Att konsumera kosttillskott ökar i dagens samhälle. Exempel på kosttillskott är energigivande tillskott, prestationshöjande tillskott samt vitaminer och mineraler. En sammanställning av enkätundersökningar i Sverige visar att 61 % av männen och 41 % av kvinnorna konsumerar kosttillskott. Träningsverksamma upplever att produkterna är välgörande och ger positiva effekter på träningen, trots att riskerna med konsumtion av kosttillskott är omdebatterat och ett delvis obeforskat område. Bland träningsverksamma inom styrketräning förekommer även konsumtion av dopningspreparat. Dopning innebär att påverka eller förändra prestationer med olika substanser. Det finns olika slags dopningspreparat och anabola androgena steroider (AAS) är vanligast. Prevalensen av AAS har ökat under 2000-talet. I uppsatsen redovisas omfattningen av konsumtion av kosttillskott och dopningspreparat i Västmanlands län. Köns- och åldersskillnader samt samband mellan konsumtion och träningsform redovisas. Analyser har genomförts på enkätdata från Västmanlands Idrottsförbund, utifrån deras arbete med anti-dopning i Västmanland. Resultaten visar att det är vanligast att män i 17 – 30 års ålder konsumerar kosttillskott. Sannolikheten för att ha en hög konsumtion av kosttillskott ökar vid styrketräning. Socialkognitiv teori används föra att tolka den sociala aspekten på konsumtionen och ger en djupare förståelse för hur beteendet att konsumera kosttillskott och/eller dopningspreparat kan uppstå hos en individ. / Consuming dietary supplements is common in today's society. Examples of dietary supplements is energizing supplements, performance enhancing supplements and vitamins and minerals. A compilation of surveys in Sweden show that 61% of men and 41% of women consume dietary supplements. Athletes are experiencing that the products are beneficial and provides positive effects on the performance, even though there is a lack of knowledge about all the risks of consuming dietary supplement and a field partly un-researched. Consumption of doping substances also occur among athletes. Doping means to affect or change the performance with various substances. There are different types of doping substances, where anabolic androgenic steroids (AAS) are the most common. The prevalence of AAS has increased during the 2000s. The prevalence of the consumption of dietary supplements and doping in Västmanlands län are presented in the present study. Results revealed differences in gender and age and the relationship between consumption and exercise. Analyses have been performed on data from Västmanland Sports Federation, which through its anti-doping work conducted a survey in Västmanlands län. The results show that it is most common among men between the ages 17 – 30 to consume dietary supplements and to consume a few times a week or more often. The likelihood of consuming dietary supplements increases with strength training. Social cognitive theory is being used to interpret the social aspect of consumption and provides a deeper understanding for how a behavior can be developed in an individual.

