Foot-and-Mouth Disease control costs compared: An Irish case study.

The primary objective of this paper is to evaluate alternative control strategies for a number of simulated outbreaks of Foot-and-Mouth Disease (FMD) in four agriculturally diverse Irish regions, examining for the first time, the potential role of emergency vaccination in the country. The recent EU Directive (2003/85/EC) on FMD control permits the use of emergency vaccination as part of an FMD control strategy. While the slaughter of infected animals and dangerous contacts (susceptible animals on epidemiologically linked holdings) remains the principal tool for tackling an outbreak, the potential use of vaccination as an adjunct to the basic culling policy is now being considered. Using an integrated approach, combining epidemiological and economic modules, the alternatives of stamping-out both alone and in conjunction with emergency vaccination are examined using hypothetical outbreaks and their control costs compared. Overall, it cannot be said, a priori, that one control option is better than the other. Choice of control strategy would appear to be highly dependent on herd density, production type and other region specific issues. This analysis has focused on control costs only; taking wider economy costs into account may however change this overall conclusion.Foot-and-Mouth disease, alternative control strategies, transboundary animal diseases, emergency vaccination, Livestock Production/Industries, Q1, Q17, Q58,

Time trends in neuropathology give clues to dementia risk reduction

A new study sheds light on the declining incidence of dementia by examining trends in neuropathology over time in autopsy results from two large US cohorts. Although the prevalence of neurodegenerative pathologies remained similar, a reduction in the prevalence of vascular pathologies over time suggests that improvements in both cardiovascular health and cognitive reserve have helped to reduce dementia risk

Community environment, cognitive impairment and dementia in later life: results from the Cognitive Function and Ageing Study

Background: Few studies have investigated the impact of the community environment, as distinct from area deprivation, on cognition in later life. This study explores cross-sectional associations between cognitive impairment and dementia and environmental features at the community level in older people. Method: The postcodes of the 2424 participants in the year-10 interview of the Cognitive Function and Ageing Study in England were mapped into small area level geographical units (Lower-layer Super Output Areas) and linked to environmental data in government statistics. Multilevel logistic regression was conducted to investigate associations between cognitive impairment (defined as MMSE3 in GMS-AGECAT) and community level measurements including area deprivation, natural environment, land use mix and crime. Sensitivity analyses tested the impact of people moving residence within the last two years. Results: Higher levels of area deprivation and crime were not significantly associated with cognitive impairment and dementia after accounting for individual level factors. Living in areas with high land use mix was significantly associated with a nearly 60% reduced odds of dementia (OR: 0.4; 95% CI: 0.2, 0.8) after adjusting for individual level factors and area deprivation, but there was no linear trend for cognitive impairment. Increased odds of dementia (OR: 2.2, 95% CI: 1.2, 4.2) and cognitive impairment (OR: 1.4, 95% CI: 1.0, 2.0) were found in the highest quartile of natural environment availability. Findings were robust to exclusion of the recently relocated. Conclusion: Features of land use have complex associations with cognitive impairment and dementia. Further investigations should focus on environmental influences on cognition to inform health and social policies

A comparison of parametric models for the investigation of the shape of cognitive change in the older population.

BACKGROUND: Cognitive decline is a major threat to well being in later life. Change scores and regression based models have often been used for its investigation. Most methods used to describe cognitive decline assume individuals lose their cognitive abilities at a constant rate with time. The investigation of the parametric curve that best describes the process has been prevented by restrictions imposed by study design limitations and methodological considerations. We propose a comparison of parametric shapes that could be considered to describe the process of cognitive decline in late life. Attrition plays a key role in the generation of missing observations in longitudinal studies of older persons. As ignoring missing observations will produce biased results and previous studies point to the important effect of the last observed cognitive score on the probability of dropout, we propose modelling both mechanisms jointly to account for these two considerations in the model likelihood. METHODS: Data from four interview waves of a population based longitudinal study of the older population, the Cambridge City over 75 Cohort Study were used. Within a selection model process, latent growth models combined with a logistic regression model for the missing data mechanism were fitted. To illustrate advantages of the model proposed, a sensitivity analysis of the missing data assumptions was conducted. RESULTS: Results showed that a quadratic curve describes cognitive decline best. Significant heterogeneity between individuals about mean curve parameters was identified. At all interviews, MMSE scores before dropout were significantly lower than those who remained in the study. Individuals with good functional ability were found to be less likely to dropout, as were women and younger persons in later stages of the study. CONCLUSION: The combination of a latent growth model with a model for the missing data has permitted to make use of all available data and quantify the effect of significant predictors of dropout on the dropout and observational processes. Cognitive decline over time in older persons is often modelled as a linear process, though we have presented other parametric curves that may be considered.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Prevalence of dementia in East Asia: a synthetic review of time trends.

