64 resultados para Cohort Studies


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Purpose: To describe longitudinal changes in leisure-time sedentary behavior among girls, during early to mid-adolescence. Methods: A 2.5-year prospective cohort study, comprising 5 data collections, 6 months apart, between 2000 and 2002. Girls aged 12–15 years (n = 200) from 8 high schools located in Sydney, Australia, self-reported the usual time spent each week in a comprehensive range of sedentary behaviors.  Results: Retention rate for the study was 82%. Girls aged 12.8 years spent approximately 45% of their discretionary time in sedentary behavior, which increased to 63% at age 14.9 years. Watching TV, videos, and playing video games (small screen recreation; SSR) was the most popular sedentary pastime, accounting for 33% of time spent in sedentariness, followed by homework and reading (25%). Sedentary behavior increased 1.4 and 3.3 hours on week and weekend days, respectively. On weekdays, increased time was spent on hobbies (27 min/day) and on weekend days, increased time was spent sitting around talking with friends (60 min/day), computer use (37 min/day), and television viewing (34 min/day). Conclusions: Among girls, the transition between early and mid-adolescence was accompanied by a significant increase in leisure-time sedentary behavior. Interventions to reduce sedentariness among adolescent girls are best to focus on weekend behaviors. Studies seeking to examine the association between inactivity and the development of chronic health problems need to examine a diverse range of activities that comprehensively measure sedentariness. This information will provide a better understanding of inactivity patterns among adolescent girls.

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Background : Previous epidemiological studies have investigated the relationship between individual nutrients such as vitamin D and vitamin B12 and mammographic density, a strong marker of breast cancer risk [1], with varied results. There has been limited research on overall dietary patterns and most studies have focused on adult dietary patterns [2]. We examine prospective data to determine whether dietary patterns from childhood to adult life affect mammographic density.

Methods : The Medical Research Council National Survey of Health and Development is a national representative sample of 2,815 men and 2,547 women followed since their birth in March 1946 [3]. A wealth of medical and social data has been collected in over 25 follow-ups by home visits, medical examinations and postal questionnaires. Dietary intakes at age 4 years were determined by 24-hour recalls and in adulthood (ages 36, 43 years) by 5-day food records. Copies of the mammograms (two views for each breast) taken when the women were closest to age 50 years were obtained from the relevant NHS centres. A total of 1,319 women were followed up since birth in 1946 for whom a mammogram at age 50 years was retrieved, and the percentage mammographic density was measured using the computer-assisted threshold method for all 1,161 women. Breast cancer incidence for the whole cohort is being ascertained through the National Health Service Central Register.

Statistical analysis : Reduced rank regression analysis, a relatively new approach to dietary pattern analysis, is being used to identify dietary patterns associated with mammographic density [4]. This approach identifies patterns in food intake that are predictive of an intermediate outcome of the disease process, such as mammographic density, and subsequently examines the relationship between the identified dietary patterns and breast cancer risk.

Results : Preliminary analyses so far suggest that variations in dietary patterns in adulthood might explain more than 10% of the variation in percentage mammographic density at age 50 years (age 36 years: 13%; age 43 years: 14%), with variations in patterns in childhood explaining slightly less. Further work is being carried out on the characteristics of these dietary patterns and their effects on percentage mammographic density and its two components (that is, absolute areas of dense and nondense tissues) and on breast cancer risk, after adjusting for socioeconomic status, anthropometric variables and reproductive factors.

Conclusion : The present study will provide for the first time information on the relationship between dietary patterns across the life course and mammographic density, and will help to clarify the pathways through which diet may affect breast cancer risk.

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Purpose: Most women with early-stage breast cancer believe that psychosocial factors are an important influence over whether their cancer will recur. Studies of the issue have produced conflicting results.

Patients and Methods: A population-based sample of 708 Australian women diagnosed before age 60 years with nonmetastatic breast cancer was observed for a median of 8.2 years. Depression and anxiety, coping style, and social support were assessed at a median of 11 months after diagnosis. Hazard ratios for distant disease-free survival (DDFS) and overall survival (OS) associated with psychosocial factors were estimated separately using Cox proportional hazards survival models, with and without adjustment for known prognostic factors.

Results:
Distant recurrence occurred in 209 (33%) of 638 assessable patients, and 170 (24%) of 708 patients died during the follow-up period. There were no statistically significant associations between any of the measured psychosocial factors and DDFS or OS from the adjusted analyses. From unadjusted analyses, associations between greater anxious preoccupation and poorer DDFS and OS were observed (P = .02). These associations were no longer evident after adjustment for established prognostic factors; greater anxious preoccupation was associated with younger age at diagnosis (P = .03), higher tumor grade (P = .02), and greater number of involved axillary nodes (P = .008).

