INTRODUCTION: Canada has yet to conduct high quality, prospective, population-based surveys that measure incident visual impairment, its risk factors, and adverse consequences, creating an unmet need to obtain more rigorous analysis in this regard QUESTIONS: What is the 3-year incidence of visual impairment in each province? What are the risk factors for the 3-year incidence of visual impairment? Do they include geographic, sociodemographic, lifestyle, social, health and healthcare factors? Does vision loss increase the odds of balance problems after three years? METHODS: Baseline and 3-year follow-up data were used from the Canadian Longitudinal Study on Aging. The Comprehensive Cohort included 30,097 adults ages 45-85 years old recruited from 11 sites across 7 provinces. Presenting binocular visual acuity was measured using the Early Treatment of Diabetic Retinopathy Study chart. Incidence of VI was defined as the development at follow-up of visual acuity worse than 20/40 in those with acuity better than or equal to 20/40 at baseline. Balance was measured using the one-leg balance test. Those who could not stand on one leg for at least 60 seconds were classified as having failed the test. Participants were asked about the self-report of a diagnosis of cataract, macular degeneration, or glaucoma. RESULTS: 3.88% (95% Confidence Interval (CI) 3.61, 4.17) of Canadian adults developed VI over a 3-year period. There was a high degree of variability in the incidence between Canadian provinces with a low of 1.42% in Manitoba and a high of 7.33% in Nova Scotia. Uncorrected refractive error was the leading cause of incident VI. Risk factors for incident VI included older age (odds ratio (OR)=1.07, 95% CI 1.06, 1.07), Black race (OR=2.64, 95% CI 1.36, 5.14), lower household income (OR=1.73 for those making less than $20,000 per year, 95% CI 1.24, 2.40), current smoking (OR=1.78, 95% CI 1.37, 2.32), and province. Of the 12,158 people who could stand for 60 seconds on one leg at baseline, 18% were unable to do the same at follow-up 3 years later. After adjustment for demographic and health variables, those with worse visual acuity (per 1 line) were more likely to fail the balance test at follow-up (OR=1.15, 95% CI 1.10, 1.20). Those with a report of a former (OR=1.59, 95% CI 1.17, 2.16) or current cataract (OR=1.31, 95% CI 1.01, 1.68) were more likely to fail the test at follow-up. CONCLUSION: The incidence of visual impairment is common in older Canadian adults, varies markedly between provinces, and is largely due to treatable causes. Risk factors for VI suggest sub-groups that may benefit from interventions to improve access to eye care. These data provide longitudinal evidence that vision loss increases the odds of balance problems over a 3-year period. Efforts to prevent avoidable vision loss are needed as are efforts to improve the balance of visually impaired people.

<p> This dissertation explores the nature and incidence of several non-standard work arrangements (NSWAs). Statistics confirm the growing prevalence of NSWAs. By 1995, less than one third of Canadian workers were employed in a single full-time, permanent job with a "normal" work schedule. Conventional wisdom suggests that the net effect of the increasing incidence of NSWAs is negative for workers. However, certain NSWAs potentially provide better work-life balance for employees and more flexible utilization of labour for employers. Thus, it is suggested that far too little attention has been paid to the varying nature of particular NSWAs. A typology of NSWAs, consisting of five dimensions and three types, is conceptualized. After examining the dataset and some preliminary data analysis, a modified typology of four dimensions and two types is presented and analyzed. In particular, the two key types of NSWAs are categorized as employee-friendly or employer-friendly. In addition to the typology, the workplace and worker characteristics that affect the incidence of NSWAs is examined.</p> <p> This dissertation has a quantitative research design, and utilizes Statistics Canada's 1999 Workplace and Employee Survey (WES). The chosen dataset and methodology also allow inferences to be made regarding employer strategies. Results suggest that job satisfaction is positively related to employee-friendly NSWAs but negatively related to employer-friendly NSWAs. When controlling for a range of worker and workplace variables, it was found that industry, occupation, gender, tenure, and employee participation are related to the incidence of NSWAs. Finally, consistent with existing research, only a tenuous link was found between workplace outcomes and the incidence of NSWAs. The implication is that the implementation of NSWAs is affected more by employers' strategic choices rather than economic necessity.</p> / Thesis / Doctor of Philosophy (PhD)

