74 resultados para Prospective Studies

em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


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Purpose: Researchers have demonstrated associations between trauma and psychosis. Childhood trauma, in particular, appears to be an important determinant. Recently, bullying has become considered a traumatic experience in its own right. This review aims to analyse research with prospective designs, which will enable conclusions about whether or not bullying causes psychosis.

Methods: A systematic review of the literature was carried out independently by two reviewers. Eligibility and quality assessment criteria were applied. A meta-analysis and narrative synthesis were then completed.

Results: Ten studies met inclusion criteria. Four used data from the same large database, and were combined as one. The majority provided confirmation that bullying appears to cause later development of psychosis. A meta-analysis yielded an unadjusted odds ratio (OR) of 2.148 [95% confidence interval (CI) 1.140–4.044].

Conclusions: The studies reviewed here suggest that bullying does predict the later development of psychotic symptoms. What is lacking from the literature is adequate investigation into other potential mediating factors. The current review highlights the significant role of bullying within this complex interaction. Potential mediating variables are explored, including a dose–response effect for the severity and frequency of victimization. Suggestions for targeting intervention are also suggested alongside clinical implications and recommendations for future research.

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Objectives: We sought to replicate the association between the kinesin-like protein 6 (KIF6) Trp719Arg polymorphism (rs20455), and clinical coronary artery disease (CAD).
Background: Recent prospective studies suggest that carriers of the 719Arg allele in KIF6 are at increased risk of clinical CAD compared with noncarriers.
Methods: The KIF6 Trp719Arg polymorphism (rs20455) was genotyped in 19 case-control studies of nonfatal CAD either as part of a genome-wide association study or in a formal attempt to replicate the initial positive reports.
Results: A total of 17,000 cases and 39,369 controls of European descent as well as a modest number of South Asians, African Americans, Hispanics, East Asians, and admixed cases and controls were successfully genotyped. None of the 19 studies demonstrated an increased risk of CAD in carriers of the 719Arg allele compared with noncarriers. Regression analyses and fixed-effects meta-analyses ruled out with high degree of confidence an increase of <2% in the risk of CAD among European 719Arg carriers. We also observed no increase in the risk of CAD among 719Arg carriers in the subset of Europeans with early-onset disease (younger than 50 years of age for men and younger than 60 years of age for women) compared with similarly aged controls as well as all non-European subgroups.
Conclusions: The KIF6 Trp719Arg polymorphism was not associated with the risk of clinical CAD in this large replication study.

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Background Prospective studies on the relationship between organisational merger and mental health have been conducted using subjective health indicators. The objective of this prospective occupational cohort study was to examine whether a negative change during an organisational merger is an independent predictive factor of psychiatric morbidity.

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Background Most prospective studies on the relationship between sense of coherence (SOC) and mental health have been conducted using subjective health indicators and short-term follow-ups. The objective of this prospective occupational cohort study was to examine whether a strong sense of coherence is a protective factor against psychiatric disorders over a long period of time.

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Context: In nondiabetic pregnancy, cross-sectional studies have shown associations between maternal dyslipidemia and preeclampsia (PE). In type 1 diabetes mellitus (T1DM), the prevalence of PE is increased 4-fold, but prospective associations with plasma lipoproteins are unknown.

Objectives: The aim of this study was to define lipoprotein-related markers and potential mechanisms for PE in T1DM.

Design and Settings: We conducted a multicenter prospective study in T1DM pregnancy.

Patients: We studied 118 T1DM women (26 developed PE, 92 remained normotensive). Subjects were studied at three visits before PE onset [12.2 1.9, 21.6 1.5, and 31.5 1.7 wk gestation (means SD)] and at term (37.6 2.0 wk). Nondiabetic normotensive pregnant women (n 21) were included for reference.

Main Outcome Measures: Conventional lipid profiles, lipoprotein subclasses [defined by size (nuclear magnetic resonance) and by apolipoprotein content], serum apolipoproteins (ApoAI, ApoB, and ApoCIII), and lipolysis (ApoCIII ratio) were measured in T1DM women with and without subsequent PE.

Results: In women with vs. without subsequent PE, at the first and/or second study visits: lowdensity lipoprotein (LDL)-cholesterol, particle concentrations of total LDL and large (but not small) LDL, serum ApoB, and ApoB:ApoAI ratio were all increased (P 0.05); peripheral lipoprotein lipolysis was decreased (P0.01). These early differences remained significant in covariate analysis (glycated hemoglobin, actual prandial status, gravidity, body mass index, and diabetes duration) but were not present at the third study visit. High-density lipoprotein and very low-density lipoprotein subclasses did not differ between groups before PE onset.