Conclusion:
The findings do not support the measured psychosocial factors being an important influence on breast cancer outcomes. Interventions for adverse psychosocial factors are warranted to improve quality of life but should not be expected to improve survival.

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Student feedback is essential to enable lecturers to understand whether attempts to improve learning and education experience lead to improvement (George and Cowan, 1999; Gibbs, 1993). Current UK practice relies largely on end of module questionnaires to feedback levels of student satisfaction (Cowan, 2002), however there are inherent weaknesses in this approach; it seldom leads to change for that particular cohort; it relies on uncorroborated opinion, and finally, it may derive from superficial feedback from a minority of students with the remainder suffering from questionnaire fatigue.

This research project involved a cohort of final year building surveying students at Sheffield Hallam University, in England, who were undertaking a dissertation in two modules. During 2002/3 the use of Blackboard software had also been adopted by the module leader as an educational tool to support student learning in the module. The lecturer wanted to identify how students used Blackboard and what they thought about the most appropriate use of the medium. The research methodology sought to redress some of the issues identified above with student feedback, regarding timing of feedback, implementation of change during the teaching period and the lack of depth in the data. Using principles adopted by Angelo and Cross (1993), this research formatively evaluated student perceptions and levels of satisfaction with the dissertation module, the teaching materials, the workshops, the supervisory arrangements and relationships. This paper presents the findings of the research and illustrates the changes that were made during the year and the student’s views of these changes. The paper demonstrates how linking teaching with research has been delivered at Sheffield Hallam.

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According to George and Cowan (1999) student feedback is essential to enable lecturers to understand whether attempts to improve learning and educational experience lead to improvement. Current UK practice uses end of module questionnaires to feedback levels of satisfaction (Cowan, 2002). There are inherent weaknesses, namely that it seldom leads to a change for that particular cohort of students, secondly it relies on uncorroborated opinion, and may derive from superficial feedback from a minority of students with the remainder suffering from questionnaire fatigue. Finally the data may not be especially relevant to a particular module, a particular weakness (Heywood, 2000).

Using principles identified by Angelo and Cross (1993), this research adopted a methodology to formatively evaluate student perceptions and levels of satisfaction with the dissertation module. Using a cohort of Building Surveying students at Sheffield Hallam University, in England, views on course materials, the use of Blackboard software, the workshops and the relationships with supervisors were gathered and analysed.

A number of measures were identified as a result of this study, that may, if implemented, improve student learning. Examples are the use of checklists for student for each research / dissertation stage to ensure nothing is forgotten. Provision of additional ‘drop in’ workshops where students could see the module leader with specific issues. Additional optional workshops for questionnaire coding and review of previous theses for example.

It will not be possible to measure whether this student cohort’s learning and performance improves until the summer of 2003 and the final dissertations are assessed. A statistical analysis, comparing their dissertation marks against marks for other topics will show whether there is improvement in marks as a result of this student feedback study. The 2002/3 cohort result can also be analysed against previous cohorts to establish whether any improvement is evident.

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The relationship between predisposing risk factors and precipitating life events of individuals presenting to an emergency department with Deliberate Self-Harm was investigated. Poor mental health and childhood abuse were related to suicide intent, only individuals' perceptions regarding their current life events were directly associated with lethality of the self-harm act. The portfolio illustrates the issues inherent in the treatment and management of schizophrenia and the potential of CBT in addressing symptoms and sequelae of acute psychosis. Four case studies are presented.

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Introduction : Although obesity is a modifiable risk factor for knee osteoarthritis (OA), the effect of weight gain on knee structure in young and healthy adults has not been examined. The aim of this study was to examine the relationship between body mass index (BMI), and change in BMI over the preceding 10-year period, and knee structure (cartilage defects, cartilage volume and bone marrow lesions (BMLs)) in a population-based sample of young to middle-aged females.

Methods :
One hundred and forty-two healthy, asymptomatic females (range 30 to 49 years) in the Barwon region of Australia, underwent magnetic resonance imaging (MRI) during 2006 to 2008. BMI measured 10 years prior (1994 to 1997), current BMI and change in BMI (accounting for baseline BMI) over this period, was assessed for an association with cartilage defects and volume, and BMLs.

