Background: Vitamin D may be important in the causal pathway to breast cancer (BC) by influencing mammographic breast density (MD). However, previous study results in postmenopausal women are inconsistent. Study objectives were to prospectively examine the relationship between biomarkers of vitamin D (25-OH-D) and percent MD in postmenopausal women at northern latitudes. Potential effect modification by exemestane therapy, calcium or genetic polymorphisms in the vitamin D pathway was also examined. Methods: This study evaluated a sub-cohort of postmenopausal women at elevated BC risk who participated in the NCIC Clinical Trials Group placebo-controlled MAP.3 trial with exemestane. Levels of 25-OH-D were measured using LC-MS/MS from serum samples collected at baseline and year 1, averaged and adjusted for month of collection. Baseline and follow-up (≥ 3 year) percent MD was centrally assessed from film and digital mammograms with Cumulus software. Multivariable linear regression was used to estimate the effect of 25-OH-D on log transformed percent MD at follow-up and on the change in percent MD from baseline. Percent MD was also dichotomized and multivariable logistic regression was used to evaluate 25-OH-D levels between 1) women with lower (<25%) compared with higher (≥25%) percent MD and 2) women with a decrease compared with no change or an increase in percent MD over time. Results: Percent MD was measured for 568 participants with a follow-up mammogram and for 388 participants with a baseline mammogram in the same format as the follow-up. The geometric mean percent MD of the follow-up mammograms was 4.3% and few women (13.4%) had percent MD ≥ 25%. The unadjusted mean 25-OH-D concentration was 36.5 ng/mL (SD=10.6) based on pooled baseline and year one samples. After controlling for age, month of sampling and potential confounders, 25-OH-D was not predictive of log transformed percent MD at follow-up (p=0.36) or with annual mean changes from baseline (p=0.33). Similarly, results from the logistic regression analyses were not statistically significant and no interactions with exemestane, calcium or genetic polymorphisms were detected. Conclusion: No association was observed between vitamin D levels and percent MD at ≥3 year follow-up or change in percent MD from baseline. / Thesis (Ph.D, Community Health & Epidemiology) -- Queen's University, 2014-03-31 11:20:23.963

Introduction: Hearing impairment is an emerging modifiable risk factor for dementia, but the relative predictive abilities of subjective and objective measures of hearing in dementia risk prediction algorithms are unclear. The objective was to develop and validate prediction models for 3-year incidence of dementia in older Canadians, and to evaluate the independent contribution of self-rated hearing impairment and audiometry-based moderate hearing loss. -- Methods: Baseline (2011 to 2015) and 3-year follow-up data from the Comprehensive cohort of the Canadian Longitudinal Study of Aging were used to build logistic regression models for 3-year incidence of dementia. Individuals who were under 55 years of age, reported physician-diagnosed dementia at baseline, and/or did not have data on dementia status at follow-up were excluded, producing a sample of 19,830 older Canadians. Hearing impairment was defined subjectively as self-reporting fair or poor hearing (versus excellent, very good, or good hearing) and was defined objectively as having a better-ear pure-tone average of the speech-frequencies (500, 1000, 2000, and 4000 Hz) above 40 dB with audiometry. -- Results: Both hearing measures were associated with dementia incidence after adjustment with other risk factors (self-rated fair/poor hearing adjusted odds ratio (aOR) 1.76, CI 0.96-3.23, audiometry-derived hearing loss aOR 2.60, CI 1.38-4.87). Audiometrically-derived hearing loss and self-rated hearing had similar population discrimination (c-statistic of model with self-rated hearing = 0.803, CI 0.752-0.859, c-statistic of model with audiometrically confirmed hearing loss = 0.808, CI 0.762-0.870) and similar calibration. -- Conclusion: Due to the accessibility of the self-reported hearing measure, the use of self-rated hearing in dementia risk prediction tools may have a larger clinical impact than audiometrically-defined hearing ability. Model performance within subgroups (e.g., older age groups, hypertension status, etc.) must be evaluated in future work to assess the magnitude of miscalibration, if any, in the use of self-reported hearing ability compared to audiometry.

