Prevalence of age-related macular degeneration in the Republic of Ireland

Abstract Background Age-related macular degeneration (AMD) remains the most common cause of visual loss among subjects over 50 years of age in the developed world. The Irish Longitudinal study on Ageing (TILDA) is a population-based study of subjects aged 50 years or older, designed to investigate factors that influence ageing, and has enabled this investigation of the prevalence of AMD in the Republic of Ireland (ROI). Methods Data collected from a nationally representative sample of community-living older adults aged 50 years and over in ROI over the period November 2009 to July 2011. 5035 participants attended the TILDA health centre for assessment. Retinal photographs were obtained in 4859 of these participants. Retinal grading was performed in a masked fashion using a modified version of the International Classification and Grading System for AMD. Results Adjusting for lower response rates among older subjects, the estimated overall prevalence of any AMD was 7.2% (95% CI 6.5% to 7.9%) in the population aged 50 years or older. The estimated prevalence of early AMD was 6.6% (95% CI 5.9% to 7.3%), and the estimated prevalence of late AMD was 0.6% (95% CI 0.4% to 0.8%). Statistically significant associations with AMD included increasing age and family history of the condition. Conclusions This is the first study to provide prevalence estimates of AMD in ROI and will inform eye care professionals and policymakers involved in the delivery and planning of care for those afflicted with this condition

Younger age as a prognostic indicator in breast cancer: A cohort study

<p>Abstract</p> <p>Background</p> <p>The debate continues as to whether younger women who present with breast cancer have a more aggressive form of disease and a worse prognosis. The objectives of this study were to determine the incidence of breast cancer in women under 40 years old and to analyse the clinicopathological characteristics and outcome compared to an older patient cohort.</p> <p>Methods</p> <p>Data was acquired from a review of charts and the prospectively reviewed GUH Department of Surgery database. Included in the study were 276 women diagnosed with breast cancer under the age of forty and 2869 women over forty. For survival analysis each women less than 40 was matched with two women over forty for both disease stage and grade.</p> <p>Results</p> <p>The proportion of women diagnosed with breast cancer under the age of forty in our cohort was 8.8%. In comparison to their older counterparts, those under forty had a higher tumour grade (p = 0.044) and stage (p = 0.046), a lower incidence of lobular tumours (p < 0.001), higher estrogen receptor negativity (p < 0.001) and higher <it>HER2 </it>over-expression (p = 0.002); there was no statistical difference as regards tumour size (p = 0.477). There was no significant difference in overall survival (OS) for both groups; and factors like tumour size (p = 0.026), invasion (p = 0.026) and histological type (p = 0.027), PR (p = 0.031) and <it>HER2 </it>(p = 0.002) status and treatment received were independent predictors of OS</p> <p>Conclusion</p> <p>Breast cancer in younger women has distinct histopathological characteristics; however, this does not result in a reduced survival in this population.</p

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Observational studies, matching and propensity scores: Applied to colorectal cancer data

Many studies in biostatistics are concerned with comparing two groups of patients, a treatment and a control group, to determine the effect of the treatment. Observational studies typically make use of available data, such as from a cancer registry, and consequently lack explicit design and randomisation which makes analysis and the drawing of definitive conclusions difficult. One potential problem is that there are often large imbalances in the distributions of covariates across the treatment groups. In a randomised control trial, this imbalance in the distribution of observed covariates would usually be accounted for in the design of a study and randomisation would balance over the observed and unobserved covariates. However, when the data comes from an observational study, this imbalance affects subsequent analysis and usual statistical methods are often not enough to correct for this imbalance, leading to biased estimates of treatment effects. First, we discuss the use of observational studies and randomised control trials, contrasting and comparing them. Following this, methods to allow observational studies to be analysed in a meaningful and correct manner are presented, including matching and inverse probability weighting. However, when there is an extreme imbalance in the sizes of the treatment and control groups these methods seem to perform unreliably. We consider the use of methods, both existing ones from the literature and newly developed proposals, to overcome this deterioration in performance. We attempt to quantify the point at which the degree of imbalance in the numbers over the two groups causes serious deterioration. The various methods, existing and newly proposed, are compared using a simulation study to evaluate their performance. Throughout, the ideas are illustrated in a survival analysis setting for a study examining the effect of inflammatory bowel disease on survival in colorectal cancer patients, using data from a cancer registry.2022-04-1

Observational studies, matching and propensity scores: Applied to colorectal cancer data

Many studies in biostatistics are concerned with comparing two groups of patients, a treatment and a control group, to determine the effect of the treatment. Observational studies typically make use of available data, such as from a cancer registry, and consequently lack explicit design and randomisation which makes analysis and the drawing of definitive conclusions difficult. One potential problem is that there are often large imbalances in the distributions of covariates across the treatment groups. In a randomised control trial, this imbalance in the distribution of observed covariates would usually be accounted for in the design of a study and randomisation would balance over the observed and unobserved covariates. However, when the data comes from an observational study, this imbalance affects subsequent analysis and usual statistical methods are often not enough to correct for this imbalance, leading to biased estimates of treatment effects. First, we discuss the use of observational studies and randomised control trials, contrasting and comparing them. Following this, methods to allow observational studies to be analysed in a meaningful and correct manner are presented, including matching and inverse probability weighting. However, when there is an extreme imbalance in the sizes of the treatment and control groups these methods seem to perform unreliably. We consider the use of methods, both existing ones from the literature and newly developed proposals, to overcome this deterioration in performance. We attempt to quantify the point at which the degree of imbalance in the numbers over the two groups causes serious deterioration. The various methods, existing and newly proposed, are compared using a simulation study to evaluate their performance. Throughout, the ideas are illustrated in a survival analysis setting for a study examining the effect of inflammatory bowel disease on survival in colorectal cancer patients, using data from a cancer registry.2022-04-1

Analysis of an Observational Study

The study presented below aimed to compare survival of colorectal cancer patients against survival of a sub-population with a secondary disease, in ammatory bowel disease (IBD). The data were taken from a observational study, that is there was no explicit design. The study had many complications, but the most significant aspect was that the number of controls was much greater than the number of cases of interest. Some techniques are used to overcome these obstacles, including: matching of the dataset, to make the controls and cases as similar as possible at time of diagnosis, effectively retrospectively fi tting a design; weighting of the data, using both the propensity score and the number of similar patients found in matching

Analysis of an Observational Studies - An Example Using Data from the Irish Cancer Registry

The study presented below aimed to compare survival of colorectal cancer patients against survival of a sub-population with a secondary disease, in ammatory bowel disease (IBD). The data were taken from a observational study, that is there was no explicit design. The study had many complications, but the most signi cant aspect was that the number of controls was much greater than the number of cases of interest. Some techniques are used to overcome these obstacles, including: matching of the dataset, to make the controls and cases as similar as possible at time of diagnosis, e ectively retrospectively tting a design; weighting of the data, using both the propensity score and the number of similar patients found in matching

Income and wealth in the Irish longitudinal study on ageing

Between 2009 and 2011, data were collected under the first wave of The Irish Longitudinal Study on Ageing (TILDA). Over 8,500 people aged 50 and over and living in Ireland were interviewed about a wide range of topics covering socio-economic and health issues. Our primary goals in this paper are to present details on two of the variables which will be of particular interest to economists, namely income and wealth, and to discuss issues in relation to their use. We describe how the income and wealth data were collected. We assess the quality of the income data by comparing them to those obtained through the European Union Survey on Income and Living Conditions (EU-SILC). We examine the joint distribution of income and assets and conduct a small exercise on using the data to design a means-testing system