910 resultados para analytical epidemiological studies


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Background Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective), the population assessed (random sample versus clinical population) and diagnostic instrument utilized.

Methods We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD)) for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders.

Results In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder), although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified.

Conclusions Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as increasing the risk of panic disorder and generalized anxiety disorder. The literature assessing anxiety disorders increasing smoking and nicotine dependence is inconsistent. Potential issues with the current literature are discussed and directions for future research are suggested.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The CIPESC (R) is a tool that informs the work of nurses in Public Health and assists in prioritizing their care in practice, management and research. It is also a powerful pedagogical instrument for the qualification of nurses within the Brazilian healthcare system. In the teaching of infectious diseases, using the CIPESC (R) assists in analyzing the interventions by encouraging clinical and epidemiological thinking regarding the health-illness process. With the purpose in mind of developing resources for teaching undergraduate nursing students and encouraging reflection regarding the process of nursing work, this article presents an experimental application of CIPESC (R), using meningococcal meningitis as an example.

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Abstract Background This study is an analysis of the prevalence of polymorphous low grade adenocarcinoma (PLGA) in epidemiological surveys of salivary tumors published in the English language from 1992 to 2012. Methods These surveys included studies from different researchers, countries and continents. The 57 surveys for which it was possible to calculate the percentage of PLGAs among all malignant minor salivary gland tumors (MMSGT) were included in this review. Results The statistical analyses show significant differences in the PLGA percentage by time period, country and continent in the studies included in this review. The percentage of PLGAs among MMSGTs varied among the studies, ranging from 0.0% to 46.8%. PLGA rates have varied over the period studied and have most recently increased. The frequency of reported PLGA cases also varied from 0.0% to 24.8% by the country in which the MMSGT studies were performed. The PLGA percentages also varied significantly by continent, with frequencies ranging from 3.9% in Asia to 20.0% in Oceania Conclusion Based on these results, we concluded that although the accuracy of PLGA diagnoses has improved, they remain a challenge for pathologists. To facilitate PLGA diagnoses, we have therefore made some suggestions for pathologists regarding tumors composed of single-layer strands of cells that form all of the histological patterns present in the tumor, consistency of the cytological appearance and uniformly positive CK7, vimentin and S100 immunohistochemistry, which indicate a single PLGA phenotype. Virtual slide The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1059098656858324

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The design of randomised controlled trials (RCTs) should incorporate characteristics (such as concealment of randomised allocation and blinding of participants and personnel) that avoid biases resulting from lack of comparability of the intervention and control groups. Empirical evidence suggests that the absence of such characteristics leads to biased intervention effect estimates, but the findings of different studies are not consistent.

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OBJECTIVES: To analyse the results of recent studies not yet included in a 2003 report of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) on occupational exposure to low-frequency electromagnetic fields as potential risk factor for neurodegenerative diseases. METHODS: A literature search was conducted in the online databases of PubMed, ISI Web of Knowledge, DIMDI and COCHRANE, as well as in specialised databases and journals. Eight studies published between January 2000 and July 2005 were included in the review. RESULTS: The findings of these studies contribute to the evidence of an association between occupational magnetic field exposure and the risk of dementia. Regarding amyotrophic lateral sclerosis, the recent results confirm earlier observations of an association with electric and electronic work and welding. Its relationship with magnetic field exposure remains unsolved. There are only few findings pointing towards an association between magnetic field exposure and Parkinson's disease. CONCLUSIONS: The epidemiological evidence for an association between occupational exposure to low-frequency electromagnetic fields and the risk of dementia has increased during the last five years. The impact of potential confounders should be evaluated in further studies.

