Estimating Attributable Life Expectancy Under the Proportional Mean Residual Life Model

In population-based health research, the so-called population attributable fraction is an important quantity that calculates the percentage of excess risk of morbidity and mortality associated with modifiable risk factors for a given population. While the concept of “risk” is usually measured by event probabilities, in practice it may be of a more direct interest to know the excess life expectancy associated with the modifiable risk factors instead, particularly when mortality is of the ultimate concern. In this paper, we thus propose to study a novel quantity, termed “attributable life expectancy,” to measure the population attributable fraction of life expectancy. We further develop a model-based approach for the attributable life expectancy under the Oakes–Dasu proportional mean residual life model, and establish its asymptotic properties for inferences. Numerical studies that include Monte-Carlo simulations and an actual analysis of the mortality associated with smoking cessation in an Asia Cohort Consortium are conducted to evaluate the performance of our proposed method.

     

A study of the prosthodontic and oral health needs of an ageing psychiatric population

Background: Life expectancy has increased worldwide, with India (having 8% who are senior citizens), falling into the “Greying Country” category. This ageing population constitutes a high‐risk oral health group, vis‐à‐vis impaired manual dexterity, cognitive deterioration and unmet treatment needs, which could be compounded by psychiatric morbidity. Objective: To assess oral health status and prosthodontic need of ageing psychiatric patients. Materials and method: One hundred and twenty‐five patients, aged 50 years or above, admitted to the Department of Geriatric Mental Health, King George’s Medical University, Lucknow, Uttar Pradesh, India, were examined for prosthodontic, oral health status and need, the study population being divided into groups on the basis of Bristol Activities Scale of Daily Living. Results: Depressive symptoms (which increased with age) and psychiatric morbidity were found to be more in females. About 98% of the population showed probing depths of more than 3 mm, with mean number of decayed/missing teeth and inability to maintain oral/denture hygiene (p < 0.001) increasing in higher disability levels. While 91.3% of the population wearing a prosthesis required new dentures, 33.3% of the study population had unfulfilled partial denture need and 28.4% had unfulfilled upper/lower complete denture need. Conclusion: Ageing psychiatric subjects require dental education and treatment to meet their needs.     

Prevention. How much harm? How much benefit? 1. Influence of reporting methods on perception of benefits.

Before a physician or a patient can decide whether a preventive program is worth while, each must understand the nature and degree of its benefits and the frequency and magnitude of its adverse effects. Preventive interventions can be divided into two major categories: those with infrequent or minor adverse effects and those with adverse effects that are frequent or serious. Accident prevention, avoidance of high-risk behaviour and healthy lifestyle choices such as breast-feeding and moderate exercise are associated with few adverse consequences. By contrast, screening populations for disease, risk classification for the purpose of selective preventive interventions, dietary intervention and prophylactic drug treatment may lead to more frequent and serious adverse effects. When assessing whether the benefits of a preventive intervention outweigh the harm, one must be aware that the methods used to report benefits of clinical trials may distort the reader''s perception of their magnitude. The relative reduction of morbidity or mortality rate often grossly exaggerates benefits and should never be used as a basis for clinical decision making. More realistic ways of recording benefits are the absolute reduction of morbidity or mortality rate, the number of patients that need to be treated to avoid one adverse event, and the total cohort mortality rate.     

Effects of d‐galactose‐induced ageing on the heart and its potential interventions

Ageing is a strong independent risk factor for disability, morbidity and mortality. Post‐mitotic cells including those in the heart are a particular risk to age‐related deterioration. As the occurrence of heart disease is increasing rapidly with an ageing population, knowledge regarding the mechanisms of age‐related cardiac susceptibility and possible therapeutic interventions needs to be acquired to prevent advancing levels of heart disease. To understand more about the ageing heart, numerous aged animal models are being used to explore the underlying mechanisms. Due to time‐consuming for investigations involving naturally aged animals, mimetic ageing models are being utilized to assess the related effects of ageing on disease occurrence. d ‐galactose is one of the substances used to instigate ageing in various models, and techniques involving this have been widely used since 1991. However, the mechanism through which d ‐galactose induces ageing in the heart remains unclear. The aim of this review was to comprehensively summarize the current findings from in vitro and in vivo studies on the effects of d ‐galactose‐induced ageing on the heart, and possible therapeutic interventions against ageing heart models. From this review, we hope to provide invaluable information for future studies and based on the findings from experiments involving animals, we can inform possible therapeutic strategies for the prevention of age‐related heart diseases in clinical settings.     

