Browsing by Author "Oremus, Mark"

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The Association Between Functional Social Support and Memory: A Prospective Analysis of the Canadian Longitudinal Study on Aging
(University of Waterloo, 2021-06-01) Yoo, Samantha Sanghee; Oremus, Mark
Identifying modifiable psychosocial factors that influence age-related outcomes is important for healthy aging. Functional social support (FSS), or the perceived availability of support from others, appears to delay memory loss via biological and psychological pathways. However, due to the complexity of measuring FSS, evidence is limited regarding its association with memory. Objective of this thesis was to identify an association between FSS and change in memory using baseline and 3-year follow-up data from the Comprehensive Cohort of the Canadian Longitudinal Study on Aging (CLSA), an ongoing cohort study of adults aged 45-85 years at baseline. FSS was measured via the Medical Outcomes Study–Social Support Survey (MOS–SSS); immediate and delayed recall memory were measured with the Rey Auditory Verbal Learning Test I and II, respectively. The RAVLT I and II z-scores were averaged at each time point to compute a combined memory z-score. Multiple linear regression was used for the analysis. The difference between the combined baseline and combined follow-up memory scores was regressed on the FSS variables (overall and four subtypes), which were categorized into high (scores ≥ 4) or low (scores ≤ 3), while controlling for baseline memory scores, sociodemographic variables, health variables, and lifestyle variables. The analytic sample comprised 12,011 participants (mean age = 61 years). The participants reported high levels of FSS (overall FSS: weighted mean = 4.34 out of 5.00 [standard error = 0.01]; weighted median = 4.46 [interquartile range = 0.88]). Fifty-seven percent of the weighted sample reported declines in combined memory scores over three years. Regression models indicated weak yet generally positive associations between overall and subtypes of FSS and positive changes in memory score over three years, although most regression coefficients were not statistically significant (α = 0.05). No clear pattern of effect modification was identified across the age and sex groups in stratified regression models. CLSA participants were cognitively stable and most reported a high level of FSS, which likely contributed to the weak and non-significant associations between FSS and change in memory scores. A substantial attrition of participants with RAVLT measurements may also have contributed to the lack of significant associations. Longer follow-up of the CLSA sample is likely required to further assess this association.
The Association between Religious Participation and Social Isolation in Canadian Middle-and Older-aged Adults: A Longitudinal Analysis of the Canadian Longitudinal Study on Aging
(University of Waterloo, 2022-06-14) Ming, Kirsten; Oremus, Mark
Social isolation is a modifiable risk factor for poor health outcomes, including cognitive decline, cardiovascular disease, and mental illness. Thus, researchers seek to identify exposures that are inversely associated with social isolation itself. Religious participation may be one such exposure because research has shown it to be positively associated with social support and social integration, two concepts related to decreases in social isolation. However, the association between religious participation and social isolation has not been investigated in depth. The objective of this thesis was to examine the association between religious participation and social isolation using baseline and three-year follow-up data from the Comprehensive Cohort of the Canadian Longitudinal Study on Aging (CLSA). The CLSA is an ongoing prospective cohort study of community-dwelling adults who were between 45 and 85 years old at recruitment. Religious participation was measured via a single question, asking participants how often they participated in religious activities over the past 12 months (e.g., services, committees, choirs). Responses were recorded on a 5-point scale ranging from “at least once a day” to “never”, which served as the reference category in regression modeling. Social isolation was measured with an index computed by Menec et al., which tabulated the absence of social interactions, relationships, and a lack of participation in community activities, as well as included retirement status and marital status. Social isolation index scores ranged from 0 to 5 and were dichotomized into “socially isolated” or “not socially isolated”. Multiple logistic regression was used for the analysis. Follow-up social isolation index scores were regressed onto baseline religious participation responses while controlling for baseline social isolation, sociodemographic variables, health variables, and functional social support. The fully adjusted model was stratified by age groups and sex separately. The analytical sample comprised 22,139 participants. Approximately 50% of participants participated in religious activities at least once a year. At baseline, 7% of participants were socially isolated, and 6% were socially isolated at follow-up. Regression models indicated small and inverse associations between religious participation and social isolation over three years; however, none of the results were statistically significant (α = 0.05), thereby suggesting the possibility of positive associations. The results did not identify any effect modification by age groups and sex. Most CLSA participants were not socially isolated, which contributed to the non-significant and small associations between religious participation and social isolation. Longer follow-ups of the CLSA sample and a larger proportion of socially isolated individuals are needed to assess this association further.