Results :
After adjusting for age and tibial plateau area, the risk of BMLs was associated with every increase in one-unit of baseline BMI (OR 1.14 (95% CI 1.03 to 1.26) P = 0.009), current BMI (OR 1.13 (95% CI 1.04 to 1.23) P = 0.005), and per one unit increase in BMI (OR 1.14 (95% CI 1.03 to 1.26) P = 0.01). There was a trend for a one-unit increase in current BMI to be associated with increased risk of cartilage defects (OR 1.06 (95% CI 1.00 to 1.13) P = 0.05), and a suggestion that a one-unit increase in BMI over 10 years may be associated with reduced cartilage volume (-17.8 ml (95% CI -39.4 to 3.9] P = 0.10). Results remained similar after excluding those with osteophytes.

Conclusions :
This study provides longitudinal evidence for the importance of avoiding weight gain in women during early to middle adulthood as this is associated with increased risk of BMLs, and trend toward increased tibiofemoral cartilage defects. These changes have been shown to precede increased cartilage loss. Longitudinal studies will show whether avoiding weight gain in early adulthood may play an important role in diminishing the risk of knee OA.

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Lower socioeconomic status (SES) is associated with a higher prevalence of major risk factors for cardiovascular disease (CVD). However, few longitudinal studies have examined the association between SES and CVD risk factors over time. We aimed to determine whether SES, using education as a proxy, is associated with the onset of CVD risk factors over 5 years in an Australian adult cohort study.

Participants in the Australian Diabetes, Obesity and Lifestyle study (AusDiab) study aged 25 years and over who attended both baseline and 5-year follow-up examinations (n=5 967) were categorised according to educational attainment. Cardiovascular risk factor data at both time points were ascertained through questionnaire and physical measurement.

Women with lower education had a greater risk of progressing from normal weight to overweight or obesity than those with higher education (age-adjusted OR 1.57, 95% CI 1.06-2.31). Both men and women with lower education were more likely to develop diabetes (age-adjusted OR from higher education 1.75, 95% CI 1.14-2.71 and 3.01, 95% CI 1.26-7.20, respectively). A lower level of education was associated with a greater number of risk factors accumulated over time in women (OR of progressing from having two or less risk factors at baseline to three or more at follow up, 2.04, 95% 1.32-3.14).

In this Australian population-based study, lower educational attainment was associated with an increased risk of developing both individual and total CVD risk factors over a 5-year period. These findings suggest that SES inequalities in CVD will persist into the future.

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Cardiovascular disease (CVD) is the leading cause of death worldwide and originates in early life. The exact mechanisms of this early-life origin are unclear, but a likely mediator at the molecular level is epigenetic dysregulation of gene expression. Epigenetic factors have thus been posited as the likely drivers of early-life programming of adult-onset diseases. This review summarizes recent advances in epidemiology and epigenetic research of CVD risk in children, with a particular focus on twin studies. Classic twin studies enable partitioning of phenotypic variance within a population into additive genetic, shared, and nonshared environmental variances, and are invaluable in research in this area. Longitudinal cohort twin studies, in particular, may provide important insights into the role of epigenetics in the pathogenesis of CVD. We describe candidate gene and epigenome-wide association studies (EWASs) and transgenerational epigenetic inheritance of CVD, and discuss the potential for evidence-based interventions. Identifying epigenetic changes associated with CVD-risk biomarkers in children will provide new opportunities to unravel the underlying biological mechanism of the origins of CVD and enable identification of those at risk for early-life interventions to alter the risk trajectory and potentially reduce CVD incidence later in life.

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BACKGROUND: The efficacy of clozapine for the treatment of schizophrenia has been demonstrated. However, a range of adverse events have been associated with its use. To date, there remains a paucity of data regarding the prevalence of clozapine-induced cardiovascular (CV) and parameters associated with the development of metabolic syndrome, alongside associated risk factors for their development. METHODS: An observational, clinical cohort study design of 355 clozapine patients who were enrolled in the Barwon Health Clozapine Program at Geelong Hospital, Victoria, Australia, between 2008-12. Medical records were accessed retrospectively. Multivariate logistic regression was used to determine associations with adverse event(s). RESULTS: Older age of commencement with clozapine was consistently associated with increased risk of CV abnormalities, with the exception of tachycardia where older age was protective (Odds Ratio [OR]: 0.97; 95% Confidence Intervals [CI]: 0.95, 0.99). Males had significantly greater odds of most metabolic disturbances with the exception of being obese (BMI: ≥30 OR: 0.45; 95% CIs: 0.24, 0.85). Older age of commencement was a significantly associated variable with High- Density Lipoprotein-cholesterol (OR: 1.03; 95% CIs: 1.01, 1.07) and fasting glucose (OR:1.04; 95% CIs: 1.02, 1.07). An increase in BMI was consistently and significantly associated with all metabolic events. CONCLUSION: Male patients who are obese at any point during treatment and older at treatment commencement may be the most vulnerable to adverse CV and metabolic events. While future studies using a matched case-control design may be required to verify these findings, we recommend that treating clinicians consider these risks when assessing patient suitability to clozapine therapy.