A computational approach to studying ageing at the individual level

The ageing process is actively regulated throughout an organism''s life, but studying the rate of ageing in individuals is difficult with conventional methods. Consequently, ageing studies typically make biological inference based on population mortality rates, which often do not accurately reflect the probabilities of death at the individual level. To study the relationship between individual and population mortality rates, we integrated in vivo switch experiments with in silico stochastic simulations to elucidate how carefully designed experiments allow key aspects of individual ageing to be deduced from group mortality measurements. As our case study, we used the recent report demonstrating that pheromones of the opposite sex decrease lifespan in Drosophila melanogaster by reversibly increasing population mortality rates. We showed that the population mortality reversal following pheromone removal was almost surely occurring in individuals, albeit more slowly than suggested by population measures. Furthermore, heterogeneity among individuals due to the inherent stochasticity of behavioural interactions skewed population mortality rates in middle-age away from the individual-level trajectories of which they are comprised. This article exemplifies how computational models function as important predictive tools for designing wet-laboratory experiments to use population mortality rates to understand how genetic and environmental manipulations affect ageing in the individual.     

Adult Mortality Attributable to Preventable Risk Factors for Non-Communicable Diseases and Injuries in Japan: A Comparative Risk Assessment

Background

The population of Japan has achieved the longest life expectancy in the world. To further improve population health, consistent and comparative evidence on mortality attributable to preventable risk factors is necessary for setting priorities for health policies and programs. Although several past studies have quantified the impact of individual risk factors in Japan, to our knowledge no study has assessed and compared the effects of multiple modifiable risk factors for non-communicable diseases and injuries using a standard framework. We estimated the effects of 16 risk factors on cause-specific deaths and life expectancy in Japan.

Methods and Findings

We obtained data on risk factor exposures from the National Health and Nutrition Survey and epidemiological studies, data on the number of cause-specific deaths from vital records adjusted for ill-defined codes, and data on relative risks from epidemiological studies and meta-analyses. We applied a comparative risk assessment framework to estimate effects of excess risks on deaths and life expectancy at age 40 y. In 2007, tobacco smoking and high blood pressure accounted for 129,000 deaths (95% CI: 115,000–154,000) and 104,000 deaths (95% CI: 86,000–119,000), respectively, followed by physical inactivity (52,000 deaths, 95% CI: 47,000–58,000), high blood glucose (34,000 deaths, 95% CI: 26,000–43,000), high dietary salt intake (34,000 deaths, 95% CI: 27,000–39,000), and alcohol use (31,000 deaths, 95% CI: 28,000–35,000). In recent decades, cancer mortality attributable to tobacco smoking has increased in the elderly, while stroke mortality attributable to high blood pressure has declined. Life expectancy at age 40 y in 2007 would have been extended by 1.4 y for both sexes (men, 95% CI: 1.3–1.6; women, 95% CI: 1.2–1.7) if exposures to multiple cardiovascular risk factors had been reduced to their optimal levels as determined by a theoretical-minimum-risk exposure distribution.

Conclusions

Tobacco smoking and high blood pressure are the two major risk factors for adult mortality from non-communicable diseases and injuries in Japan. There is a large potential population health gain if multiple risk factors are jointly controlled. Please see later in the article for the Editors'' Summary     

Mental and Substance Use Disorders in Sub-Saharan Africa: Predictions of Epidemiological Changes and Mental Health Workforce Requirements for the Next 40 Years