Conclusions: Early in pregnancy, increased cholesterol-rich lipoproteins and an index suggesting decreased peripheral lipolysis were associated with subsequent PE in T1DM women. Background maternal lipoprotein characteristics, perhaps masked by effects of late pregnancy, may influence PE risk.

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Objective: The incidence of oesophageal adenocarcinoma (EAC) has increased rapidly over the past 40 years and accumulating evidence suggests that obesity, as measured by body mass index (BMI), is a major risk factor. It remains unclear whether abdominal obesity is associated with EAC and gastric adenocarcinoma.

Design: Cox proportional hazards regression was used to examine associations between overall and abdominal obesity with EAC and gastric adenocarcinoma among 218 854 participants in the prospective NIHeAARP cohort.

Results: 253 incident EAC, 191 gastric cardia adenocarcinomas and 125 gastric non-cardia adenocarcinomas accrued to the cohort. Overall obesity (BMI) was positively associated with EAC and gastric
cardia adenocarcinoma risk (highest ($35 kg/m2) vs referent (18.5e<25 kg/m2); HR 2.11, 95% CI 1.09 to 4.09 and HR 3.67, 95% CI 2.00 to 6.71, respectively). Waist circumference was also positively associated with EAC and gastric cardia adenocarcinoma risk (highest vs referent; HR 2.01, 95% CI 1.35 to 3.00 and HR 2.22, 95% CI 1.43 to 3.47, respectively), whereas waist-to-hip ratio (WHR) was positively associated with EAC risk only (highest vs referent; HR 1.81, 95% CI 1.24 to 2.64) and persisted in patients with normal BMI (18.5e<25 kg/m2). Mutual adjustment of WHR and BMI attenuated
both, but did not eliminate the positive associations for either with risk of EAC. In contrast, the majority of the anthropometric variables were not associated with adenocarcinomas of the gastric non-cardia.

Conclusion Overall obesity was associated with a higher risk of EAC and gastric cardia adenocarcinoma, whereas abdominal obesity was found to be associated with increased EAC risk; even in people with normal BMI

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Obesity has consistently been linked to an increased risk of colorectal cancer, particularly among men. Whether body mass index (BMI) differentially influences the risk across the stages of colorectal cancer development remains unclear. We evaluated the associations of BMI with colorectal adenoma incidence, adenoma recurrence, and cancer in the context of a large screening trial, in which cases and controls had an equal chance for disease detection.

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PURPOSE. To investigate the methods used in contemporary ophthalmic literature to designate visual acuity (VA). METHODS. Papers in all 2005 editions of five ophthalmic journals were considered. Papers were included if (1) VA, vision, or visual function was mentioned in the abstract and (2) if the study involved age-related macular degeneration, cataract, or refractive surgery. If a paper was selected on the basis of its abstract, the full text of the paper was examined for information on the method of refractive correction during VA testing, type of chart used to measure VA, specifics concerning chart features, testing protocols, and data analysis and means of expressing VA in results. RESULTS. One hundred twenty-eight papers were included. The most common type of charts used were described as logMAR-based. Although most (89.8%) of the studies reported on the method of refractive correction during VA testing, only 58.6% gave the chart design, and less than 12% gave any information whatsoever on chart features or measurement procedures used. CONCLUSIONS. The methods used and the approach to analysis were rarely described in sufficient detail to allow others to replicate the study being reported. Sufficient detail should be given on VA measurement to enable others to duplicate the research. The authors suggest that charts adhering to Bailey-Lovie design principles always be used to measure vision in prospective studies and their use encouraged in clinical settings. The distinction between the terms logMAR, an acuity notation, and Bailey-Lovie or ETDRS as chart types should be adhered to more strictly. Copyright © Association for Research in Vision and Ophthalmology.