Correlated data frequently arise from epidemiological studies, especially familial and longitudinal studies. Longitudinal design has been used by researchers to investigate the changes of certain characteristics over time at the individual level as well as how potential factors influence the changes. Familial studies are often designed to investigate the dependence of health conditions among family members. Various models have been developed for this type of multivariate data, and a wide variety of estimation techniques have been proposed. However, data collected from observational studies are often far from perfect, as measurement error may arise from different sources such as defective measuring systems, diagnostic tests without gold references, and self-reports. Under such scenarios only rough surrogate variables are measured. Measurement error in covariates in various regression models has been discussed extensively in the literature. It is well known that naive approaches ignoring covariate error often lead to inconsistent estimators for model parameters. In this thesis, we develop inferential procedures for analyzing correlated data with response measurement error. We consider three scenarios: (i) likelihood-based inferences for generalized linear mixed models when the continuous response is subject to nonlinear measurement errors; (ii) estimating equations methods for binary responses with misclassifications; and (iii) estimating equations methods for ordinal responses when the response variable and categorical/ordinal covariates are subject to misclassifications. The first problem arises when the continuous response variable is difficult to measure. When the true response is defined as the long-term average of measurements, a single measurement is considered as an error-contaminated surrogate. We focus on generalized linear mixed models with nonlinear response error and study the induced bias in naive estimates. We propose likelihood-based methods that can yield consistent and efficient estimators for both fixed-effects and variance parameters. Results of simulation studies and analysis of a data set from the Framingham Heart Study are presented. Marginal models have been widely used for correlated binary, categorical, and ordinal data. The regression parameters characterize the marginal mean of a single outcome, without conditioning on other outcomes or unobserved random effects. The generalized estimating equations (GEE) approach, introduced by Liang and Zeger (1986), only models the first two moments of the responses with associations being treated as nuisance characteristics. For some clustered studies especially familial studies, however, the association structure may be of scientific interest. With binary data Prentice (1988) proposed additional estimating equations that allow one to model pairwise correlations. We consider marginal models for correlated binary data with misclassified responses. We develop “corrected” estimating equations approaches that can yield consistent estimators for both mean and association parameters. The idea is related to Nakamura (1990) that is originally developed for correcting bias induced by additive covariate measurement error under generalized linear models. Our approaches can also handle correlated misclassifications rather than a simple misclassification process as considered by Neuhaus (2002) for clustered binary data under generalized linear mixed models. We extend our methods and further develop marginal approaches for analysis of longitudinal ordinal data with misclassification in both responses and categorical covariates. Simulation studies show that our proposed methods perform very well under a variety of scenarios. Results from application of the proposed methods to real data are presented. Measurement error can be coupled with many other features in the data, e.g., complex survey designs, that can complicate inferential procedures. We explore combining survey weights and misclassification in ordinal covariates in logistic regression analyses. We propose an approach that incorporates survey weights into estimating equations to yield design-based unbiased estimators. In the final part of the thesis we outline some directions for future work, such as transition models and semiparametric models for longitudinal data with both incomplete observations and measurement error. Missing data is another common feature in applications. Developing novel statistical techniques for dealing with both missing data and measurement error can be beneficial.

Studies of diagnostic accuracy often report paired tests for sensitivity and specificity that can be pooled separately to produce summary estimates in a meta-analysis. This was done recently for a systematic review of radiographers' reporting accuracy of plain radiographs. The problem with pooling sensitivities and specificities separately is that it does not acknowledge any possible (negative) correlation between these two measures. A possible cause of this negative correlation is that different thresholds are used in studies to define abnormal and normal radiographs because of implicit variations in thresholds that occur when radiographers' report plain radiographs. A method that allows for the correlation that can exist between pairs of sensitivity and specificity within a study using a random effects approach is the bivariate model. When estimates of accuracy as a fixed-effects model were pooled separately, radiographers' reported plain radiographs in clinical practice at 93% (95% confidence interval (CI) 92-93%) sensitivity and 98% (95% CI 98-98%) specificity. The bivariate model produced the same summary estimates of sensitivity and specificity but with wider confidence intervals (93% (95% CI 91-95%) and 98% (95% CI 96-98%), respectively) that take into account the heterogeneity beyond chance between studies. This method also allowed us to calculate a 95% confidence ellipse around the mean values of sensitivity and specificity and a 95% prediction ellipse for individual values of sensitivity and specificity. The bivariate model is an improvement on pooling sensitivity and specificity separately when there is a threshold effect, and it is the preferred method of choice.