The world is undergoing a rapid health transition, with an ageing population and disease burden increasingly defined by disability. In Sub-Saharan Africa the next 40 years are predicted to see reduced mortality, signalling a surge in the impact of chronic diseases. We modelled these epidemiological changes and associated mental health workforce requirements. Years lived with a disability (YLD) predictions for mental and substance use disorders for each decade from 2010 to 2050 for four Sub-Saharan African regions were calculated using Global Burden of Disease 2010 study (GBD 2010) data and UN population forecasts. Predicted mental health workforce requirements for 2010 and 2050, by region and for selected countries, were modelled using GBD 2010 prevalence estimates and recommended packages of care and staffing ratios for low- and middle-income countries, and compared to current staffing from the WHO Mental Health Atlas. Significant population growth and ageing will result in an estimated 130% increase in the burden of mental and substance use disorders in Sub-Saharan Africa by 2050, to 45 million YLDs. As a result, the required mental health workforce will increase by 216,600 full time equivalent staff from 2010 to 2050, and far more compared to the existing workforce. The growth in mental and substance use disorders by 2050 is likely to significantly affect health and productivity in Sub-Saharan Africa. To reduce this burden, packages of care for key mental disorders should be provided through increasing the mental health workforce towards targets outlined in this paper. This requires a shift from current practice in most African countries, involving substantial investment in the training of primary care practitioners, supported by district based mental health specialist teams using a task sharing model that mobilises local community resources, with the expansion of inpatient psychiatric units based in district and regional general hospitals.     

Early Mortality and Primary Causes of Death in Mothers of Children with Intellectual Disability or Autism Spectrum Disorder: A Retrospective Cohort Study

Introduction

Mothers of children with intellectual disability or autism spectrum disorder (ASD) have poorer health than other mothers. Yet no research has explored whether this poorer health is reflected in mortality rates or whether certain causes of death are more likely. We aimed to calculate the hazard ratios for death and for the primary causes of death in mothers of children with intellectual disability or ASD compared to other mothers.

Methods

The study population comprised all mothers of live-born children in Western Australia from 1983–2005. We accessed state-wide databases which enabled us to link socio-demographic details, birth dates, diagnoses of intellectual disability or ASD in the children and dates and causes of death for all mothers who had died prior to 2011. Using Cox Regression with death by any cause and death by each of the three primary causes as the event of interest, we calculated hazard ratios for death for mothers of children intellectual disability or ASD compared to other mothers.

Results and Discussion

During the study period, mothers of children with intellectual disability or ASD had more than twice the risk of death. Mothers of children with intellectual disability were 40% more likely to die of cancer; 150% more likely to die of cardiovascular disease and nearly 200% more likely to die from misadventure than other mothers. Due to small numbers, only hazard ratios for cancer were calculated for mothers of children with ASD. These mothers were about 50% more likely to die from cancer than other mothers. Possible causes and implications of our results are discussed.

Conclusion

Similar studies, pooling data from registries elsewhere, would improve our understanding of factors increasing the mortality of mothers of children with intellectual disability or ASD. This would allow the implementation of informed services and interventions to improve these mothers'' longevity.     

Progress in heart failure management in the Netherlands and beyond: long-term commitment to deliver high-quality research and patient care

Heart failure (HF) remains a major global problem. In the Netherlands, 1.5–2.0% of the total population is diagnosed with HF. Over 30,000 HF patients are admitted annually in the Netherlands, and this number is expected to further increase given the ageing population and the chronic nature of HF. Despite ongoing efforts to reduce the burden of HF, morbidity and mortality rates of this disease remain high. However, several new treatment modalities have become available or are expected to become available in the coming years. This review will provide an overview of HF research conducted in the Netherlands (often in an international setting) that may have clinical consequences for diagnosis, treatment and prevention of HF, and will also evaluate outcomes of larger clinical trials that have been conducted in the Netherlands.

     

The Age of Decline? Anxieties about Ageing in Japan

In the context of unprecedented life expectancy, the social position of the Japanese elderly is changing. Anxieties related to ageing are widely experienced by people of all ages and on a number of levels, including nationwide concerns over the ‘ageing population’ and its economic consequences; the ageing of local communities; on an interpersonal level, as older relatives may require care and support; and, finally, in relation to one's own ageing. These anxieties are examined based on ethnographic research in the city of Osaka. The concept of ikigai, often equated with purpose in life but closely associated with the elderly in public discourse, is used to illustrate how ageing implicates a number of apparently unconnected issues. It is argued that anxieties about ageing may ultimately achieve such prominence because they give focus to a range of fundamental human concerns with meaning, death, freedom, and isolation.     