Background Respiratory viruses are a leading cause of acute lower respiratory infections (ALRI) in young children. The role of seasonal influenza virus in childhood ALRI is generally underappreciated. This is because the global burden of disease due to ALRI attributable to seasonal influenza virus in children is unknown. This thesis aims to estimate the global and regional hospital admissions for seasonal influenzaassociated ALRI and the possible boundaries for influenza-associated ALRI mortality in children younger than five years. The WHO has developed guidelines for influenza surveillance using severe acute respiratory infections (SARI) sentinel surveillance network. However, data from sentinel surveillance are not routinely used in estimating disease burden in a population. This thesis also aims to provide tools for estimating influenza disease burden using data from SARI sentinel surveillance in developing country settings. Methods Incidence data for influenza-associated ALRI (from passive, hospital-based studies) were collected using a systematic review of studies published between January 1, 1995 and October 31, 2010. These data were supplemented by unpublished data from 15 population-based studies that were obtained by forming a consortium of researchers (Influenza Study Group) working in developing countries. The incidence meta-estimates were applied to global and regional population estimates for 2008 to calculate the estimated number of hospitalised influenza-associated ALRI cases that year. The possible bounds for influenza-associated mortality were estimated by combining incidence estimates with in-hospital case fatality ratios and identifying studies with population-based data for influenza seasonality and monthly ALRI mortality. The data to estimate the incidence of all-cause hospitalised ALRI were collected using a systematic literature review that was supplemented with unpublished data from 24 population-based studies that were obtained by collaborating with research sites in developing countries (Severe ALRI Working Group). The hospitalised ALRI incidence meta-estimates were applied to global and regional population estimates for 2008 to calculate the estimated number of all-cause hospitalised ALRI cases that year. Data on the proportion of hospitalised ALRI cases that were positive for influenza were collected using a systematic review of the studies published between January 1, 1995 and December 31, 2011. The meta-estimates of the proportion of hospitalised ALRI cases positive for influenza were applied to the estimated number of hospitalised ALRI cases in the year 2008 to estimate the number of hospitalised influenza-associated ALRI cases globally and for the six WHO regions using this alternative method. The tools for estimating influenza disease burden using surveillance data were developed after a literature review and a survey of 27 end-users (influenza epidemiologists) in 24 countries. Results Thirty nine studies (21 from developing and 18 from industrialised regions) satisfying the eligibility criteria, provided data on the incidence of influenza-associated hospitalised ALRI. The incidence is highest in infants in the first six months of life, both in developing as well as industrialised countries. It is estimated that the incidence of hospitalised influenza-associated ALRI in children under the age of five years was about 1.5 (95% CI 1.0 to 2.3) and 1.2 (95% CI 0.9 to 1.6) per 1000 children in developing and industrialised countries respectively. This translates to about 911,000 (95% CI 617,000 to 1.4 million) hospitalisations worldwide due to influenza-associated ALRI in children younger than five years in 2008, 93% of the cases occurring in developing countries (where 90% of the global under-5 population reside). An estimated 21,500 (based on 20 studies) to 115,000 deaths (based on only 1 study) in under-five children were attributable to influenza-associated ALRI in 2008. Incidence and mortality varied substantially from year to year in any one setting. Eighty five studies (61 from developing and 24 from industrialised) reported incidence of hospitalised ALRI in children aged 0 to 4 years. It is estimated that about 11.3 (95% CI 9.5 to 13.5) million episodes of ALRI resulting in hospitalisation occurred worldwide in children aged 0 to 4 years in 2008, 92% of these occurring in developing countries. Twenty three studies (19 from developing and 4 from industrialised) reported data on proportion of hospitalised ALRI cases testing positive for influenza using laboratory tests. The estimated proportion of influenza-positive hospitalised ALRI cases was about 5.0 (95% CI 3.6 to 7) percent and 8.4 (95% CI 4.2 to 16.7) percent in developing and industrialised countries respectively. This translates to about 772,000 (95% CI 343,000 to 1.8 million) cases of influenza-associated hospitalised ALRI in children younger than five years worldwide in the year 2008. A manual (targeted at developing countries) describing the methods to estimate the disease burden associated with seasonal influenza using the various surveillance data was developed after considering the results of the preliminary survey. An electronic tool (based on a spread sheet model) to help the end-users (epidemiologists at sentinel surveillance sites and Ministries of Health) to estimate the disease burden at local and national levels was developed as an adjunct to the manual. The manual along with the electronic tool were piloted at three different sites in two developing countries (India and Ghana) and feedback from the end-users was obtained to make the version more user-friendly. The final draft of the manual along with the tool has been submitted to the WHO for final clearance. The member states and the WHO Eastern Mediterranean Regional Office decided to adopt the manual and in the first instance estimate the influenza disease burden in 8 member states having the requisite data for undertaking disease burden estimation. Conclusions Influenza is a common pathogen identified in children with ALRI and results in a substantial burden on hospital inpatient services worldwide. There are significant gaps in published data from developing countries (especially the African and Eastern Mediterranean regions of the WHO). Sufficient data to precisely estimate the role of influenza in childhood mortality from ALRI are not presently available. Effective use of sentinel surveillance data for disease burden estimation would greatly improve the quality and precision of disease burden estimates (especially those resulting in hospitalisation). Improved disease burden estimates (particularly at the national level) would inform policy makers and national governments in formulating immunization policies for vaccinating high-risk groups, and planning annual requirements for vaccines and anti-viral drugs against seasonal influenza.

