a recruitment vehicle for the CLSA. In this pilot study conducted in 2004, it was determined that 63.8 per cent and 75.8 per cent of the respondents agreed to share their contact information and their survey responses with the CLSA, respectively. The most commonly reported concerns were confidentiality/privacy issues, lack of interest, and commitment issues. This pilot study identified some challenges to the use of the CCHS as a recruitment vehicle for the CLSA.
ABSTRACTCanadians are living longer, and older persons are making up a larger share of the population (14% in 2006, projected to rise to 20% by 2021). The Canadian Longitudinal Study on Aging (CLSA) is a national longitudinal study of adult development and aging that will recruit 50,000 Canadians aged 45 to 85 years of age and follow them for at least 20 years. All participants will provide a common set of information concerning many aspects of health and aging, and 30,000 will undergo an additional in-depth examination coupled with the donation of biological specimens (blood and urine). The CLSA will become a rich data source for the study of the complex interrelationship among the biological, physical, psychosocial, and societal factors that affect healthy aging.
To determine discrepancies between knowledge and practice of childhood motor vehicle restraints (CMVRs) and vehicle seating position amongst parents within the province of Nova Scotia.
Random telephone survey.
The Canadian province of Nova Scotia.
Four hundred and twenty-six households with at least one child under the age of 12 years, totaling 723 children.
The proportion of parents whose children who should be in a specific stage of CMVR and sitting in the rear seat of the vehicle, and who demonstrate correct knowledge of that restraint system and seating position, yet do not use that restraint system/seating position for their child (demonstrate practice discrepant from their knowledge).
Awareness of what restraint system to use is good (>80%). However, knowledge of when it is safe to graduate to the next stage is low (30-55%), most marked for when to use a seatbelt alone. Awareness of the importance of sitting in the rear seat of a vehicle was universal. Discrepancies between knowledge and practice were most marked with booster seats and rear-seating of older children. Factors influencing incorrect practice (prematurely graduated to a higher-level restraint system than what is appropriate for age and weight) included lower household income, caregiver education level, and knowledge of when to graduate from forward-facing car seats and booster seats. Incorrect practice was also more commonly observed amongst children of weight and/or age approaching (but not yet reaching) recommended graduation parameters of the appropriate CMVR.
Discrepancies between knowledge and practice are evident through all stages of CMVRs, but most marked with booster seats. The roles of lower socioeconomic status and gaps in CMVR legislation, in influencing discrepant practice, must be acknowledged and suggest the need for targeted education concurrent with development of comprehensive all-stages CMVR policies.
To investigate whether exercise confounds the relationship between folate and cerebrovascular events, all-cause dementia, and Alzheimer's disease.
Prospective cohort study.
Multiple centers in Canada.
In the Canadian Study of Health and Aging, 466 people reported exercise levels, had folate measurements, and were not demented at baseline. After 5 years, 194 had adverse cerebrovascular events, and 65 had dementia (Alzheimer's disease in 47).
Associations between folate and cerebrovascular outcomes were examined using logistic regression in the presence and absence of exercise and other confounders.
Folate was associated with greater risk of Alzheimer's disease (odds ratio (OR)=2.12, 95% confidence interval (CI)=1.01-4.54) and cerebrovascular outcomes (OR=2.05, 95% CI=1.11-3.78) in adjusted analyses before the inclusion of exercise and neared significance with all-cause dementia (OR=1.80, 95% CI=0.94-3.45). After the inclusion of exercise, the association between folate and dementia and Alzheimer's disease was 29% and 25% lower, respectively, and neither association was any longer significant (Alzheimer's disease: OR=1.91, 95% CI=0.89-4.11; all-cause dementia: OR=1.62, 95% CI=0.84-3.15). Exercise was a significant confounder in the relationship between folate and Alzheimer's disease (P=.03) and dementia (P=.003) but not cerebrovascular outcomes (P=.64). Unlike folate, exercise was significantly associated with Alzheimer's disease (OR=0.43, 95% CI=0.19-0.98) and dementia (OR=0.35, 95% CI=0.17-0.72) in adjusted analyses.
Exercise seems to account for much of the relationship between folate and incident dementia and Alzheimer's disease.
ABSTRACTSuccessful recruitment and retention for population-based longitudinal studies requires understanding facilitators and barriers to participation. This study explored Canadians' views regarding one such study, the proposed Canadian Longitudinal Study on Aging (CLSA). Focus groups of participants > or =40 years of age were held in six proposed CLSA data collection sites (Halifax, Montreal, Hamilton, Winnipeg, Calgary, and Vancouver) to discuss participating in a long-term study of healthy aging. There was fundamental support for longitudinal research on health and aging. Altruism was a key motivation to participation, and universities were viewed as credible parties to conduct such studies. Participants had few worries about providing biological samples but expressed concern about potential misuse of genetic materials, commercialization of participant data, and privacy issues. These findings have already informed current, and will inform future, work on the CLSA, and will also provide useful information to researchers who undertake other population-based longitudinal studies.
ABSTRACTBiological specimen collection is an integral part of many longitudinal epidemiological studies. It is important to achieve high participant satisfaction for continuing involvement, and high sample quality for accurate biomarker measurement. We conducted a study to evaluate these issues on the sample collection proposed for the Canadian Longitudinal Study on Aging (CLSA). There were 85 participants recruited, and 65 attended either a hospital laboratory or private laboratory. Approximately 100 mL of blood and a random urine specimen were collected from each participant for a total of 2,108 sample aliquots. Quality standards were met for more than 90 per cent of samples and were similar for samples collected in both laboratories. More than 90 per cent of participants rated satisfaction with the collection as being good or excellent, and 84 per cent would be willing to repeat the collection in one to three years.
even older adults who are fit experience adverse health outcomes; understanding their risks for adverse outcomes may offer insight into ambient population health. Here, we evaluated mortality risk in relation to social vulnerability among the fittest older adults in a representative community-dwelling sample of older Canadians.
in this secondary analysis of the Canadian Study of Health and Aging, participants (n = 5,703) were aged 70+ years at baseline. A frailty index was used to grade relative levels of fitness/frailty, using 31 self-reported health deficits. The analysis was limited to the fittest people (those reporting 0-1 health deficit). Social vulnerability was trichotomised from a social vulnerability scale, which consisted of 40 self-reported social deficits.
five hundred and eighty-four individuals had 0-1 health deficit. Among them, absolute mortality risk rose with increasing social vulnerability. In those with the lowest level of social vulnerability, 5-year mortality was 10.8%, compared with 32.5% for those with the highest social vulnerability (adjusted hazard ratio 2.5, 95% CI: 1.5-4.3, P = 0.001).
a 22% absolute mortality difference in the fittest older adults is of considerable clinical and public health importance. Routine assessment of social vulnerability by clinicians could have value in predicting the risk of adverse health outcomes in older adults.