Measuring the health of nations: analysis of mortality amenable to health care

Objective To assess whether and how the rankings of the world''s health systems based on disability adjusted life expectancy as done in the 2000 World Health Report change when using the narrower concept of mortality amenable to health care, an outcome more closely linked to health system performance.Design Analysis of mortality amenable to health care (including and excluding ischaemic heart disease).Main outcome measure Age standardised mortality from causes amenable to health careSetting 19 countries belonging to the Organisation for Economic Cooperation and Development.Results Rankings based on mortality amenable to health care (excluding ischaemic heart disease) differed substantially from rankings of health attainment given in the 2000 World Health Report. No country retained the same position. Rankings for southern European countries and Japan, which had performed well in the report, fell sharply, whereas those of the Nordic countries improved. Some middle ranking countries (United Kingdom, Netherlands) also fell considerably; New Zealand improved its position. Rankings changed when ischaemic heart disease was included as amenable to health care.Conclusion The 2000 World Health Report has been cited widely to support claims for the merits of otherwise different health systems. High levels of health attainment in well performing countries may be a consequence of good fortune in geography, and thus dietary habits, and success in the health effects of policies in other sectors. When assessed in terms of achievements that are more explicitly linked to health care, their performance may not be as good.     

'Positive biology' as a new paradigm for the medical sciences. Focusing on people who live long, happy, healthy lives might hold the key to improving human well-being