OBJECTIVE: This study aims to synthesise evidence on time trends of dementia prevalence in East Asian countries including Japan, China, South Korea and Taiwan and assess the impact of the societal changes on future prevalence. METHOD: Relevant reviews and recent nationwide studies in East Asia were identified to investigate changes in prevalence of dementia over time taking into account the potential impact of methodological factors and study designs. RESULTS: The robust evidence that has been interpreted to suggest a substantial increasing trend over time is less compelling once fundamental differences in study methods and populations across individual surveys are considered. In Japan, longitudinal studies in small areas suggest the potential increase of prevalence after 2000. Increasing trends in China, South Korea and Taiwan over the last 20-30 years are based on the literature review without adjustment for methodological differences. Economic development and huge societal changes alongside the rise of non-communicable disease in East Asia could lead to increasing prevalence of dementia in the future once those cohorts with high risk of dementia reached their older age. CONCLUSION: Current evidence is not sufficient to suggest increasing trends of dementia prevalence in East Asia. Longitudinal studies with representative samples and stable methodology are needed to provide fundamental information of the epidemiology of dementia and identify important risk factors in East Asian societies.There is no specific funding contributing to this study. Yu-Tzu Wu received a PhD scholarship from the Cambridge Trust, University of Cambridge. Fiona E. Matthews was supported by the Medical Research Council [grant number U105292687].This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1002/gps.4297/abstract

Dementia: time trends and policy responses.

In recent years, dementia has been considered a public health priority and become a topic of major political interest. Recent reviews and studies have reported with varying degrees of alarm an impending and existing "dementia epidemic" with increasing predicted trends in prevalence and enormous numbers of people with dementia particularly in low- and middle-income countries (LMICs). However, robust evidence from dementia research in high-income countries suggests stable or decreased prevalence over the last decades. Current evidence is not sufficient to suggest increasing trends of prevalence in LMICs once variation in methodological factors and study populations are taken into account. Changes in diagnostic methods over the last decades substantially influence the identification of dementia cases with systematic difference between the resulting individual prevalence studies. Potential geographical variations at the country level might indicate potential risk factors at population levels or systematic difference in clinical application of dementia diagnosis. Although it is important and necessary to use information from dementia research for evidence-based policymaking, over-interpretation of results without carefully considering underlying factors could exaggerate the findings and influence policy planning in ways which do not serve current and future population best. Planning of dementia policy needs to take full cognisance of the provenance of the data being used and be integrated with policies which optimise health across the lifecourse.Yu-Tzu Wu received a PhD scholarship from the Cambridge Trust, University of Cambridge. Fiona E. Matthews was supported by the Medical Research Council [grant number U105292687].This is the accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.maturitas.2014.06.02

Community environment, cognitive impairment and dementia in later life: results from the Cognitive Function and Ageing Study

Background: Few studies have investigated the impact of the community environment, as distinct from area deprivation, on cognition in later life. This study explores cross-sectional associations between cognitive impairment and dementia and environmental features at the community level in older people. Method: The postcodes of the 2424 participants in the year-10 interview of the Cognitive Function and Ageing Study in England were mapped into small area level geographical units (Lower-layer Super Output Areas) and linked to environmental data in government statistics. Multilevel logistic regression was conducted to investigate associations between cognitive impairment (defined as MMSE3 in GMS-AGECAT) and community level measurements including area deprivation, natural environment, land use mix and crime. Sensitivity analyses tested the impact of people moving residence within the last two years. Results: Higher levels of area deprivation and crime were not significantly associated with cognitive impairment and dementia after accounting for individual level factors. Living in areas with high land use mix was significantly associated with a nearly 60% reduced odds of dementia (OR: 0.4; 95% CI: 0.2, 0.8) after adjusting for individual level factors and area deprivation, but there was no linear trend for cognitive impairment. Increased odds of dementia (OR: 2.2, 95% CI: 1.2, 4.2) and cognitive impairment (OR: 1.4, 95% CI: 1.0, 2.0) were found in the highest quartile of natural environment availability. Findings were robust to exclusion of the recently relocated. Conclusion: Features of land use have complex associations with cognitive impairment and dementia. Further investigations should focus on environmental influences on cognition to inform health and social policies