The Association between Social Isolation and Memory Function in Middle-aged and Older Adults: A Cross-sectional Analysis of the Comprehensive Cohort of the Canadian Longitudinal Study on Aging
(University of Waterloo, 2023-01-20) Taqvi, Urooj; Oremus, Mark
Background: Social isolation is a psychosocial risk factor thought to be inversely associated with memory function, although only a small number of published studies exist in the field. These studies report mixed results due to variations in methods (e.g., study design, measures of social isolation that do not capture the full extent of the construct) or the inclusion of highly select samples of target populations. Given limitations of the published literature, this thesis investigated the cross-sectional association between social isolation and memory in a large, community-dwelling sample of Canadian adults aged between 45 and 85 years. The association was examined across the entire sample and in separate stratified analyses defined by age group and sex. Methods: Baseline data from the Comprehensive Cohort of the Canadian Longitudinal Study on Aging (CLSA) were used to regress memory scores onto a composite Social Isolation Index (SII) that measured numbers of social contacts, frequencies of interaction with these contacts, frequencies of participation in social activities, marital status, and retirement status. The SII ranged from 0–5 and scores between 2-5 were classified as “socially isolated”, while scores between 0-1 were classified as “not socially isolated”. The dichotomous version of the SII was used in all analyses. Memory was measured using the immediate and delayed recall administrations of the Rey Auditory Verbal Learning Test (RAVLT); raw test scores were converted into z-scores (𝜇 = 0, 𝜎 = 1) and analyzed separately for each administration. Multivariable linear regression models controlled for a range of covariates, including age group, sex, education, income, presence of chronic conditions (≥ 1 versus 0), functional impairment, presence of depressive symptoms, smoking status, alcohol use, and functional social support (low versus high). Weight and strata variables were included in the models to account for the CLSA’s complex survey design. Full models adjusted for all covariates (except for those used for stratification purposes) were separately stratified by age group and sex to assess effect modification. Results: Regression models showed small, inverse associations between social isolation and RAVLT I (β = -0.0019; 95% CI: -0.0469 to 0.043) and RAVLT II (β = -0.0010; 95% CI: -0.0496 to 0.0475) z-scores. However, the associations were weak and not statistically significant. Stratification by age group and sex did not show the presence of effect modification. Conclusion: The results did not provide evidence for a cross-sectional association between social isolation and memory in the CLSA sample. These results may indicate the absence of an association in the population of middle-aged and older Canadian adults. The CLSA intentionally excluded cognitively impaired individuals from the study (recruitment bias) and individuals who were not socially isolated appeared to be more likely to participate in the study (volunteer bias). Taken together, these biases may have contributed to the weak and statistically non-significant associations. Longitudinal analyses may be needed to investigate the association between social isolation and memory in the CLSA, as more variability in the sample’s degree of social isolation and memory can be expected as the participants age over time.
The Association between Social Isolation, Functional Social Support, and Memory: A Moderated Mediation Analysis of the Canadian Longitudinal Study on Aging
(University of Waterloo, 2024-06-20) Endresz, Nicole; Oremus, Mark
Social support is a widely investigated, modifiable factor thought to promote memory function and successful aging. However, the intertwined effects of the two components of social support – objective social isolation and subjective functional social support – on memory are less understood. Therefore, we explored whether social isolation was associated with memory function in middle-aged and older adults, and whether this association was mediated by functional social support. We also examined moderated mediation by age group and sex. We analyzed data from the baseline and first follow-up waves of the Tracking Cohort of the Canadian Longitudinal Study on Aging. These data included a derived variable for social isolation, a standardized instrument for self-reported functional social support, and a combined immediate and delayed recall memory score from a modified version of the Rey Auditory Visual Learning Test. Using multiple linear regression and an analytical sample of 12,834, we regressed memory scores at follow-up onto baseline social isolation status, controlling for baseline sociodemographic, health, and lifestyle covariates, baseline memory, and baseline and follow-up functional social support. We further assessed whether functional social support at follow-up mediated the association between baseline social isolation and follow-up memory. To assess moderated mediation, each path of the mediation analysis was stratified by age group and sex The independent and direct effect of social isolation on memory controlling for covariates showed a non-statistically significant, inverse association. Social isolation predicted lower levels of functional social support, whereas high functional social support was associated with higher memory scores. Memory scores decreased on average by 0.03 points in socially isolated participants versus non-isolated participants, when mediated by functional social support. Lastly, some evidence of effect modification was found by the oldest age group on the “a” path of the mediation analysis. This thesis provides novel findings on the mediating effect of functional social support on the relationship between social isolation and memory. Our findings suggest the association between social isolation and memory operates through, not independently of, functional social support. Health professionals working with socially isolated individuals at risk of, or experiencing, memory problems should pay particular attention to these individuals' levels of functional social support.