Made available in DSpace on 2014-06-11T19:27:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-10Bitstream added on 2014-06-13T20:35:36Z : No. of bitstreams: 1 buso_ds_me_araca.pdf: 1499027 bytes, checksum: 9471e49d685f30b7f59eb8407cbc0c71 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Milhões de pessoas são mordidas por cães todos os anos no Brasil e no mundo. Por meio de uma análise de casos e de um estudo caso-controle, objetivou-se caracterizar as agressões caninas e estabelecer fatores de risco para a ocorrência de agressões caninas a pessoas no Município de Araçatuba, SP. Foi realizado o teste qui-quadrado para variáveis categóricas e o teste t para variáveis numéricas, seguidos da análise estatística de Regressão Logística Binária, estabelecendo-se então o “Odds ratio” (OR) para determinadas variáveis. A maioria dos cães (71%) foi recebida como presente, sendo a busca por companhia o principal motivo de aquisição. Entre as vítimas, houve predomínio do sexo masculino em crianças e do sexo feminino em idosos. O cão agressor ter escapado (18,7%) foi a principal situação envolvida nas agressões. Consideraram-se fatores de risco o número de crianças do domicílio (OR = 1,70; IC 95% 1,03-2,82), o sexo do cão (machos, OR = 3,08; IC 95% 1,41-6,73), o estado reprodutivo (não esterilizados, OR = 4,28; IC 95% 1,05-17,45), o recebimento do animal como presente (OR = 3,99; IC 95% 1,85-8,64), a aquisição para proteção do domicílio (OR = 9,23; IC 95% 2,25-37,81) e a número de situações resultantes em agressividade (OR = 1,35; IC 95% 1,16-1,57). O número de adultos no domicílio (OR=0,65; IC 95% 0,47-0,91) foi associado negativamente à ocorrência de mordeduras. Foi possível equacionara influência conjunta de tais variáveis sobre a probabilidade de ocorrência de agressão. Estes resultados permitem que se estabeleçam programas preventivos e de posse responsável para agressões visando esclarecer sobre formas mais seguras de interação com cães, sobre os riscos e como evitá-los / Millions of people are bitten by dogs each year in Brazil and worldwide. Through an analysis of cases and a case-control study, the aim of this paper was to characterize the epidemiology of canine aggression from occurring and to establish risk factors for the occurrence of canine aggression to people in the city of Araçatuba, SP. We performed the chi-square test for categorical variables and t test for numerical variables, followed by Binary Logistic Regression, settling then the odds ratio (OR) for certain variables. Most dogs (71%) were received as gifts, search for company being the main reason for the acquisition. Among the victims, children were predominantly male and elderly were predominantly females. The dogs had escaped (18.7%) was the main situation involving attacks. Were considered risk factors the number of children in the household (OR = 1.70, 95% CI 1.03-2.82), sex of the dog (males, OR = 3.08, 95% 1.41-6.73), reproductive status (intact, OR = 4.28, 95% CI 1.05-17.45), receipt of the animal as a present (OR = 3.99, 95% CI 1 0.85-8, 64), acquisition for protection of the home (OR = 9.23, 95% CI 2.25- 37.81) and the counting of situations resulting in aggressiveness (OR = 1.35, 95% 1.16-1.57). The number of adults in the household (OR = 0.65, 95% CI 0.47-0.91) was negatively associated with the occurrence of bites. It was possible to consider the combined influence of these variables on the likelihood of aggression. These results allow us to establish dog bites preventive and responsible dog ownership programs that aim to clarify about the safest ways to interaction with dogs, the risks and how to avoid them

