Examining the bricks and mortar of socioeconomic status: An empirical comparison of measurement methods

The impact of socioeconomic status (SES) on educational outcomes has been widely demonstrated in the fields of sociology, psychology, and educational research. Across these fields however, measurement models of SES vary, including single indicators (parental income, education, and occupation), multiple indicators, hierarchical models, and most often, an SES composite provided by the National Center for Educational Statistics. This study first reviewed the impact of SES on outcomes in higher education, followed by the various ways in which SES has been operationalized. In addition, research highlighting measurement issues in SES research was discussed. Next, several methods of measuring SES were used to predict first-year GPA at an institution of higher education. Findings and implications were reviewed with the hope of promoting more careful considerations of SES measurement

Decadal Climate Oscillations, Synoptic Variability, and Ice Core Climate Proxy Records in the Ross Sea Region, Antarctica

This thesis investigates synoptic variability in the Ross Sea region, Antarctica and develops geochemical proxies of this variability from an ice core record in Southern Victoria Land. Particular focus is given to the influence of decadal climate oscillations on synoptic conditions and potential records of these oscillations in ice core proxy records as long-­‐term records of these oscillations are important for understanding future climate change. I present an investigation of the joint influence of the El Niño Southern Oscillation (ENSO) and the Southern Annular Mode (SAM) on variability in the Amundsen Sea Low (ASL), a dominant climatological feature that strongly influences the weather in the Ross Sea region. It is shown that the positive phase of each oscillation is associated with significant strengthening of the ASL, while negative phases are associated with a weakening. Through regression analysis I show that a simple linear combination of indices representing these oscillations can explain more than 40% of the geopotential height variance in the AS region at a seasonal scale and over 70% of the variance at an annual scale. These results are consistent with the known mechanisms of ENSO and SAM interaction in the region and show that while SAM is dominant hemispherically, ENSO is only influential in the Pacific Sector. Finally it is demonstrated that a simple model of linear reinforcement and interference between the oscillations describes their influence on the variability in the ASL better than models incorporating more complex interactions. Atmospheric back-­‐trajectory modeling and cluster analysis are used to investigate synoptic variability at the Gawn Ice Piedmont (GIP) ice core site in the Ross Sea Region, Antarctica. I identify two dominant air-­‐mass trajectory clusters: oceanic – cyclonic and continental trajectories. My analysis shows that oceanic – cyclonic trajectories peak during April (southern hemisphere winter), while continental trajectories reach their maximum during December (summer). A causal association is demonstrated between ENSO and the frequency of oceanic – cyclonic trajectories originating from the Ross Sea region. In contrast, it is shown that the Southern Annular Mode has little influence on the frequency of cyclonic clusters. I then develop proxy records for the synoptic variability using a shallow firn core from the GIP site containing 8 years of geochemical record. Continental trajectories correlate with concentrations of nitrate (NO3), which is sourced from stratospheric air-­‐masses descending over the Antarctic interior. Oceanic – cyclonic trajectory clusters strongly correlate with deuterium excess at seasonal and inter-­‐annual scales, a proxy sensitive to changes in relative humidity and sea surface temperature (SST) in the in the Ross and Amundsen Seas. Decadal variability in the frequency of oceanic – cyclonic trajectories is discussed with respect to ENSO, SAM, and changes in SST and sea ice extent

Effectiveness of a Community Program for Older Adults with Type 2 Diabetes and Multimorbidity: A Pragmatic Randomized Controlled Trial

Background Type II diabetes mellitus (T2DM) affects upwards of 25% of Canadian older adults and is associated with high comorbidity and burden. Studies show that lifestyle factors and self-management are associated with improved health outcomes, but many studies lack rigour or exclude older adults, particularly those with multimorbidity. More evidence is needed on the effectiveness of community-based self-management programs in older adults with T2DM and multimorbidity. The study purpose is to evaluate the effect of a community-based intervention versus usual care on physical functioning, mental health, depressive symptoms, anxiety, self-efficacy, self-management, and healthcare costs in older adults with T2DM and 2 or more comorbidities. Methods Community-living older adults with T2DM and two or more chronic conditions were recruited from three Primary Care Networks (PCNs) in Alberta, Canada. Participants were randomly allocated to the intervention or control group in this pragmatic randomized controlled trial comparing the intervention to usual care. The intervention involved up to three in-home visits, a monthly group wellness program, monthly case conferencing, and care coordination. The primary outcome was physical functioning. Secondary outcomes included mental functioning, anxiety, depressive symptoms, self-efficacy, self-management, and the cost of healthcare service use. Intention-to-treat analysis was performed using ANCOVA modeling. Results Of 132 enrolled participants (70-Intervention, 62-Control), 42% were 75 years or older, 55% were female, and over 75% had at least six chronic conditions (in addition to T2DM). No significant group differences were seen for the baseline to six-month change in physical functioning (mean difference: -0.74; 95% CI: − 3.22, 1.74; p-value: 0.56), mental functioning (mean difference: 1.24; 95% CI: − 1.12, 3.60; p-value: 0.30), or other secondary outcomes.. Conclusion No significant group differences were seen for the primary outcome, physical functioning (PCS). Program implementation, baseline differences between study arms and chronic disease management services that are part of usual care may have contributed to the modest study results. Fruitful areas for future research include capturing clinical outcome measures and exploring the impact of varying the type and intensity of key intervention components such as exercise and diet