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DietCompLyf is a multi-centre prospective study designed to investigate associations between phytoestrogens - naturally occurring plant compounds with oestrogenic properties - and other diet and lifestyle factors with breast cancer recurrence and survival. 3159 women with grades I-III breast cancer were recruited 9-15 months post-diagnosis from 56 UK hospitals. Detailed information on clinico-pathological, diet, lifestyle and quality of life is collected annually up to 5 years. Biological samples have also been collected as a resource for subsequent evaluation. The characteristics of the patients and associations between pre-diagnosis intake of phytoestrogens (isoflavones and lignans; assessed using the EPIC-Norfolk UK 130 question food frequency questionnaire) and breast cancer (i) risk factors and (ii) prognostic factors are described for 1797 women who had complete data for all covariates and phytoestrogens of interest. Isoflavone intakes were higher in the patients who were younger at diagnosis, in the non-smokers, those who had breast-fed and those who took supplements. Lignan intakes were higher in patients with a higher age at diagnosis, in ex-smokers, those who had breast-fed, who took supplements, had a lower BMI at diagnosis, lower age at menarche and were nulliparous. No significant associations between pre-diagnosis phytoestrogen intake and factors associated with improved breast cancer prognosis were observed. The potential for further exploration of the relationship between phytoestrogens and breast cancer recurrence and survival, and for the establishment of evidence to improve dietary and lifestyle advice offered to patients following breast cancer diagnosis using DietCompLyf data is discussed.

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Objective To demonstrate the potential value of screening for Down's Syndrome using highly correlated repeated measures of serum markers taken in the first and second trimesters of pregnancy. Design A Monte Carlo simulation study. Population Detection rates and false positive rates relating to the maternal age distribution of England and Wales for the period 1996 to 1998 were obtained using marker distributions from the SURUSS study. Results Screening using first trimester nuchal translucency and repeated measures of uE3 and PAPP-A in the first and second trimester has an estimated false positive rate of 0.3% for an 85% detection rate. This should be compared with the integrated test with an estimated false positive rate of 1.2% for the same detection rate. Conclusionsâ?? The performance of repeated measures screening tests, and their acceptability to women, should be assessed in further prospective studies.

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Objective To present a first and second trimester Down syndrome screening strategy, whereby second-trimester marker determination is contingent on the first-trimester results. Unlike non-disclosure sequential screening (the Integrated test), which requires all women to have markers in both trimesters, this allows a large proportion of the women to complete screening in the first trimester. Methods Two first-trimester risk cut-offs defined three types of results: positive and referred for early diagnosis; negative with screening complete; and intermediate, needing second-trimester markers. Multivariate Gaussian modelling with Monte Carlo simulation was used to estimate the false-positive rate for a fixed 85% detection rate. The false-positive rate was evaluated for various early detection rates and early test completion rates. Model parameters were taken from the SURUSS trial. Results Completion of screening in the first trimester for 75% of women resulted in a 30% early detection rate and a 55% second trimester detected rate (net 85%) with a false-positive rate only 0.1% above that achievable by the Integrated test. The screen-positive rate was 0.1% in the first trimester and 4.7% for those continuing to be tested in the second trimester. If the early detection rate were to be increased to 45% or the early completion rate were to be increased to 80%, there would be a further 0.1% increase in the false-positive rate. Conclusion Contingent screening can achieve results comparable with the Integrated test but with earlier completion of screening for most women. Both strategies need to be evaluated in large-scale prospective studies particularly in relation to psychological impact and practicability.

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Objective To demonstrate the potential value of three-stage sequential screening for Down syndrome. Methods Protocols were considered in which maternal serum pregnancy associated plasma protein-A (PAPP-A) and free -human chorionic gonadotropin (hCG) measurements were taken on all women in the first trimester. Those women with very low Down syndrome risks were screened negative at that stage and nuchal translucency (NT) was measured on the remainder and the risk reassessed. Those with very low risk were then screened negative and those with very high risk were offered early diagnostic testing. Those with intermediate risks received second-trimester maternal serum -fetoprotein, free -hCG, unconjugated estriol and inhibin-A. Risk was then reassessed and those with high risk were offered diagnosis. Detection rates and false-positive rates were estimated by multivariate Gaussian modelling using Monte-Carlo simulation. Results The modelling suggests that, with full adherence to a three-stage policy, overall detection rates of nearly 90% and false-positive rates below 2.0% can be achieved. Approximately two-thirds of pregnancies are screened on the basis of first-trimester biochemistry alone, five out of six women complete their screening in the first trimester, and the first-trimester detection rate is over 60%. Conclusion Three-stage contingent sequential screening is potentially highly effective for Down syndrome screening. The acceptability of this protocol and its performance in practice, should be tested in prospective studies. Copyright © 2006 John Wiley & Sons, Ltd.