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The increasing deployment of mobile communication base stations led to an increasing demand for epidemiological studies on possible health effects of radio frequency emissions. The methodological challenges of such studies have been critically evaluated by a panel of scientists in the fields of radiofrequency engineering/dosimetry and epidemiology. Strengths and weaknesses of previous studies have been identified. Dosimetric concepts and crucial aspects in exposure assessment were evaluated in terms of epidemiological studies on different types of outcomes. We conclude that in principle base station epidemiological studies are feasible. However, the exposure contributions from all relevant radio frequency sources have to be taken into account. The applied exposure assessment method should be piloted and validated. Short to medium term effects on physiology or health related quality of life are best investigated by cohort studies. For long term effects, groups with a potential for high exposure need to first be identified; for immediate effect, human laboratory studies are the preferred approach.

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Two molecular epidemiological studies were conducted to examine associations between genetic variation and risk of squamous cell carcinoma of the head and neck (SCCHN). In the first study, we hypothesized that genetic variation in p53 response elements (REs) may play roles in the etiology of SCCHN. We selected and genotyped five polymorphic p53 REs as well as a most frequently studied p53 codon 72 (Arg72Pro, rs1042522) polymorphism in 1,100 non-Hispanic White SCCHN patients and 1,122 age-and sex-matched cancer-free controls recruited at The University of Texas M. D. Anderson Cancer Center. In multivariate logistic regression analysis with adjustment for age, sex, smoking and drinking status, marital status and education level, we observed that the EOMES rs3806624 CC genotype had a significant effect of protection against SCCHN risk (adjusted odds ratio= 0.79, 95% confidence interval =0.64–0.98), compared with the -838TT+CT genotypes. Moreover, a significantly increased risk associated with the combined genotypes of p53 codon 72CC and EOMES -838TT+CT was observed, especially in the subgroup of non-oropharyneal cancer patients. The values of false-positive report probability were also calculated for significant findings. In the second study, we assessed the association between SCCHN risk and four potential regulatory single nucleotide polymorphisms (SNPs) of DEC1 (deleted in esophageal cancer 1) gene, a candidate tumor suppressor gene for esophageal cancer. After adjustment for age, sex, and smoking and drinking status, the variant -606CC (i.e., -249CC) homozygotes had a significantly reduced SCCHN risk (adjusted odds ratio = 0.71, 95% confidence interval = 0.52–0.99), compared with the -606TT homozygotes. Stratification analyses showed that a reduced risk associated with the -606CC genotype was more pronounced in subgroups of non-smokers, non-drinkers, younger subjects (defined as ≤ 57 years), carriers of TP53 Arg/Arg (rs1042522) genotype, patients with oropharyngeal cancer or late-stage SCCHN. Further in silico analysis revealed that the -249 T-to-C change led to a gain of a transcription factor binding site. Additional functional analysis showed that the -249T-to-C change significantly enhanced transcriptional activity of the DEC1 promoter and the DNA-protein binding activity. We conclude that the DEC1 promoter -249 T>C (rs2012775) polymorphism is functional, modulating susceptibility to SCCHN among non-Hispanic Whites. Additional large-scale, preferably population-based studies are needed to validate our findings.^

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The development of nutrition and health guidelines and policies requires reliable scientific information. Unfortunately, theoretical considerations and empirical evidence indicate that a large percentage of science-based claims rely on studies that fail to replicate. The session "Strategies to Optimize the Impact of Nutrition Surveys and Epidemiological Studies" focused on the elements of design, interpretation, and communication of nutritional surveys and epidemiological studies to enhance and encourage the production of reliable, objective evidence for use in developing dietary guidance for the public. The speakers called for more transparency of research, raw data, consistent data-staging techniques, and improved data analysis. New approaches to collecting data are urgently needed to increase the credibility and utility of findings from nutrition epidemiological studies. Such studies are critical for furthering our knowledge and understanding of the effects of diet on health.