La santé est une construction dynamique et multifactorielle qui a une dimension individuelle et une dimension sociale. Cette dernière peut avoir un effet direct ou indirect sur les comportements des individus et sur leurs choix de vie. L’étude de Framingham a révélé que le risque cardiovasculaire était multifactoriel et donc son estimation devait être globale. Mais les méthodes d’estimation du risque cardiovasculaire ne prennent pas en compte l’environnement de vie des individus qui favoriserait le développement des facteurs de risque modifiables. A travers ce travail, nous mettons en lumière les caractéristiques de l'environnement de diffusion des facteurs de risque cardiovasculaires modifiables : métaboliques et comportementales. Depuis des décennies, la région Nord enregistre pour les maladies cardiovasculaires des taux élevés de mortalité globale et prématurée. Nous nous sommes interrogés sur les déterminants de cette situation de la région Nord, en la comparant aux autres régions françaises, et en explorant le lien entre un risque cardiovasculaire élevé et une situation économique défavorable. Dans ce but, nous avons étudié le lien entre la distribution du risque cardiovasculaire et la distribution du revenu, en employant des critères normatifs basés sur la notion de dominance sociale en termes de pauvreté.Ce travail permet d’analyser les connaissances en rapport avec l’environnement de vie des individus et ainsi une meilleure compréhension des mécanismes de diffusion des facteurs de risque modifiables, ce qui s’inscrit dans une double perspective, réduire l’incidence et la prévalence des maladies cardiovasculaires et diminuer les inégalités sociales de santé. / Health is a dynamic and multifactor construction which has both an individual and a social dimension. The latter may have a direct or indirect effect on the behaviour of individuals and their life choices. The Framingham study has revealed that cardiovascular risk is multifactorial and, as such, its estimate should be global. However, the assessment of global cardiovascular risk methods do not take into account the living environment of individuals, which would factor the development of modifiable risk factors. Through this work, we highlight the characteristics of the environment of dissemination of modifiable cardiovascular risk factors: metabolic and behavioural. Since decades, the North region of France has, for cardiovascular diseases, a high level of global and premature mortality. We are asked about the determinants of the situation of this region, by comparing it to other French regions and by exploring the link between a high cardiovascular risk and an unfavourable economic situation. Thus, we are interested in the link between the distribution of cardiovascular risk and the distribution of income, using normative criteria based on the concept of expected social dominance in terms of poverty. Shedding a light on factors favouring the occurrence of cardiovascular problems and analyzing the knowledge about the individual’s life environment allows a better understanding of the mechanisms of diffusion of the modifiable risk factors, with a double objective to lower the incidence and prevalence of cardiovascular diseases and to reduce the social inequalities in health.

Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-06-12T13:59:52Z No. of bitstreams: 1 J??lioCesarDaCunhaLopesDissertacao2016.pdf: 5954507 bytes, checksum: 3d54d8db00b8c7c9adb70d31efdca84d (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-06-12T14:00:28Z (GMT) No. of bitstreams: 1 J??lioCesarDaCunhaLopesDissertacao2016.pdf: 5954507 bytes, checksum: 3d54d8db00b8c7c9adb70d31efdca84d (MD5) / Made available in DSpace on 2017-06-12T14:00:28Z (GMT). No. of bitstreams: 1 J??lioCesarDaCunhaLopesDissertacao2016.pdf: 5954507 bytes, checksum: 3d54d8db00b8c7c9adb70d31efdca84d (MD5) Previous issue date: 2016-03-10 / Although there is a wide variety of measures to measure the levels of agglomeration and location of firms, the areal unit problem modifiable - MAUP - is always remembered in literature as a problem in regional science. The purpose of the research is to apply the newly developed tracing measures that surpass largely the MAUP problem. With unprecedented use in Brazil, these measures assess the level of sectoral location of manufacturing industry in the Greater S??o Paulo and the results show that the fabrication industries of automotive vehicles, trailers and bodies and clothing and accessories are more localized . On the other hand, the non-metallic minerals and pulp and paper segments have a higher dispersion in relation to the other. / Embora exista uma extensa variedade de medidas para se mensurar os n??veis de aglomera????o e localiza????o das firmas, o modifiable areal unit problem ??? MAUP ??? sempre ?? lembrado na literatura como um problema na ci??ncia regional. O prop??sito da pesquisa ?? aplicar as medidas de localiza????o recentemente desenvolvidas que superam, em boa parte, o problema do MAUP. Com utiliza????o in??dita no Brasil, tais medidas avaliam o n??vel de localiza????o setorial da ind??stria da transforma????o na Regi??o Metropolitana de S??o Paulo e os resultados mostram que as ind??strias de fabrica????o de ve??culos automotores, reboques e carrocerias e de artigos de vestu??rio e acess??rios s??o mais localizadas. Por outro lado, os segmentos de minerais n??o met??licos e celulose e papel apresentam maior dispers??o em rela????o aos demais.