The Association Between Social Support Availability and Memory: A Cross-Sectional Analysis of the Canadian Longitudinal Study on Aging
(University of Waterloo, 2020-06-18) Ohman, Avery; Oremus, Mark
Population aging leads to a rise in the prevalence of age-related cognitive decline. While some declines in the memory domain of cognitive function are expected as people age, deterioration beyond a certain point may reduce functional ability and independence, and increase the risk of dementia. Therefore, it is critical to gain a better understanding of the protective and risk factors for memory function to promote better health throughout the aging process. Social support is a modifiable psychosocial factor that has been shown to be positively associated with the maintenance of cognitive function. However, little evidence on this topic has been gathered from large-scale, population-based studies that include middle- and older-aged adults, leading to a gap in the understanding of the nature of this association. The objective of this study was to investigate the relationship between social support availability (SSA) and memory function using data from the Comprehensive Cohort of the Canadian Longitudinal Study on Aging (CLSA). This thesis used multiple linear regression to explore the association between SSA (measured using the 19-item Medical Outcomes Study-Social Support Survey) and memory (measured using the immediate and delayed recall Rey Auditory Verbal Learning Test), controlling for covariates including sociodemographic factors, health-related factors, depressive symptoms, and health behaviours. Results show that overall, there is a significant positive association between SSA (overall and subtypes) and memory function, both before and after adjusting for covariates. For sex-stratified analyses, stronger associations were typically observed for males compared to females for both immediate and delayed recall. Mixed findings were observed for age group-stratified results, with the strength of association for each age group varying substantially by SSA subtype and trial of the REY test. This research addresses gaps in the literature, building on existing evidence that there is a link between SSA and memory function. Findings help to improve the understanding of the relationship between SSA and memory, and suggests that there are subgroups of the population that may benefit optimally from SSA, thereby supporting the development of social support initiatives to promote healthy cognitive function in Canadians.
The Effect of Adverse Childhood Experiences on Depression Symptoms among Older Adults in China
(University of Waterloo, 2019-07-24) fang, mingying; Oremus, Mark
Background Depression is not a normal part of aging. However, it is a serious, growing problem for the elderly population of China, where the world’s largest cohort of people aged 60 and over is growing rapidly. Research recognizes that adverse childhood experiences (ACEs), such as being abused or neglected, are important risk factors for depression and other psychological disorders in later life. Relationships between ACEs and risk factors contributing to depression symptoms in older populations, such as socioeconomic situation, health status, and environmental characteristics have also been established in the literature. In the 20th century, China experienced an eight-year war of resistance against Japan, a three-year civil war, political and cultural revolutions, rapid economic development, and rural-urban transitions. These events may have had a long-term impact on the psychological and physical health of the Chinese population, especially for children who were exposed to these events. However, little research has examined the association between ACEs and depression symptoms in today’s older Chinese population, who were children at the time of these transformative events in China’s history. Objectives This dissertation examined the association between several ACEs and depression symptoms among older adults in China, after controlling for covariates at individual and community levels. Examples of these ACEs include death of parents, death of siblings, physical abuse, being bullied, feeling alone, poor relationships with parents/friends/neighbours, and disadvantaged neighbourhood. Methods This dissertation was based on secondary data analysis of the China Health and Retirement Longitudinal Study (CHARLS) wave 1, wave 2, and life history surveys. A score of 10 on the 10-item Center for Epidemiologic Studies Depression Scale (CES-D-10) was used as the cutoff for identifying the presence of meaningful depression symptoms. The associations between ACEs and depression symptoms were assessed