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It has been proposed that long-term consumption of diets rich in non-digestible carbohydrates (NDCs), such as cereals, fruit and vegetables might protect against several chronic diseases, however, it has been difficult to fully establish their impact on health in epidemiology studies. The wide range properties of the different NDCs may dilution their impact when they are combined in one category for statistical comparisons in correlations or multivariate analysis. Several mechanisms have been suggested to explain the protective effects of NDCs, including increased stool bulk, dilution of carcinogens in the colonic lumen, reduced transit time, lowering pH, and bacterial fermentation to short chain fatty acids (SCFA) in the colon. However, it is very difficult to measure SCFA in humans in vivo with any accuracy, so epidemiological studies on the impact of SCFA are not feasible. Most studies use dietary fibre (DF) or Non-Starch Polysaccharides (NSP) intake to estimate the levels, but not all fibres or NSP are equally fermentable. It has been proposed that long-term consumption of diets rich in non-digestible carbohydrates (NDCs), such as cereals, fruit and vegetables might protect against several chronic diseases, however, it has been difficult to fully establish their impact on health in epidemiology studies. The wide range properties of the different NDCs may dilution their impact when they are combined in one category for statistical comparisons in correlations or multivariate analysis. Several mechanisms have been suggested to explain the protective effects of NDCs, including increased stool bulk, dilution of carcinogens in the colonic lumen, reduced transit time, lowering pH, and bacterial fermentation to short chain fatty acids (SCFA) in the colon. However, it is very difficult to measure SCFA in humans in vivo with any accuracy, so epidemiological studies on the impact of SCFA are not feasible. Most studies use dietary fibre (DF) or Non-Starch Polysaccharides (NSP) intake to estimate the levels, but not all fibres or NSP are equally fermentable. The first aim of this thesis was the development of the equations used to estimate the amount of FC that reaches the human colon and is fermented fully to SCFA by the colonic bacteria. Therefore, several studies were examined for evidence to determine the different percentages of each type of NDCs that should be included in the final model, based on how much NDCs entered the colon intact and also to what extent they were fermented to SCFA in vivo. Our model equations are FC-DF or NSP$ 1: 100 % Soluble + 10 % insoluble + 100 % NDOs¥ + 5 % TS** FC-DF or NSP 2: 100 % Soluble + 50 % insoluble + 100 % NDOs + 5 % TS FC-DF* or NSP 3: 100 % Soluble + 10 % insoluble + 100 % NDOs + 10 % TS FC-DF or NSP 4: 100 % Soluble + 50 % insoluble + 100 % NDOs + 10 % TS *DF: Dietary fibre; **TS: Total starch; $NSP: non-starch polysaccharide; ¥NDOs: non-digestible oligosaccharide The second study of this thesis aimed to examine all four predicted FC-DF and FC-NSP equations developed, to estimate FC from dietary records against urinary colonic NDCs fermentation biomarkers. The main finding of a cross-sectional comparison of habitual diet with urinary excretion of SCFA products, showed weak but significant correlation between the 24 h urinary excretion of SCFA and acetate with the estimated FC-DF 4 and FC-NSP 4 when considering all of the study participants (n = 122). Similar correlations were observed with the data for valid participants (n = 78). It was also observed that FC-DF and FC-NSP had positive correlations with 24 h urinary acetate and SCFA compared with DF and NSP alone. Hence, it could be hypothesised that using the developed index to estimate FC in the diet form dietary records, might predict SCFA production in the colon in vivo in humans. The next study in this thesis aimed to validate the FC equations developed using in vitro models of small intestinal digestion and human colon fermentation. The main findings in these in vitro studies were that there were several strong agreements between the amounts of SCFA produced after actual in vitro fermentation of single fibre and different mixtures of NDCs, and those predicted by the estimated FC from our developed equation FC-DF 4. These results which demonstrated a strong relationship between SCFA production in vitro from a range of fermentations of single fibres and mixtures of NDCs and that from the predicted FC equation, support the use of the FC equation for estimation of FC from dietary records. Therefore, we can conclude that the newly developed predicted equations have been deemed a valid and practical tool to assess SCFA productions for in vitro fermentation.