Objectives: The central Appalachian region of the United States is disproportionately burdened with cardiovascular diseases (CVD) and associated risk factors; however, research to inform clinical practice and policies and programs is sparse. This study aimed to examine the association between multiple modifiable risk factors for CVD and hypertension in asymptomatic patients in central Appalachia. Methods: Between January 2011 and December 2012, 1629 asymptomatic individuals from central Appalachia participated in screening for subclinical atherosclerosis. Participants were asked to report their hypertension status (yes/no). In addition, data on two nonmodifiable risk factors (sex, age) and five modifiable risk factors (obesity, diabetes mellitus, hypercholesterolemia, smoking, and sedentary lifestyle) were collected. Multivariable logistic regression analyses were conducted to assess association between hypertension and risk factors. Results: Of the 1629 participants, approximately half (49.8%) had hypertension. Among people with hypertension, 31.4% were obese and 62.3% had hypercholesterolemia. After adjusting for sex and age, obesity and diabetes mellitus were associated with a more than twofold increased odds of having hypertension (odds ratio [OR] 2.02, confidence interval [CI] 1.57–2.60 and OR 2.30, CI 1.66–3.18, respectively). Hypercholesterolemia and sedentary lifestyle were associated with higher odds for hypertension (OR 1.26, CI 1.02–1.56 and OR 1.38, CI 1.12–1.70, respectively), compared with referent groups. Having two, three, and four to five modifiable risk factors was associated with increased odds of having hypertension by about twofold (OR 1.72, CI 1.21–2.44), 2.5-fold (OR 2.55, CI 1.74–3.74), and sixfold (OR 5.96, CI 3.42–10.41), respectively. Conclusions: This study suggests that the odds of having hypertension increases with a higher number of modifiable risk factors for CVD. As such, implementing an integrated CVD program for treating and controlling modifiable risk factors for hypertension would likely decrease the future risk of CVD.