using two-level, random-intercept simple and multiple logistic regression models, adjusting for individual- and community-level covariates. More specifically, the covariates were selected using theoretical justifications from the literature and the least absolute shrinkage and selection operator (LASSO) approach. The theoretical framework of this dissertation was based on the social determinants of health framework, life-course approach, and the social-ecological framework. Results This thesis analysis included 1,218 older adults living in 360 communities after listwise deletion of missing values. The mean age of the respondents was 68.2 years, the majority of whom had low education levels, were female, married, living with their spouses, and living in rural areas. 33.4% reported CES-D-10 scores of 10 or higher, with a median of 7 and interquartile range (IQR) of 7 (maximum possible score = 30). Among ACEs, high rates of parental deaths, physical abuse, hunger, and rural residence before the age of 18 were reported among Chinese older adults. Overall, most of the respondents reported good or better childhood health and no health limitations before age 18. The findings suggest some ACEs are associated with a higher prevalence of depression symptoms in older adults in China. The adjusted odds of depression symptoms were higher for older adults who experienced the following ACEs: bullying (OR= 1.45, 95% CI= [1.01, 2.10]), loneliness (OR= 1.58, 95% CI= [1.08, 2.30]), had a poor relationship with their mother (OR= 1.98, 95% CI= [1.09, 3.58]), and had poor health status (OR= 1.54, 95% CI= [1.07, 2.65]). Conclusion Results from this dissertation show that some childhood adversities can impact depression symptoms in older adults.
The Effect of Religious Participation on Cognitive Function in Middle- and Old-Aged Adults: A Sequential Explanatory Mixed Methods Study of the Canadian Longitudinal Study on Aging
(University of Waterloo, 2019-12-05) Hosseini, Sheri; Oremus, Mark
Background: Preserving cognitive health is a crucial aspect of successful aging. Atypical cognitive decline is linked to the onset of dementia disorders such as Alzheimer’s disease. Even normal cognitive deterioration can negatively influence the health of aging populations. Religious involvement has been shown to have a positive impact on cognitive function. However, this association has not been explored in the Canadian population. Methods: This thesis aimed to investigate the association between frequency of religious participation and cognitive function among middle- and older-aged adults. The thesis included two parts forming a sequential-explanatory mixed methods study. The quantitative part of this study was conducted at the population-level and included analyses of baseline data from between 8,047 and 28,701 individuals aged between 45 and 85 years, depending on the analytical sample and regression model, who were recruited as part of the Canadian Longitudinal Study on Aging (CLSA). The quantitative analyses were supplemented and enhanced with a qualitative study involving members of Christian communities, including pastors and parishioners. These individuals mirrored the characteristics of CLSA participants. The intention of undertaking the qualitative component was to augment the quantitative results with pastors’ and parishioners’ interpretations and explanations of these results. Results: The quantitative analyses did not find a substantial number of statistically significant associations between frequency of religious participation and cognitive function, following adjustment for an array of demographic, health related, social, and socioeconomic covariates. Based on the qualitative findings, frequency of religious participation may not be an accurate representation of the wider construct of religious involvement. The qualitative findings suggested that religious involvement, if considered in broader terms than just the act of participation, may be associated with improved mental health, social interaction and support, and an active mind, all of which have positive impacts on cognitive function. Conclusions: Frequency of religious participation did not capture the breadth of religious involvement in the quantitative sample and, as such, few of the findings were statistically significant, and some findings contradicted our hypothesis of a positive association between religious participation and cognitive function. However, religious participation extends beyond simply attending church services. Future research needs to employ a broader range of measures of religious participation to more fully assess the association between religious involvement and cognitive function.