O presente estudo se baseou em levantamentos retrospectivos e prospectivos obtidos de bovinos abatidos no Frigorífico Bertin, em Lins-SP. No primeiro levantamento consultaram-se os registros do Serviço de Inspeção Federal de ocorrência de alterações hepáticas em 1.568.821 bovinos (85% machos e 15% fêmeas), proveniente de seis Estados (SP, MS, PR, GO, MT e MG) durante os anos de 2002 a 2006. Consideraram-se os animais abatidos no último trimestre de cada ano como terminados em confinamento, sendo os demais criados continuamente em regime extensivo. Os abscessos hepáticos (1,60%) foram a segunda mais freqüente alteração hepática após a teleangectasia (1,67%). A freqüência desses abscessos foi maior em bovinos confinados (2,54%) que nos criados extensivamente (1,28%) e em fêmeas (1,85%) que em machos (1,56%). O confinamento aumenta o fator de risco (FR) de surgimento de abscessos hepáticos na ordem de 2,01 vezes. Maior freqüência de abscessos foi registrada em bovinos oriundos do Paraná, em ambos os sistemas de terminação. No levantamento prospectivo foram acompanhados o abate de 1.617 bovinos nos meses de dezembro de 2007 (n=858) e outubro de 2008 (n=759). Os abscessos hepáticos foram registrados de acordo com a freqüência, tamanho, número e localização dos mesmos em 1.617 animais; a mucosa ruminal foi avaliada (n=1.397) quanto à presença de ruminite, sua classificação e área afetada; e os pulmões (n=759) examinados para a detecção de hepatização pulmonar nas diferentes regiões, lóbos e lóbulos pulmonares, assim como grau de acometimento nos lóbulos. Foram detectados abscessos hepáticos, ruminites e pulmões hepatizados em 3,29%, 11,88% e 8,30% dos animais, respectivamente. Os abscessos estiveram igualmente distribuídos em todas as quatro regiões hepáticas, e na maioria dos casos (78,26%) os mesmos eram de pequeno tamanho (< 2,5cm) e número (até dois/órgão). Foram encontrados quatro tipos de ruminites, sendo a mais freqüente a retração cicatricial (54,22%), seguido de retalhos aderentes (24,10%), vilosidades aderidas (13,25%) e ruminite erosiva (8,43%). Em 32,53% desses casos à área afetada do rúmen ultrapassava os 300cm2. Animais com ruminite apresentavam um altíssimo risco (FR=12,67x) de manifestar abscessos hepáticos e hepatização pulmonar (FR=5,8x), com destaque para a ruminite erosiva. A hepatização pulmonar foi mais freqüente na região ventral (71,4%) que dorsal (28,6%), nos lóbulos esquerdos (59,79%) que direitos (40,21%) e na maioria dos casos acometia apenas um lóbulo (53,97%) não atingindo a hepatização mais do que 50% deste (66,6%). Abscessos hepáticos ocorreram com maior freqüência quando concomitantemente um único lóbulo pulmonar era acometido (FR=3,0x) e este se apresentava com menos de 50% de seu parênquima hepatizado (FR=11,61x). / A retrospective and prospective survey was carried out in cattle slaughtered in a private abattoir in the State of Sao Paulo, Brazil. The first survey was based on the reports done by the Federal Inspection Service of the liver condemnations among 1,568,821 cattle (85% steers; 15% cows and heifers) from six different Brazilian states during 2002 and 2006. Feedlot cattle were mostly slaughtered in the last trimester of each year, while the cattle bred extensively were in the remaining months. The abscesses (1.60%) were the second highest cause of liver condemnation after telangiectasis (1.67%). The frequency of liver abscesses were higher in feedlot cattle (2.54%) than those bred extensively (1.28%), female (1.85%) than male (1.56%). Feedlot increased the outcome (odds ratio OD= 2.01x) of liver abscess. The highest frequency of liver abscess was detected in feedlot and extensively bred cattle from the Parana state. The prospective survey was carried out following the slaughtering of 1,617 cattle during the months of December 2007 (n=858) and October 2008 (n=759). The abscesses frequency, size, number and location in the liver were recorded in all animals; the rumen mucosa (n=1,397) was examined for the presence, type and size of ruminitis; the lungs (n=759) were also examined for detection of consolidation, evaluating the affected region, number of lobes and lesion score. The following frequencies were seen: liver abscess (3.29%), ruminitis (11.88%) and lung consolidation (8.30%). The abscesses were equally distributed in all hepatic regions; most abscesses (78.2%) were small (< 2.5cm) and present in low number (1-2/liver). Four different types of ruminitis were seen: scars (54.22%), adherent contents (21.10%), clumped villi (13.25%) and erosive ruminitis (8.43%). In many cases (32.53%) the ruminitis spread to an area larger than 300cm2. Cattle with ruminitis had a very high risk of contracting liver abscesses (OD=12.67x) and lung consolidation (OR= 5.8x), principally with erosive ruminitis. Lung consolidation was mostly seen in the ventral (71.4%) than dorsal areas (28.6%), in the left (59.79%) than right lobes (40.21%); in most cases a single lobe was affected (53.97%) and less than 50% of the lobe was consolidated (66.6%). Liver abscesses were commonly seen in cattle with a single lobe (OD=3.0x) and less than 50% of this lobe consolidated (OR=11.61x).

The tetrachoric correlation describes the linear relation between two continuous variables that have each been measured on a dichotomous scale. The treatment of the point estimate, standard error, interval estimate, and sample size requirement for the tetrachoric correlation is cursory and incomplete in modern psychometric and behavioral statistics texts. A new and simple method of accurately approximating the tetrachoric correlation is introduced. The tetrachoric approximation is then used to derive a simple standard error, confidence interval, and sample size planning formula. The new confidence interval is shown to perform far better than the confidence interval computed by SAS. A method to improve the SAS confidence interval is proposed. All of the new results are computationally simple and are ideally suited for textbook and classroom presentations.