No description available.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Social determinants have impacted disease states. The purpose of this study was to determine the influence of social determinants on the incidence of tuberculosis over a 20-year period for the state of New Jersey to determine interventions that can be developed for the state. The epidemiological triad (host-agent-environment) served as the theoretical foundation for this study. A quantitative series of cross sectional analyses were performed using secondary data from a New Jersey Department of Health database on population tuberculosis incidence for the state. Categorical data analyses were used to describe the data. According to study results, certain social determinants; such as gender, substance abuse, residence, and place of birth; and the age of the patient had an impact on tuberculosis incidence trend at the state level. The social change implications for this project could be that identifying the factors that impact tuberculosis incidence may reduce and lead to more targeted interventions, which in turn, would help to reduce the different kind of burdens; such as financial, social, and emotional; associated with this disease on the community where it is occurring.

Introduction: Cancer is the second leading cause of death in the United States (U.S.), after cardiovascular disease. Although there has been a continuous decline in cancer mortality rates in the U.S. over the past two decades, the Appalachian region, which extends through 13 states and 420 counties in the southeastern part of the U.S., has seen a lower decline in cancer mortality. From 1980-2014, cancer deaths decreased by almost 45%, but cancer mortality rates in rural Appalachia was 36% higher than for urban non-Appalachian counties. In terms of cancer-specific, although breast cancer mortality rates have also decreased significantly nationally, a lesser decline was seen in Appalachian counties (17.5%), compared with non-Appalachian counties (30.5%). Similarly, in all 13 Appalachian states, lung cancer mortality rates exceed national rates. Tennessee (TN) is one of the largest and most diverse states in Appalachia in terms of race/ethnicity, income, and location compared to similar largely rural states in the region like Kentucky and West Virginia. Objective: This study explores cancer incidence trends by demographic factors in northeast Tennessee. Methods: We extracted and examined electronic medical records for 322 cancer patients diagnosed with any of the top five cancers (breast, leukemias, lung, lymphoma, and prostate) between January and June 31, 2017, in a major oncological clinic in northeast TN, which attracts low-income individuals and Medicare patients. Variables included gender, race, marital status, tobacco use, and Zip codes. Descriptive statistics was used to examine the distribution, and the Spearman’s rank-order correlation to assess the relationship between demographic factors and cancer type. Results: Preliminary results showed that among women diagnosed with the top five cancers, the proportion of breast cancer (52.1%) was relatively higher than other cancers like lung (15.5%), leukemias (13.6%), multiple myeloma (9.9%) and lung (8.9%). The percentage of cancer diagnosed among men was leukemias (29.2%), lung (27.1%), prostate (21.9%), and lymphoma (21.9%). Findings further revealed a significant positive correlation of 0.396 (p =p= <0.001). Conclusions: This exploratory study examined the trends of cancer incidence in northeast Appalachia TN. Consistent with national trends, breast cancer continued to be the leading cancer diagnosed among women. However, the positive relationship between age and smoking appears to reflect that tobacco and nicotine use is associated with the likelihood to be diagnosed with any of the top five cancers. In addition, because the region is underserved and yet understudied, it is important to continue to evaluate cancer patterns as well as behavioral risk factors to identify areas for effective intervention.

Cancer is a class of diseases in which a group of cells grow uncontrollably, destroy surrounding tissue and eventually spread to other parts of the body, often leading to death. According to the American Cancer Society cancer causes accounts for 13% of all deaths. Much of the time cancer can be treated if diagnosed early. Considerable study is currently being undertaken to investigate tissue properties and their use in detecting cancer at an early stage through non invasive and non surgical methods. Oblique Incidence Diffuse Reflectance Spectrometry (OIDRS) is one such method. This thesis reports the design, fabrication and testing of a new miniaturized optical sensor probe with "side viewing" capability for oblique incidence diffuse reflectance spectrometry. The sensor probe consists of a lithographically patterned polymer waveguides chip and three micromachined positioning substrates and source/collection fibers to achieve 45 degree light incidence and collection of spatially resolved diffuse reflectance. The probe was tested at the Mayo Clinic in Rochester Minnesota. The test results show that the probe is capable of collecting data which can be analyzed to select image features to differentiate the cancerous tissue from non cancerous tissue. Using these probes, diffuse reflectance of human esophageal surface has been successfully measured for differentiation of cancerous tissues from normal ones.