Exploring the association between religiosity, spirituality and cancer screening behavior: a longitudinal analysis of Alberta’s Tomorrow Project
(University of Waterloo, 2020-05-19) Mirabi, Susan; Oremus, Mark
Background: This thesis examined the effect of religiosity/spirituality (R/S) on breast, prostate, and colorectal cancer screening behaviour. Over two-thirds of Canadians identify with some form of religion or spirituality. R/S can affect the intentions, beliefs and behaviours of individuals. Many religious and spiritual practices place an emphasis on the preservation of health. Breast, prostate and colorectal cancers account for a large proportion of cancers in Canada. Screening is an effective form of secondary prevention for cancer. R/S may provide a platform of positive influence to encourage greater cancer screening. Objective: Data from Alberta’s Tomorrow Project (ATP) were used to explore the longitudinal association between R/S and breast, prostate and colorectal cancer screening behaviour. Methods: ATP participants between 35 and 70 years, without a history of chronic disease at baseline, were included in the analysis. For longitudinal analysis, participants had a minimum of one post-baseline screening datapoint. R/S was measured through two variables: Salience and Attendance. R/S Salience assessed the importance of religion or spirituality to ATP participants, asking them: “Do spirituality values or faith play an important role in your life?” Response options for R/S Salience were “Yes” or “No.” R/S Attendance assessed whether participants attended religious or spiritual services, with response options being limited to “Attends” or “Does Not Attend.” Multivariable logistic regression models were built for each R/S and cancer screening variable separately. All models were adjusted for age, social support, income, occupation, education, sex, marital status, perceived health, and smoking status. Results: Due to the large proportion of women undergoing mammography (69% at baseline and 95% at the final follow-up period), breast cancer screening was assessed cross-sectionally. Neither R/S Salience nor R/S Attendance were found to be statistically significantly associated with breast cancer screening (odds ratio [OR]=1.10, 95% confidence interval [CI]: 0.93-1.27, and OR:1.02, 95% CI: 0.86-1.21, respectively). Longitudinal analysis revealed that R/S Salience and R/S Attendance were also not statistically significantly associated with prostate cancer screening (OR:0.90, 95% CI: 0.68-1.19, and OR:1.18, 95% CI: 0.88-1.59, respectively). Only models for R/S and colorectal cancer screening produced statistically significant results. ATP participants who responded “Yes” to R/S Salience (compared to ‘No’), and participants who attended (versus not attended) religious or spiritual services (R/S Attendance), had 1.4 times (95% CI: 1.15-1.73) or 1.5 times (95% CI: 1.12-1.89) greater odds of obtaining a sigmoidoscopy or colonoscopy, respectively. Discussion: This thesis provided a Canadian context for the association between R/S and cancer screening, and added to the literature by incorporating both cross-sectional and longitudinal analyses; the preservation of temporality allowed us to examine whether the effects of R/S persisted over time. The current analyses were conducted using persons drawn from a large, population-based study encompassing a sample of adults aged between 35 and 70 years (n=5,014-11,977). This thesis suggested that R/S may have a positive influence on the cancer screening behaviours of Canadians. Future research should explore whether public health officials can leverage the effects of R/S to help increase the incidence of screening for cancers in populations where screening behaviour remains low.
Exploring the differential impacts of social isolation, loneliness, and their combination on the memory of an aging population: A 6-year longitudinal study of the CLSA
(Elsevier, 2024) Kang, Ji Won; Oremus, Mark; Dubin, Joel; Tyas, Suzanne L; Oga-Omenka, Charity; Golberg, Meira
Memory plays a crucial role in cognitive health. Social isolation (SI) and loneliness (LON) are recognized risk factors for global cognition, although their combined effects on memory have been understudied in the literature. This study used three waves of data over six years from the Canadian Longitudinal Study on Aging to examine whether SI and LON are individually and jointly associated with memory in community-dwelling middle-aged and older adults (n = 14,208). LON was assessed with the question: "In the last week, how often did you feel lonely?". SI was measured using an index based on marital/cohabiting status, retirement status, social activity participation, and social network contacts. Memory was evaluated with combined z-scores from two administrations of the Rey Auditory Verbal Learning Test (immediate-recall, delayed-recall). We conducted our analyses using all available data across the three timepoints and retained participants with missing covariate data. Linear mixed models were used to regress combined memory scores onto SI and LON, adjusting for sociodemographic, health, functional ability, and lifestyle variables. Experiencing both SI and LON had the greatest inverse effect on memory (least-squares mean: -0.80 [95 % confidence-interval: -1.22, -0.39]), followed by LON alone (-0.73 [-1.13, -0.34]), then SI alone (-0.69 [-1.09, -0.29]), and lastly by being neither lonely nor isolated (-0.65 [-1.05, -0.25]). Sensitivity analyses confirmed this hierarchy of effects. Policies developed to enhance memory in middle-aged and older adults might achieve greater benefits when targeting the alleviation of both SI and LON rather than one or the other individually.