Chronic kidney disease greatly raises cardiovascular disease risk. Heart disease and death risk grow proportionately with renal disease progression. Investigate the link between cardiovascular disease prevalence and chronic renal disease severity and mortality using meta-analysis. In this study, 155 publications were found after searching several databases (including PubMed and Google Scholar). 48 studies that matched the inclusion criteria were included in the literature review, however, only 20 were included in the meta-analysis. 17101 people had CKD, while 8883 had CVD or non-CVD. Using the R programming language, a meta-analysis was performed to get a pooled impact of the influence of CVD on the severity of CKD (odds ratio OR), and a funnel plot was also generated to check for publication bias. The outcomes of the meta-analysis indicate that cardiovascular disease has a moderate impact on the severity of chronic kidney disease (OR=2.28, 95% CI, 1.90-2.73). All data will give essential insights into the epidemiology of the cardiovascular disease in chronic kidney disease (CKD), disclose the influence of individual risk variables on bad outcomes, and serve as the platform for future interventional research. Further investigation of the particular (non-traditional) risk factors associated with the renal illness that contribute to accelerated atherosclerosis in this population is necessary to improve the efficacy of cardiovascular treatments for patients with CKD. The purpose of this research is to determine whether and how these variables affect the development of CKD. / <p>Utbytesstudent.</p>

The inverse sinh transformation on the Woolf interval is used to calculate the confidence interval for the odds ratio and the relative risk in a 2 x 2 table. According to Robert Newcombe, the new interval should improve the coverage probabilities and shorten the width of the confidence interval for these ratios, but the new interval requires evaluation of coverage properties. In this thesis, we will evaluate the exact coverage properties of this modified interval in extreme cases. Also, we will compare the coverage properties of this new interval to other widely-used adjusted intervals. Through comparisons of exact coverage probabilities and interval widths, we will discover if Newcombe's inverse sinh transformation provides better coverage properties than the adjusted methods.

The corona virus disease of 2019 (Covid-19) is a deadly viral infection rampaging the world since 2019. Health practitioners have identified co-morbidities as one of the factors contributing to the severity of the disease among patients, with diabetes being one of the leading co-morbid. A systematic search was performed on PubMed, Google Scholar and Science hub databases to obtain articles that have addressed the link between diabetes and severity in Covid-19 infection. A meta-analysis to obtain a pooled effect of the effect of diabetes on the severity of Covid-19 (odd ratio OR) was calculated using R programming language and a funnel plot to check for publication bias was also plotted. Twelve studies with 3,180,125 diabetic patients with confirmed cases of Covid-19 (out of 61,820,553 confirmed Covid-19 participants) were included for the meta-analysis. The obtained pooled effect of diabetes on the severity of Covid-19 infection was (OR=1.47; 95% CI 1.33-1.63). From the meta-analysis results; Age, diabetic complications and drugs for the treatment of diabetes were identified as possible co-factors to the diabetic effect on Covid-19 infection, as diabetes was seen to be significantly related to its severity but not mortality. It is therefore very important for diabetic patients to adhere strictly to every laid down regulation regarding Covid-19. More clinical research on alternative diabetic therapy is needed as this will reduce the negative effect of insulin usage.

No / Medical statistics is a vast and ever-growing field of academic endeavour, with direct application to developing the robustness of the evidence base in all areas of medicine. Although the complexity of available statistical techniques has continued to increase, fuelled by the rapid data processing capabilities of even desktop/laptop computers, medical practitioners can go a long way towards creating, critically evaluating and assimilating this evidence with an understanding of just a few key statistical concepts. While the concepts of statistics and ethics are not common bedfellows, it should be emphasised that a statistically flawed study is also an unethical study.[1] This review will outline some of these key concepts and explain how to interpret the output of some commonly used statistical analyses. Examples will be confined to two-group tests on independent samples, using both a continuous and a dichotomous/binary outcome measure.