The nearly exclusive focus on understanding and treating chronic disease might not be the most efficient way to improve public health, especially as an effective alternative strategy exists.On 27 April 2009, during a speech at the National Academy of Sciences, US President Barack Obama pledged to invest more than 3% of US GDP in scientific research and development—the amount represented the largest ever investment in research and innovation. However, even a financial investment of such magnitude does not ensure that science is ''well-ordered'' [1], in the sense that the scientific research that is prioritized aspires to address the most significant challenges and problems for humanity.Among the many issues facing society that research must address, improving human health and tackling disease rank high, if not first, on the agenda. Accordingly, a huge fraction of research funding is spent on basic and applied research to further our understanding of the causes of disease and to find new cures and therapies. But is this focus on pathology the most efficient way to conduct research with the aim to improve human health and well-being?…a huge fraction of research funding is spent on basic and applied research to further our understanding of the causes of disease and to find new cures and therapiesMost of today''s medical research could be called ''negative biology''. It is conducted in an intellectual framework that presumes that the most important question to answer is: what causes pathology? Disease is its central focus and this explains why medical research and research funding is mainly concerned with trying to understand, prevent and treat specific diseases. The design of the US National Institutes of Health, which is largely composed of individual institutes dedicated to specific diseases such as cancer, mental illness or infectious diseases, reflects this prevalence of pathology-oriented negative biology.Positive biology, by contrast, focuses on a different set of questions and priorities. Rather than making pathology and disease the central focus of intellectual efforts and financial investments, positive biology seeks to understand positive phenotypes: why do some individuals live more than a century without ever suffering from the chronic diseases that afflict most humans much earlier in their lives? Why are some individuals more happy, optimistic, talented, or have a better memory than most people? The paradigm of positive biology is based on the insight that the process of evolution by natural selection does not create a perfect organism in terms of life expectancy, resistance to disease or other abilities. Observations of exceptional longevity or superior cognition therefore present fascinating puzzles for positive biology: which biological mechanisms would explain these exemplars of health and well-being? The goal of understanding positive phenotypes is that such knowledge might lead to new interventions that generally improve human well-being. This might be achieved by modulating the rate of ageing or by increasing opportunities for play and joy at all stages of the human lifespan, or by developing pharmaceuticals that safely enhance cognition or positive emotions, and so on.The goal of understanding positive phenotypes is that such knowledge might lead to new interventions that generally improve human well-beingThis is distinct from negative biology, which focuses on the proximate causes of specific diseases, rather than on the evolutionary causes of positive phenotypes. It presumes that health, survival and happiness are the default states and aims to explain the deviations: why do we develop cancer? Why do we suffer from depression? Why do we develop hypertension? Negative biology therefore faces the laudable but insurmountable task of trying to prevent or cure all disease. This is a costly and ultimately futile endeavour. Eliminating all types of cancer would increase life expectancy in the USA by approximately only three years [2]. Even eliminating cancer as a cause of death would not prevent any of the other chronic diseases of ageing—cardiovascular disease, Alzheimer and Parkinson disease, diabetes and so on—from afflicting the elderly. Moreover, the more than 40 years of ''war against cancer'' has not defeated a single type of cancer: we still have a long way to go before we can realistically expect to reap the three-year increase in life expectancy that eliminating all cancers could yield.In fact, negative biology has not yet developed a single cure for any one of the hundreds of chronic diseases that afflict millions of people living today. Of course, it has made significant advances to help prevent and treat chronic disease, but the fixation on pathology has meant that other potential avenues for research have been neglected.Indeed, a better understanding of exemplars of health and happiness—the goal of positive biology—could create more benefits for humans more quickly and more easily. A drug that would safely mimic the effects of caloric restriction, for instance, might delay, simultaneously, most diseases and afflictions of ageing. It would generate a much greater health dividend for ageing populations than defeating any one specific disease of ageing because slowing down the rate of ageing by seven years would reduce the age-specific risk of death, frailty and disability by about half at every age [3].Scientists are already making good progress on the project of positive biology, even if the intellectual framework is not yet clearly defined and their topics are rather piecemeal. Richard Miller, for example, a professor of pathology at Michigan University, USA, studies the genetics of ageing in mice and participates in the National Institute of Aging''s multi-institutional programme that evaluates the effects of drugs and nutriceuticals on the ageing process in mice. David Sinclair from Harvard University, USA, and others found that the plant compound resveratrol, which is found in the skin of grapes, can modulate the ageing process. Nir Barzilai and colleagues at the Albert Einstein School of Medicine in New York, USA, have conducted genetic research on more than 500 healthy elderly people between the ages of 95 and 112 years. Michael Rose from the University of California, Irvine, USA, has quadrupled the lifespan of fruit flies by delaying the age of reproduction. Finally, the biologist Cynthia Kenyon demonstrated that in Caenorhabditis elegans, a single gene can control the ageing process. Any of these research projects could eventually lead to the development of a new drug that retards the ageing process and diminishes the onslaught of chronic diseases that typically afflict humans after their sixth decade of life.Similarly, a lot of