D-lactic acidosis (DLA) is a disease associated with D-lactatemia, acidosis and neurological signs. However, these associations are ill-defined. Bacterial fermentation in the intestine causes increasing D-lactic acid concentrations in the body. Therefore, DLA is reported secondary to gastrointestinal diseases, such as short bowel syndrome, gastroenteritis or diarrhea. Despite intestinal origin, sudden D-lactatemia is often a result of impaired D-lactate metabolism in the body.<p> Aims of this work were to determine: 1) Influence of the presence of D-lactate or acidity on neurological disturbances; 2) Effectiveness of parenteral NaHCO3 therapy in correcting cerebrospinal acidity and DLA; 3) Prevalence of DLA in diarrheic lambs and fecal D-lactate thresholds; 4) Effectiveness of malate in preventing DLA.<p> The methodological tools consisted of animal models (calves and lambs): 1) Advanced surgical procedure in calves for long-lasting atlanto-occipital catheterizations; 2) Intravenous infusions of acids to experimentally induce acidosis; 3) Intravenous NaHCO3 therapies; 4) Sampling of cerebrospinal fluid (CSF), blood, urine and feces from experimental / treated calves or diarrheic lambs for blood gas analysis, and D-lactate separation by chromatography.<p> D-lactate entered the central nervous system (> 2 mmol/L) from the circulation following experimentally induced D-lactatemia (> 5 mmol/L) and was responsible for neurological disturbances which correlated (r = 0.9, P < 0.05) with both CSF and serum D-lactate concentrations. A zenith of neurological disturbances, ataxia was evident when D-lactate concentration exceeded 12 mmol/L (CSF) and 26 mmol/L (serum), however, a nadir of acidosis (pH 6.9) caused by HCl infusions produced only mild neurological disturbances (P < 0.05). Therapeutic NaHCO3 infusions did not result paradoxical CSF acidosis, but supportive in correcting (P < 0.05) acidosis (ÄpH + 0.11) and D-lactatemia in calves.<p> In lambs, metabolic acidosis following a range of mild to severe diarrhea was observed with a corresponding range of D-lactate concentrations in both serum (< 0.05−24.0 mmol/L) and feces (< 0.05−31.0 mmol/L). D-lactate was absorbed into the circulation when the fecal D-lactate concentration exceeded 10.2 mmol/L (threshold). In calves, moderate oral use of malate produced a > 50% (P < 0.05) decrease in fecal and serum D-lactate concentrations suggesting prebiotic properties to prevent DLA. <p> This dissertation answers the critical questions about the onset of neurological signs in D-lactic acidosis, and advances the current knowledge on the metabolism of D-lactate, the prevention and treatment of acidosis.

Objective: Urinary catheterization is associated with urinary tract infection, a common complication of stroke. We aimed to investigate the incidence and risk factors associated with urinary catheterization following acute stroke, and its impact on stroke outcome. Method: We prospectively studied a cohort of stroke patients hospitalized within 10 days after onset from August 2006 to December 2008. Kaplan-Meier method was used to estimate the cumulative incidence of Foley catheter insertion over time, and Cox proportional hazards regression analysis to evaluate the independent predictors. The impact of urinary catheterization on poor stroke outcome (modified Rankin Scale >2 or dead) at 3 months was analyzed by logistic regression. Results: Of 2789 study patients, 761 (27%) received Foley catheter insertion. Most urinary catheterization was carried out within two days of admission, with estimated cumulative incidence of 23% (95% CI, 22% to 25%) at 2 days, and 27% (25% to 29%) at 7 days. Predictors of urinary catheterization were advanced age (HR 1.01 per year; 95% CI, 1.00-1.01), increased National Institutes of Health Stroke Scale score (HR 1.08 per point; 1.07-1.09), and hemorrhagic (versus ischemic) stroke (HR 2.03; 1.69-2.44), after adjustment for gender, diabetes mellitus and previous stroke/transient ischemic attack. The influence of urinary catheterization on poor outcome at 3 months remained significant (OR 2.43; 1.65-3.58) after adjustment for relevant covariates. Conclusion: Urinary catheterization was common among hospitalized acute stroke patients, and associated with poor outcome at 3 months. Judicious use of urinary catheter in acute stroke patients is crucial to improve quality of care.