The impact of assistive devices on community-dwelling older adults and their informal caregivers
(University of Waterloo, 2023-04-12) Marasinghe, Keshini Madara; Chaurasia, Ashok; Oremus, Mark
Background Canadians are aging and living longer with chronic conditions, multimorbidity, and disabilities, which can have negative impacts on the health and quality of life of both older adults and their informal caregivers. Assistive devices (AD) can be beneficial to community-dwelling older adults and their informal caregivers; however, researchers have not investigated all outcomes of using AD. Two under-investigated outcomes in aging populations are: (a) the change in life satisfaction (LS) over time, and (b) the change in the number of informal caregiving hours received over time. The Consortium for Assistive Technology Outcome Research (CATOR) framework was used to frame the following objectives, which identifies LS and the amount of informal caregiving hours received as key outcomes of AD use. Objectives The objectives of this thesis were addressed via three studies: Study 1 (Chapter 3) examined existing evidence on the associations between (a) AD use and LS, and (b) AD use and informal caregiving hours received; Study 2 (Chapter 4) and Study 3 (Chapter 5) investigated the associations between self-reported AD use within the past 12 months (assessed at baseline) and: (a) the change in LS over time (three-years), (b) the change in informal caregiving hours received over time (three-years), respectively. All studies focused on community-dwelling older adults aged 65 years or older. Methods Study 1 consisted of a systematic review adhering to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Studies 2 and 3 used unweighted data from the Tracking and Comprehensive cohorts of the Canadian Longitudinal Study on Aging (CLSA) and multiple linear regression models to investigate the associations between AD use and the change in LS or informal caregiver time. The regression analyses controlled for comprehensive sets of covariates. Results Study 1 suggested AD use was not linked with LS and was associated with reductions in informal caregiving hours. However, due to the scarcity of existing studies, their limitations (e.g., high risk of bias, residual confounding, cross-sectional nature), and very low or moderate strength of evidence, conclusions about the associations of interest could not be drawn with certainty. Results from Study 2 did not find evidence of an association between AD use and increases in LS over time, after accounting for covariates (Tracking: n = 5,502, β = 1.16, 95% Confidence Interval [CI] = -0.57 to 2.89; Comprehensive: n = 9,760, β = 0.47, 95% CI = -0.89 to 1.82). Similarly, after controlling for covariates, Study 3 did not find associations between AD use and changes in informal caregiving hours received over time (Tracking: n = 236, β = 3.10, 95% CI = -77.98 to 84.17; Comprehensive: n = 420, β = -5.05, 95% CI = -47.19 to 37.09). Conclusion In an aging society, empirical evidence regarding the effects of AD on the changes in LS and informal caregiver hours is imperative for evidence-based decision-making and effective recommendations on the provision of AD to older adults. Although the findings of this thesis were non-significant, null findings can be informative because they can contribute to guiding future studies, informing existing theories, and avoiding misleading research conclusions or biased evidence-based practices and policies. To overcome the limitations of existing studies, future research should aim to extend beyond three years, use large sample sizes, conduct analyses based on the type of AD used (e.g., mobility versus vision-related AD) and the duration of AD use (e.g., short, long, intermittent use), and control for additional potential confounders (e.g., device satisfaction, time-varying confounders). LS questions should be specifically tailored to AD use and informal caregivers should be directly interviewed to promote the accuracy of data on informal caregiving hours. Data sets designed to collect information primarily on AD should be used in future investigations to address the research questions in this thesis. These data sets should ideally be culturally representative and have minimal bias (e.g., selection bias, missing data) to assure reliability and generalizability of the findings. This thesis further highlighted various implications for future research, theory, policy and practice. These implications included the complexity of research questions and concepts (i.e., life satisfaction, accurate capture of informal caregiving hours from care receivers and caregivers), overcoming limitations of existing studies, the importance of stratified analysis to inform sub-theories in the CATOR framework, integration of evidence from multiple sources (e.g., experimental studies), funding for improved research, recognition of null findings, and collaborative efforts among stakeholders to make informed decisions related to AD use among community-dwelling older adults.