pioneering work is being undertaken in the burgeoning field of ''positive psychology''. Rather than studying why people suffer from mental illnesses such as depression, schizophrenia or ADHD (attention deficit hyperactivity disorder), positive psychology is primarily interested in how to improve the happiness of the ''average'' person. Martin Seligman, a psychologist at the University of Pennsylvania, USA, and a pioneer in the field of positive psychology, distinguishes different kinds and levels of happiness [4]. Hedonists who pursue immediate rewards such as the pleasure of buying something or receiving a compliment seek momentary happiness or what Seligman calls ''the pleasant life''. But these pleasures fade quickly and do not leave a lasting impact on subjective well-being. Enduring happiness, by contrast, is realized when we lead a meaningful life. After years spent studying what makes people happy, Seligman contends that it is rooted in attachment to something larger, and the larger the entity to which you attach yourself, the more meaning your life has [4].Eliminating all types of cancer would increase life expectancy in the USA by approximately only three yearsThis is clearly illustrated by the role of wealth. People often assume that being richer will mean being happier, yet surveys in many countries indicate that global levels of life satisfaction or happiness have not changed much during the past four decades despite large increases in real income per capita [5]. Most disposable income is spent on consumer goods that do little to actually enhance our well-being.In a recent study of the daily behaviour of happy people, researchers used an electronically activated recorder to record, and then later classify, participants'' daily conversations with others as either ''small talk'', that is banal conversations, and ''substantive talk'', where meaningful information was exchanged. They found that higher well-being was associated with less small talk and more substantive conversations [6]. While such a study does not establish the truth of Socrates'' famous claim that “the unexamined life is not worth living”, it does suggest that our need to feel attached to something larger is important to our happiness and well-being. This hypothesis is supported by recent studies on how people spend their money. Researchers from the University of British Columbia and Harvard Business School found that when individuals spend more money on prosocial goals, such as charity, they actually experience greater happiness than when they spend money on consumer products for themselves [7]. Similarly, the psychologist Barbara Fredrickson''s research on positive emotions—joy, serenity and gratitude—suggests that these expand cognition and behavioural tendencies [8].Finally, research on exemplars of resilience, that is, the ability of some people to cope and manage with tragic and traumatic events, could lead to the development of drugs that would increase people''s resilience. Avshalom Caspi and colleagues found that individuals with one or two copies of the short allele of the promoter of the 5-HTT serotonin receptor experience more depressive symptoms, diagnosable depression and suicidal thoughts in response to stressful events compared with individuals who are homozygous for the long allele [9].Cognitive functioning is another central topic of positive biology. What are the genetic and environmental determinants of high IQ, exceptional memory or social intelligence? Barbara Sahakian and colleagues found that the analeptic drug modafinil significantly enhanced performance tests of digit span, visual pattern recognition memory, spatial planning and stop-signal reaction time in healthy volunteers [10]. These findings of positive biology will eventually give us a better understanding of our human nature than the very limited focus on disease and pathology of negative biology and might then lead to new interventions, environments and attitudes that improve human well-being and happiness.Negative biology dominates medical research, from the questions research scientists tackle to the education of physicians and government regulation of health interventions. The dominance of this approach to the medical sciences presumes that the most important questions concern the causes of pathology rather than the causes of exemplar health and happiness. Positive biology takes a different approach: it does not limit the moral duty to apply knowledge and technology to improve human welfare to only treating specific diseases or impairments. Rather, it works under the assumption that if knowledge and research can improve people''s lives, there is a moral duty to advance that knowledge and promote well-being. Nor is positive biology predicated on a sharp distinction between therapy and enhancement. Instead, as the bioethicist John Harris has argued, “the overwhelming moral imperative for both therapy and enhancement is to prevent harm and confer benefit. Bathed in that moral light, it is unimportant whether the protection or benefit conferred is classified as enhancement or improvement, protection or therapy” [11].Generally, the medical system as a whole could be much more efficient if it concentrated its efforts on making people healthier and happier in the first place instead of its current focus on understanding and treating disease. Advancing the paradigm of positive biology should therefore help the medical sciences transcend the limited perspectives and aspirations of negative biology. Such a paradigm could help the world''s population to reap the benefits that new knowledge and technologies can offer in terms of making people healthier and happier. Societies and individuals already seek to achieve these goals: we educate our children to eat healthily and exercise and to develop their social goals to find fulfilment in life. The paradigm of positive biology simply encourages us to make use of the full range of options to realize these goals.…the medical system as a whole could be much more efficient if it concentrated its efforts on making people healthier and happier in the first place…In conclusion, positive biology is not contrary to the goals and aspirations of negative biology. Indeed the two paradigms are often complementary. For example, understanding why some high-risk individuals, such as sex workers, seem to have an intrinsic resistance to HIV-1 might spur the development of an HIV vaccine [12]. Similarly, understanding human brains with exceptional cognitive functioning might lead to new avenues for developing drugs and therapies against severe cognitive impairment. Understanding exemplars of health could create real benefits for those who are more vulnerable to disease and disability.     