There are a myriad of studies of animal habitat use that employ the notion of “home range”. Aggregated information on animal locations provide insight into a geographically discrete units that represents the use of space by an animal. Among various methods to delineate home range is the commonly used Kernel Density Estimation (KDE). The KDE method delineates home ranges based on an animal’s Utilization Distribution (UD). Specifically, a UD estimates a three-dimensional surface representing the probability or intensity of habitat use by an animal based on known locations. The choice of bandwidth (i.e., kernel radius) in KDE determines the level of smoothing and thus, ultimately circumscribes the size and shape of an animal’s home range. The bounds of interest in a home range can then be delineated using different volume contours of the UD (e.g., 95% or 50%). Habitat variables can then be assessed within the chosen UD contour(s) to ascertain selection for certain habitat characteristics. Home range analyses that utilize the KDE method, and indeed all methods of home range delineation, are subject to the Modifiable Areal Unit Problem (MAUP) whereby the changes in the scale at which data (e.g., habitat variables) are analysed can alter the outcome of statistical analyses and resulting ecological inferences. There are two components to MAUP, the scale and zoning effects. The scale effect refers to changes to the data and, consequently the outcome of analyses as a result of aggregating data to coarser spatial units of analysis. The aggregation of data can result in a loss of fine-scale detail as well as change the observed spatial patterns. The zone effect refers to how, when holding scale constant, the delineation of areal units in space can alter data values and ultimately the results of analyses. For example, habitat features captured within 1km2 gridded sampling units may change if instead 1km2 hexagon units are used. This thesis holds there are three “modifiable” factors in home range analyses that render it subject to the MAUP. The first two relate specifically to the use of the KDE method namely, the choice of bandwidth and UD contour. The third is the grain (e.g., resolution) by which habitat variables are aggregated, which applies to KDE but also more broadly to other quantitative methods of home range delineation In the following chapters we examine the changes in values of elevation and slope that result from changes to KDE bandwidth (Chapter 2) UD contour (Chapter 3) and DEM resolution (Chapter 4). In each chapter we also examine how the observed effects of altering each individual parameter of scale (e.g., bandwidth) changes when different scales of the other two parameters are considered (e.g., contour and resolution). We expected that the scale of each parameter examined would change the observed effect of other parameters. For example, that the homogenization of data at coarser resolutions would reduce the degree of difference in variable values between UD contours of each home range. To explore the potential effects of MAUP on home range analyses we used as model population 13 northern woodland caribou (Rangifer tarandus). We created seasonal home ranges (winter, calving, summer, rut and fall) for each caribou using three different KDE bandwidths. Within each home range we delineated four contours based on differing levels of an animal’s UD. We then calculated values of elevation and slope (mean, standard deviation and coefficient of variation) using a Digital Elevation Model (DEM) aggregated to four different resolutions within the contours of each seasonal home range. We found that each parameter of scale significantly changed the values of elevation and slope within the home ranges of the model caribou population. The magnitude as well as direction of change in slope and elevation often varied depending the specific contour or season. There was a greater decrease in the variability of elevation within the fall and winter seasons at smaller KDE bandwidths. The topographic variables were significantly different between all contours of caribou home ranges and the difference between contours were in general, significantly higher in fall and winter (elevation) or calving and summer (slope). The mean and SD of slope decreased at coarser resolutions in all caribou home ranges, whereas there was no change in elevation. We also found interactive effects of all three parameters of scale, although these were not always as direct as initially anticipated. Each parameter examined (bandwidth, contour and resolution) may potentially alter the outcome of northern woodland caribou habitat analyses. We conclude that home range analyses that utilize the KDE method may be subject to MAUP by virtue the ability to modify the spatial dimensions of the units of analysis. As such, in habitat analyses using the KDE careful consideration should be given to the choice of bandwidth, UD contour and habitat variable resolution. / Graduate / 0366 / 0329 / spicym@uvic.ca