Decadal Climate Oscillations, Synoptic Variability, and Ice Core Climate Proxy Records in the Ross Sea Region, Antarctica

This thesis investigates synoptic variability in the Ross Sea region, Antarctica and develops geochemical proxies of this variability from an ice core record in Southern Victoria Land. Particular focus is given to the influence of decadal climate oscillations on synoptic conditions and potential records of these oscillations in ice core proxy records as long-­‐term records of these oscillations are important for understanding future climate change. I present an investigation of the joint influence of the El Niño Southern Oscillation (ENSO) and the Southern Annular Mode (SAM) on variability in the Amundsen Sea Low (ASL), a dominant climatological feature that strongly influences the weather in the Ross Sea region. It is shown that the positive phase of each oscillation is associated with significant strengthening of the ASL, while negative phases are associated with a weakening. Through regression analysis I show that a simple linear combination of indices representing these oscillations can explain more than 40% of the geopotential height variance in the AS region at a seasonal scale and over 70% of the variance at an annual scale. These results are consistent with the known mechanisms of ENSO and SAM interaction in the region and show that while SAM is dominant hemispherically, ENSO is only influential in the Pacific Sector. Finally it is demonstrated that a simple model of linear reinforcement and interference between the oscillations describes their influence on the variability in the ASL better than models incorporating more complex interactions. Atmospheric back-­‐trajectory modeling and cluster analysis are used to investigate synoptic variability at the Gawn Ice Piedmont (GIP) ice core site in the Ross Sea Region, Antarctica. I identify two dominant air-­‐mass trajectory clusters: oceanic – cyclonic and continental trajectories. My analysis shows that oceanic – cyclonic trajectories peak during April (southern hemisphere winter), while continental trajectories reach their maximum during December (summer). A causal association is demonstrated between ENSO and the frequency of oceanic – cyclonic trajectories originating from the Ross Sea region. In contrast, it is shown that the Southern Annular Mode has little influence on the frequency of cyclonic clusters. I then develop proxy records for the synoptic variability using a shallow firn core from the GIP site containing 8 years of geochemical record. Continental trajectories correlate with concentrations of nitrate (NO3), which is sourced from stratospheric air-­‐masses descending over the Antarctic interior. Oceanic – cyclonic trajectory clusters strongly correlate with deuterium excess at seasonal and inter-­‐annual scales, a proxy sensitive to changes in relative humidity and sea surface temperature (SST) in the in the Ross and Amundsen Seas. Decadal variability in the frequency of oceanic – cyclonic trajectories is discussed with respect to ENSO, SAM, and changes in SST and sea ice extent

Effect of socio-demographic and health factors on the association between multimorbidity and acute care service use: population-based survey linked to health administrative data

Abstract Background This study explores how socio-demographic and health factors shape the relationship between multimorbidity and one-year acute care service use (i.e., hospital, emergency department visits) in older adults in Ontario, Canada. Methods We linked multiple cycles (2005–2006, 2007–2008, 2009–2010, 2011–2012) of the Canadian Community Health Survey (CCHS) to health administrative data to create a cohort of adults aged 65 and older. Administrative data were used to estimate one-year service use and to identify 12 chronic conditions used to measure multimorbidity. We examined the relationship between multimorbidity and service use stratified by a range of socio-demographic and health variables available from the CCHS. Logistic and Poisson regressions were used to explore the association between multimorbidity and service use and the role of socio-demographic factors in this relationship. Results Of the 28,361 members of the study sample, 60% were between the ages of 65 and 74 years, 57% were female, 72% were non-immigrant, and over 75% lived in an urban area. Emergency department visits and hospitalizations consistently increased with the level of multimorbidity. This study did not find strong evidence of moderator or interaction effects across a range of socio-demographic factors. Stratified analyses revealed further patterns, with many being similar for both services – e.g., the odds ratios were higher at all levels of multimorbidity for men, older age groups, and those with lower household income. Rurality and immigrant status influenced emergency department use (higher in rural residents and non-immigrants) but not hospitalizations. Multimorbidity and the range of socio-demographic variables remained significant predictors of service use in the regressions. Conclusions Strong evidence links multimorbidity with increased acute care service use. This study showed that a range of factors did not modify this relationship. Nevertheless, the factors were independently associated with acute care service use, pointing to modifiable risk factors that can be the focus of resource allocation and intervention design to reduce service use in those with multimorbidity. The study’s results suggest that optimizing acute care service use in older adults requires attention to both multimorbidity and social determinants, with programs that are multifactorial and integrated across the health and social service sectors