Nutrition chez les séniors

The population of industrialized countries is aging with an already significant proportion of individuals over 65 years old. Statistics show a difference of around 20 years between overall longevity and that without disability, this latter being a public health problem. Thus, the prevention measures are major in order to ensure the population a healthy aging, offering the best possible autonomy. Nutrition occupies a prominent place for improving the health of the elderly, together with maintaining physical exercise adapted to the possibilities of each person. In a physiological context of sarcopenia, which can participate to the establishment of undernutrition whose consequences are well-known for the aggravation of morbidity and mortality, the key word will remain diversification and nutritional balance, tending to maintain the appetite and to avoid monotony.     

Doctors and patients don't agree: cross sectional study of patients' and doctors' perceptions and assessments of disability in multiple sclerosis.

OBJECTIVES: To compare the judgments of clinicians on which domains of health in the short form questionnaire (SF-36) would be most important to patients with multiple sclerosis with the opinions of patients themselves; to compare assessment of physical disability in multiple sclerosis by a clinician using Kurtzke''s expanded disability status scale and a non-clinically qualified assistant using the Office of Population Census and Surveys'' (OPCS) disability scale with self assessment of disability and other domains of health related quality of life by patients using the SF-36 and the EuroQol questionnaire; and to compare the scores of patients for each domain of the SF-36 with control data matched for age and sex. DESIGN: Cross sectional study. SETTING: Clinical department of neurology, Edinburgh. SUBJECTS: 42 consecutive patients with multiple sclerosis attending a neurology outpatient clinic for review or a neurology ward for rehabilitation. MAIN OUTCOME MEASURES: Scores on the SF-36; EuroQol; Kurtzke''s expanded disability status scale; the OPCS disability scale. RESULTS: Patients and clinicians disagreed on which domains of health status were most important (chi 2 = 21, df = 7, P = 0.003). Patients'' assessment of their physical disability using the physical functioning domain of the SF-36 was highly correlated with the clinicians'' assessment (r = -0.87, P < 0.001) and the non-clinical assessment (r = -0.90, P < 0.001). However, none of the measures of physical disability correlated with overall health related quality of life measured with EuroQol, Quality of life correlated with vitality, general health, and mental health in the SF-36, each of which patients rated as more important than clinicians and for each of which patients scored lower than the controls. CONCLUSIONS: Patients with multiple sclerosis and possibly those with other chronic diseases are less concerned than their clinicians about physical disability in their illness. Clinical trials in multiple sclerosis should assess the effect of treatment on the other elements of health status that patients consider important, which are also affected by the disease process, are more closely related to overall health related quality of life, and may well be adversely affected by side effects of treatment.     

Burden of Depressive Disorders by Country,Sex, Age,and Year: Findings from the Global Burden of Disease Study 2010

Background

Depressive disorders were a leading cause of burden in the Global Burden of Disease (GBD) 1990 and 2000 studies. Here, we analyze the burden of depressive disorders in GBD 2010 and present severity proportions, burden by country, region, age, sex, and year, as well as burden of depressive disorders as a risk factor for suicide and ischemic heart disease.

Methods and Findings

Burden was calculated for major depressive disorder (MDD) and dysthymia. A systematic review of epidemiological data was conducted. The data were pooled using a Bayesian meta-regression. Disability weights from population survey data quantified the severity of health loss from depressive disorders. These weights were used to calculate years lived with disability (YLDs) and disability adjusted life years (DALYs). Separate DALYs were estimated for suicide and ischemic heart disease attributable to depressive disorders.Depressive disorders were the second leading cause of YLDs in 2010. MDD accounted for 8.2% (5.9%–10.8%) of global YLDs and dysthymia for 1.4% (0.9%–2.0%). Depressive disorders were a leading cause of DALYs even though no mortality was attributed to them as the underlying cause. MDD accounted for 2.5% (1.9%–3.2%) of global DALYs and dysthymia for 0.5% (0.3%–0.6%). There was more regional variation in burden for MDD than for dysthymia; with higher estimates in females, and adults of working age. Whilst burden increased by 37.5% between 1990 and 2010, this was due to population growth and ageing. MDD explained 16 million suicide DALYs and almost 4 million ischemic heart disease DALYs. This attributable burden would increase the overall burden of depressive disorders from 3.0% (2.2%–3.8%) to 3.8% (3.0%–4.7%) of global DALYs.

Conclusions

GBD 2010 identified depressive disorders as a leading cause of burden. MDD was also a contributor of burden allocated to suicide and ischemic heart disease. These findings emphasize the importance of including depressive disorders as a public-health priority and implementing cost-effective interventions to reduce its burden. Please see later in the article for the Editors'' Summary     

Health effects of obstructive sleep apnoea and the effectiveness of continuous positive airways pressure: a systematic review of the research evidence.

OBJECTIVE: To examine the research evidence for the health consequences of obstructive sleep apnoea and the effectiveness of continuous positive airways pressure. DESIGN: A systematic review of published research, studies being identified by searching Medline (1966-96), Embase (1974-96), and CINAHL (Cumulative Index to Nursing and Allied Health Literature) (1982-95); scanning citations; and consulting experts. Studies in all languages were considered which either investigated the association between obstructive sleep apnoea in adults and key health outcomes or evaluated the effectiveness of treatment of obstructive sleep apnoea with continuous positive airways pressure in adults. MAIN OUTCOME MEASURES: Mortality, systematic hypertension, cardiac arrhythmias, ischaemic heart disease, left ventricular hypertrophy, pulmonary hypertension, stroke, vehicle accidents, measures of daytime sleepiness, and quality of life. RESULTS: 54 epidemiological studies examined the association between sleep apnoea and health related outcomes. Most were poorly designed and only weak or contradictory evidence was found of an association with cardiac arrhythmias, ischaemic heart disease, cardiac failure, systemic or pulmonary hypertension, and stroke. Evidence of a link with sleepiness and road traffic accidents was stronger but inconclusive. Only one small randomised controlled trial evaluated continuous positive airways pressure. Five non-randomised controlled trials and 38 uncontrolled trials were identified. Small changes in objectively measured daytime sleepiness were consistently found, but improvements in morbidity, mortality, and quality of life indicators were not adequately assessed. CONCLUSIONS: The relevance of sleep apnoea to public health has been exaggerated. The effectiveness of continuous positive airways pressure in improving health outcomes has been poorly evaluated. There is enough evidence suggesting benefit in reducing daytime sleepiness in some patients to warrant large randomised placebo controlled trials of continuous positive airways pressure versus an effective weight reduction programme and other interventions.     