Perceived Susceptibility to Developing Cancer and Cancer Screening Behaviour: A Longitudinal Analysis of Alberta’s Tomorrow Project
(University of Waterloo, 2017-10-25) Gilfoyle, Meghan; Oremus, Mark
Background: Screening for cancer is a secondary prevention strategy that relies on early detection of disease. Screening is given to asymptomatic individuals who are at risk of developing cancer to identify and halt the pathological development of disease, reduce treatment invasiveness and improve outcomes. Perceived susceptibility (PS) – whether an individual feels they are personally vulnerable to a health-related condition or disease – has been shown to be associated with cancer screening uptake and past screening behaviour. Overall Objective: We propose to use data from Alberta’s Tomorrow Project (ATP) to address the research questions outlined below. Research Questions: Is PS to developing cancer associated with the incidence of mammography, prostate-specific antigen, sigmoidoscopy, and colonoscopy screening tests? Does an individual’s perceived susceptibility affect screening behaviour differently between tests? Methods: We included ATP participants between the ages of 35 to 70 years who reported being free of chronic conditions at their baseline survey and who had completed at least one follow-up survey. PS was measured using three variables: PS1-5 (measured on a 5-point scale from 1 [low risk] to 5 [high risk]): “Compared to other people your age, what do you think are your chances of being diagnosed with cancer in your lifetime”, PS100gen asked: “On a scale of 0% to 100%, what percentage of people your age in the general population do you think will be diagnosed with cancer in their lifetime?” and PS100my asked: “On a scale from 0% to 100%, on which 0 means you definitely will not be diagnosed with cancer and 100 means you definitely will be diagnosed with cancer, what would you estimate to be your chance of being diagnosed with cancer in your lifetime?”. To examine the association between PS and incident screening over the course of follow-up, we built a series of multivariable logistic regression models for each of the screening tests of interest, and adjusted for covariates such as age, education, family history, and marital status. Results: PS of developing cancer was statistically significantly associated with prostate-specific antigen (PSA) and sigmoidoscopy/colonoscopy screening behaviour over baseline and two waves of follow-up, spanning a total of 14 years, for both personal risk variables (PS1-5 and PS100my). Specifically, the odds of receiving compared to not receiving a PSA test were 1.36 times greater for a one-unit increase in PS1-5 (CI=1.07 – 1.72), and the odds were 1.02 times higher for a one-unit increase in PS100my ranging from 0 to 100 (CI=1.01 – 1.03). Furthermore, the odds of receiving compared to not receiving a sigmoidoscopy/colonoscopy were 1.97 times greater for a one-unit increase in PS1-5 (CI=1.52 – 2.55), and the odds were 1.03 times greater for a one-unit increase in PS100my ranging from 0 to 100 (CI=1.0 – 1.04). Conclusion: Understanding how certain factors, such as PS, are associated with screening behaviour has been an important focus for addressing the underutilization of screening for cancer in Canada. Personal PS of developing cancer is predictive of screening behaviour for PSA and sigmoidoscopy/colonoscopy screening tests over time. These findings provide a basis for public health programming and policies throughout Canada, aimed at promoting screening behaviour. Future studies should explore additional factors, as outlined by existing social-cognitive models, such as perceived barriers to screening, to broaden the understanding these factors have in influencing behaviour and behaviour change.
Systematic literature review of SARS-CoV-2 seroprevalence surveys in Canada through April 2021
(Elsevier, 2022-09) Major, Maria; Majowicz, Shannon E.; Oremus, Mark; Jimenez, Laura Juliana; Angulo, Frederick J.; Horton, Susan
Objectives: To estimate the proportion of the population infected by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Canada through April 2021, 16 months into the coronavirus disease 2019 (COVID-19) pandemic and 4 months after COVID-19 vaccines became available. Methods: Publication databases, preprint servers, public health databases and the grey literature were searched for seroprevalence surveys conducted in Canada from 1 November 2019 to 10 July 2021. Studies were assessed for bias using the Joanna Briggs Checklist. Numbers of infections derived from seroprevalence estimates were compared with reported cases to estimate under-ascertainment ratios. Results: In total, 12 serosurveys with 210,321 participants were identified. Three (25%) serosurveys were conducted at national level, one (8.3%) was conducted at provincial level, and eight (66.7%) were conducted at local level. All 12 serosurveys had moderate or high risk of bias. The proportion of the population infected by April 2021 was low (2.6%). The proportion of the population infected was higher in surveys of residents of long-term care facilities (43.0-86%), workers at long-term care facilities (22.4-32.4%), and workers in healthcare institutions (1.4-14%). Conclusions: As of April 2021, the proportion of the population infected by SARS-CoV-2 was low in the overall population of Canada, but was high in healthcare facilities, particularly long-term care facilities, supporting the need for vaccines.