Obesity is presently one of the leading preventable causes of mortality and is an increasing issue that affects the workplace. This pilot study investigates the effects of a multidisciplinary obesity management program on employees within a community hospital setting. The purpose of this study is to assess the outcome factors of the intervention and to detect an association between the participants’ biological factors, psychological status, eating behaviors, and lifestyle components to that of their current body weight status. Methods. An evaluation of a tailored obesity management program was conducted in a corporate setting with employees of a large community hospital. The evaluation sought to determine if this program could be efficiently and effectively implemented in this corporate setting. This program also allowed an exploration of those sociological, biological, and behavioral factors that were associated with weight loss. An employee health outcomes assessment visit was used to identify, recruit and enroll overweight employees into a quasi-experimental study designed to evaluate potential impacts of a tailored weight management program. The 6-month intervention included medical assessments, nutritional coaching, activity counseling, and behavioral therapy. The following specific aims were proposed for this dissertation research: Specific Aim 1 sought to evaluate the effectiveness of the multidisciplinary weight loss program to change a series of modifiable health risk factors, body composition, clinical indicators, and biological markers from baseline to 6 months for overweight participants. Specific Aim 2 evaluated factors associated with achieving weight loss and patterns of attrition from the program. Weight and lifestyle factors included onset of obesity, family history, weight loss history, weight loss goals, self-perceptions, physical activity factors, and eating habits/patterns. Within Specific Aim 3, we determined if body composition measurements [body mass index (BMI), weight, basal metabolic rate, fat mass, percent fat, fat free mass, and total body water] correlated with standing or supine measurements of waist, hip, or thigh circumferences. We also investigated if there was a significant difference between recording measurements made in both positions. This aim sought to determine if both sets of position measurements needed to be included for subsequent weight management studies. Results. Forty-six (46) employees, with a mean age of 48.6 +/- 10.9 years and predominately female (91.3%), consented to participate in the pilot intervention, with 26 participants completing the 6 months (response = 50.9%). Statistically significant changes from baseline were seen at 6 months in the 44 participants that continued in the study after enrollment. In the intent to treat analysis, the participants, regardless of completion status, had a clinically significant (p<.0001) mean percent weight loss of 4.1% and a total weight loss of 9.3 pounds, with a corresponding 5.6% mean weight loss in those participants that completed the program. When analyzing predictors of attrition from the program, models indicated significant associations between overall program attrition and an increase in baseline systolic blood pressure (p=0.02), along with decreased compliance with eating three meals per day (p=0.04). Primary attrition (dropout < 3 months) was statistically associated with an increase in baseline systolic blood pressure (p=0.02) and decreased compliance with eating three meals per day (p=0.01). Secondary attrition (dropout between 3-6 months) was associated with decreased compliance with eating three meals per day (p=0.05) and an increase in weight loss expectations during the intervention (p=0.05). The mean absolute difference between the two techniques (standing vs. supine) was 4.14 inches for waist, hip, and thigh measurements combined. An increase in body mass index was associated with a greater magnitude of discrepancy in the measurement between the two techniques for waist circumference (p=0.02). Conclusions. The changes seen following this multidisciplinary intervention were clinically significant and advantageous for the participants. These substantial results suggest that the use of multidisciplinary weight management programs merits further investigation in larger, randomized, controlled trials.

Background: Cesarean delivery rates have been increasing since 1996, and Cesarean delivery is now the most common major operative procedure performed in the United States. Identifying risk factors for wound complications following Cesarean delivery is necessary to prevent unnecessary maternal morbidity. Methods: A case-control study was carried out and data was collected via a medical record review for patients undergoing a Cesarean delivery at the UIHC between 10/1/2011 and 12/31/2012. Results: Several modifiable risk factors were identified, and models based on patient and surgical factors performed better than the current standard NHSN risk index model. Conclusion: More robust prediction models can be created using patient and surgical factors.

I den här uppsatsen undersöks fem olika boendesegregationsindex som används för att beräkna och skildra graden av boendesegregation i samhället. Syftet är att studera hur index påverkas av slumpmässigt genererade befolkningssammansättningar av inrikes och utrikes födda, samt hur tre olika geografiska indelningar av ett område påverkar utfallet av utvalda index. Uppsatsen utförs med kvantitativ metod och deduktiv slutledning. Det data som samtliga index beräknas på är syntetiskt framtagen baserad på information om hur andelarna inrikes och utrikes födda ser ut i Sveriges tre största kommuner. Mätområdet utgörs av en hypotetisk stad som delas in på tre olika sätt varpå samtliga index testas. Beräkningar och analyser görs på stickprov för respektive index och geografisk indelning. Stickproven består alla av ett hundra element och är framtagna genom ett obundet slumpmässigt urval ur en teoretisk oändlig population simulerade befolkningssammansättningar. Den geografiska effekten undersöks genom MAUPs två delproblem, Scale Effect och Zoning Effect. Utifrån studiens resultat har följande slutsatser dragits. (1) Den slumpmässiga sammansättningen av befolkningen i den hypotetiska staden påverkade generellt index väldigt lite och låg spridning av resulterade indexvärden uppmättes för många av stickproven. De undantag som påvisades var för The Entropy Index och The Dissimilarity Index. (2) Scale Effect har stor påverkan på hur samtliga index uttrycker sig samtidigt som Zoning Effect uteblir för respektive index som testas. (3) Lägre grad av segregation uppvisas då upplösningen av den geografiska informationen är lägre.

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