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ABSTRACT: Background: The Caries Assessment Spectrum and Treatment (CAST) is a new epidemiological instrument for detection and treatment of dental caries. Worldwide, the WHO criterion constitutes the epidemiological tool most commonly used for caries detection. The objective of the present study is to determine the levels of similarity and difference between the CAST instrument and WHO criterion on the basis of caries prevalence, dmf/DMF counts, examination time and reporting of results. Methods: An epidemiological survey was carried out in Brazil among 6-11-year-old schoolchildren. Time of examinations was recorded. dmft, dmfs, DMFT and DMFS counts and dental caries prevalence were obtained according to the WHO criterion and the CAST instrument, as well the correlation coefficient between the two instruments. Results: Four hundred nineteen children were examined. dmft and dmfs counts were 1.92 and 5.31 (CAST), 1.99 and 5.34 (WHO) with correlation coefficients (r) of 0.95 and 0.93, respectively. DMFT and DMFS counts were 0.20 and 0.33 (CAST), 0.19 and 0.30 (WHO), with r = 0.78 and r=0.72, respectively. Kappa coefficient values for intra-examiner consistency were CAST = 0.91-0.92; WHO = 0.95-0.96 and those for inter-examiner consistency were CAST = 0.90-0.96; WHO = 0.94-1.00. Mean time spent on applying CAST and WHO were 66.3 and 64.7 sec, respectively p = 0.26. The prevalence of dental caries using CAST (codes 2, 5-8) and the WHO criterion for the primary dentition were 63.0% and 65.9%, respectively, and for the permanent dentition they were 12.7% and 12.8%, respectively. Conclusions: The CAST instrument provided similar prevalence of dental caries values and dmf/DMF counts as the WHO criterion in this age group. Time spent on examining children was identical for both caries assessment methods. Presentation of results from use of the CAST instrument, in comparison to WHO criterion, allowed a more detailed reporting of stages of dental caries, which will be useful for oral health planners.

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The PARABAN project has been a Scotland-wide initiative to develop and deliver farm-specific ‘best practice’ for the control of Mycobacterium avium ssp. paratuberculosis (MAP) in cattle using ‘Knowledge Exchange’. A range of partners have been involved, including nine ‘Champion Farms’. With input from the farmer, his/her vet and PARABAN advisors, a tailored monitoring and control programme was devised for each ‘Champion Farm’, taking into account the history of the disease on the farm, the physical facilities available and farmer objectives. Culling decisions based on live animal test results were incorporated into each farm-specific programme to complement the management programme already in place to maintain each herd. Results were analysed and discussed with all the partners throughout the project and then offered for wider scrutiny at farm open days. Feedback and questions from these open days have been used to complete the ‘Knowledge Exchange’ cycle. As a major component of the PARABAN project the author collected samples from all adult animals culled from ‘Champion Farms’ at slaughter or as fallen stock, irrespective of in-life MAP test status. These were then subjected to histopathological examination by experienced veterinary pathologists and the results compared with the results from in-life MAP testing. This was intended to evaluate the contribution slaughterhouse sampling could make towards decision making for disease control on farm and formed the main aim of this thesis. In total, samples of terminal ileum and draining lymph node were collected from three-hundred and fifty-two animals. A positive result on histopathology was defined as the presence of lesions typical of MAP and also the presence of acid-fast bacteria within the sections. There was found to be fair agreement between the overall results from histopathology and serum ELISA (Kappa = 0.33), though there appeared to be some variation in agreement between the tests on the individual ‘Champion Farms’. The presence of MAP was confirmed in seven of the eight farms which contributed animals to this study, despite sometimes prolonged efforts at controlling the disease. A separate study was undertaken to make use of the archives of the Scottish Centre for Production Animal Health and Food Safety at the Veterinary School, University of Glasgow. The archive contained records of cases from across southern Scotland and northern England. Analysis of the data generated from examination of these records suggested that MAP is widespread within the Scottish cattle herd and may well be increasing