The association between functional social support, marital status and memory in middle-aged and older adults: An analysis of the Canadian Longitudinal Study on Aging
(Elsevier, 2025) Haghighi, Paniz; Zeng, Leilei; Tyas, Suzanne L; Meyer, Samantha B; Oremus, Mark
Purpose Although several studies have reported positive associations between functional social support (FSS) and memory, few have explored how other social variables, such as marital status, may affect the magnitude and direction of this association. We examined whether marital status modifies the association between FSS and memory in a sample of community-dwelling, middle-aged and older adults. Methods Data at three timepoints, spanning six years, were analyzed from the Tracking Cohort of the Canadian Longitudinal Study on Aging (n = 10,318). Linear mixed models were used to regress memory onto FSS across all three timepoints, adjusting for multiple covariates. The moderating effect of marital status was assessed by adding its interaction with FSS in the model. Separate regression models were built for overall FSS and four subtypes (positive interactions, affectionate, emotional/informational, and tangible support). Results We found significant and positive adjusted associations for overall FSS (β: 0.07; 95 % CI: 0.01, 0.13), positive interactions (β: 0.06; 95 % CI: 0.01, 0.11), and affectionate support (β: 0.05; 95 % CI: 0.00, 0.11) with memory. However, the interaction between marital status and FSS (overall and subtypes) was not statistically significant (likelihood ratio test p-value = 0.75), indicating that FSS does not have differing effects on memory depending on marital status. Conclusion Our findings do not provide evidence to suggest that marital status affects the association between FSS and memory in middle-aged and older adults. Nonetheless, policymakers and practitioners should take a comprehensive approach when exploring how various dimensions of social relationships may uniquely influence cognitive trajectories.
Understanding the Individual and Combined Impacts of Social Isolation and Loneliness on Memory: A Sequential Explanatory Mixed Methods Study
(University of Waterloo, 2025-01-14) Kang, Ji Won; Oremus, Mark
Social isolation (SI) and loneliness (LON) are important risk factors for cognitive health; however, their combined effects on memory, a key cognitive domain, are under-researched. This thesis is the first sequential, explanatory, mixed methods study to examine how SI and LON individually and together affect memory in middle-aged and older adults. Using three waves of data from the Canadian Longitudinal Study on Aging (CLSA), spread over six years, LON was measured by the loneliness frequency question from the 10-item Center for Epidemiologic Studies Depression Scale. SI was measured by an index based on marital/cohabiting status, retirement status, social activity participation, and number/frequency of social network contacts. Memory was evaluated with combined immediate- and delayed-recall z-scores from the Rey Auditory Verbal Learning Test. Primary analyses utilized all available data across the three waves of CLSA data and retained participants with missing covariate data (n = 14,208). Linear mixed models to account for all three waves of data were used to regress combined memory scores onto SI and LON, adjusting for sociodemographic, health, functional ability, and lifestyle variables. Results showed that combined SI and LON had the greatest negative impact on memory (least-squares mean: -0.80 [95% confidence-interval: -1.22, -0.39]), followed by LON alone (-0.73 [-1.13, -0.34]), then SI alone (-0.69 [1.09, -0.29]), and lastly by experiencing neither (-0.65 [-1.05, -0.25]). Two sensitivity analyses – one excluding participants with missing covariate data from the primary analysis sample and another employing a multiple imputation approach – both confirmed these findings. The qualitative phase involved phenomenological, semi-structured interviews with ten individuals – recruited through purposive and snowball sampling – to explain the quantitative results from the perspective of middle-aged and older adults. Based on thematic analysis, qualitative participants believed that LON has a stronger negative impact on memory than SI because individuals can still engage in mental stimulation while isolated, but are less motivated to do so when feeling lonely. Participants also believed that the combination of SI and LON is most detrimental to memory, as these conditions can exacerbate each other in a feedback loop, leading those who experience both to be more prone to self-destructive behaviours. This research highlights the need for targeted interventions involving multimodal brain health programs, which simultaneously address multiple risk factors for cognitive decline – such as SI and LON – through actionable steps, including staying socially connected, finding meaning in life, engaging in cognitively stimulating physical/leisure activities, managing medical conditions, and adopting healthy lifestyle choices.