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BACKGROUND: Most studies describing vaginal Candida spp. in pregnancy focus on symptomatic vaginitis, rather than asymptomatic colonisation, and solely utilise microbiological culture. The extent to which asymptomatic vaginal carriage may represent a reservoir for infant oral colonisation has been highly debated. MATERIALS AND METHODS: This study formed part of the Candida and Staphylococcus Transmission Longitudinal Evaluation (CASTLE) study, in Melbourne, Australia, from 2009 to 2011 and used culture and molecular methods to examine vaginal swabs collected late in the third trimester of pregnancy for Candida spp. Oral swabs from infants were also examined using culture methods. RESULTS: Overall, 80 of 356 (22%) women were positive for Candida spp; the majority being Candida albicans (83%). Candida glabrata and other Candida spp. were also identified, but in much lower numbers. Molecular analysis identified numerous positive samples not detected by culture, including 13 cases of C. albicans. In addition, some positive samples only recorded to genus level by culture were accurately identified as either C. albicans or C. glabrata following molecular analyses. Eighteen infants recorded positive Candida spp. cultures, predominantly C. albicans. However, there were only four (25%) mother/infant dyads where C. albicans was detected. CONCLUSIONS: This study provides valuable data on asymptomatic colonisation rates of Candida spp. within an asymptomatic population of women late in pregnancy. The utilisation of molecular methods improved the rate of detection and provided a more accurate means for identification of non-albicans Candida spp. The low mother/infant colonisation rate suggests that non-maternal sources are likely involved in determining infant oral colonisation status.

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BACKGROUND: Analyses of longitudinal health-related quality of life data often exclude participants who die, which limits the generalizability of the results. Methods to incorporate death as a valid score in the Medical Outcomes Study Short-Form (SF-36) have been suggested but need to be evaluated in other populations. OBJECTIVES: We sought to apply a method of transforming the SF-36 Physical Component Score (PCS) to include death. A transformation to estimate the probability of being "healthy" in 3 years, based on the current PCS value, will be developed and validated. SUBJECTS: Women in the Australian Longitudinal Study on Women's Health (ALSWH), ages 70-75 years at Survey 1 in 1996 (n = 12,432), were followed-up at 3 yearly intervals for 6 years. RESULTS: The transformation derived from the ALSWH data provides evidence that the methodology for transforming the PCS to account for deaths is sound. The 3-year equation provided good estimates of the probability of being healthy in 3 years and the method allowed deaths to be included in an analysis of changes in health over time. CONCLUSIONS: For longitudinal studies involving the SF-36 in which subjects have died, we support the recommendation that both the PCS and its transformed value which includes deaths should be analyzed to examine the influence of deaths on the study conclusions. Using study data to derive empirical parameters for the transformations may be appropriate for studies with follow-up intervals of other lengths.

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AIM: To establish 1) the socioeconomic and cultural profile and 2) correlates of quality of life (QOL) of Maori in advanced age. METHOD: A cross sectional survey of a population based cohort of Maori aged 80-90 years, participants in LiLACS NZ, in the Rotorua and Bay of Plenty region of New Zealand. Socioeconomic and cultural engagement characteristics were established by personal interview and QOL was assessed by the SF-12. RESULTS: In total 421 (56%) participated and 267 (63%) completed the comprehensive interview. Maori lived with high deprivation areas and had received a poor education in the public system. Home ownership was high (81%), 64% had more than 3 children still living and social support was present for practical tasks and emotional support in 82%. A need for more practical help was reported by 21%. Fifty-two percent of the participants used te reo Maori me nga tikanga (Maori language and culture) daily. One in five had experienced discrimination and one in five reported colonisation affecting their life today. Greater frequency of visits to marae/sacred gathering places was associated with higher physical health-related QOL. Unmet need for practical help was associated with lower physical health-related QOL. Lower mental health-related QOL was associated with having experienced discrimination. CONCLUSION: Greater language and cultural engagement is associated with higher QOL for older Maori and unmet social needs and discrimination are associated with lower QOL.