Raynaud's phenomenon in forestry workers in Quebec.

A survey of 1540 forestry workers in Quebec found a prevalence of Raynaud''s phenomenon of 30.5% among chain-saw users and 8.7% among nonusers. Prevalence was related directly to duration of use of the chain-saw. The mean interval (+/- the standard deviation) between the time the chain-saw was first used and the onset of Raynaud''s phenomenon was 7.8 +/- 5.6 years. After 20 years of chain-saw use over 50% of the population had Raynaud''s phenomenon. Relative risks among those using a chain-saw for more than 10 years were 3.60 for nonsmokers and 6.55 for smokers. Other factors associated with the phenomenon included a family history of nonoccupational Raynaud''s phenomenon, previous injuries to the arms, climate and type of residence during the wood-cutting season. Decreased work capacity, interference with leisure activities and changes in professional orientation often resulted from this disease. These problems should be taken into account when disability compensation is being considered.     

Gender Differences in Health Expectancies across the Disablement Process among Older Thais

Objectives

To estimate health expectancies based on measures that more fully cover the stages in the disablement process for the older Thais and examine gender differences in these health expectancies.

Methods

Health expectancies by genders using Sullivan’s method were computed from the fourth Thai National Health Examination Survey conducted in 2009. A total of 9,210 participants aged 60 years and older were included in the analysis. Health measures included chronic diseases; cognitive impairment; depression; disability in instrumental activities of daily living (IADL); and disability in activities of daily living (ADL).

Results

The average number of years lived with and without morbidity and disability as measured by multiple dimensions of health varied and gender differences were not consistent across measures. At age 60, males could expect to live the most years on average free of depression (18.6 years) and ADL disability (18.6 years) and the least years free of chronic diseases (9.1 years). Females, on the contrary, could expect to live the most years free of ADL disability (21.7 years) and the least years free of IADL disability (8.1 years), and they consistently spent more years with all forms of morbidity and disability. Finally, and for both genders, years lived with cognitive impairment, depression and ADL disability were almost constant with increasing age.

Conclusion

This study adds knowledge of gender differences in healthy life expectancy in the older Thai population using a wider spectrum of health which provides useful information to diverse policy audiences.     

Impact of diurnal temperature range on human health: a systematic review

Increasing epidemiological studies have shown that a rapid temperature change within 1 day is an independent risk factor for human health. This paper aimed to systematically review the epidemiological evidence on the relationship between diurnal temperature range (DTR) and human health and to propose future research directions. A literature search was conducted in October 2013 using the databases including PubMed, ScienceDirect, and EBSCO. Empirical studies regarding the relationship between DTR and mortality and morbidity were included. Twenty-five relevant studies were identified, among which, 11 investigated the relationship between DTR and mortality and 14 examined the impact of DTR on morbidity. The majority of existing studies reported that DTR was significantly associated with mortality and morbidity, particularly for cardiovascular and respiratory diseases. Notably, compared with adults, the elderly and children were more vulnerable to DTR effects. However, there were some inconsistencies regarding the susceptible groups, lag time, and threshold of DTR. The impact of DTR on human health may be confounded or modified by season, socioeconomic, and educational status. Further research is needed to further confirm the adverse effects of DTR in different geographical locations; examine the effects of DTR on the health of children aged one or under; explore extreme DTR effects on human health; analyze the difference of DTR effects on human health in different locations and the modified effects of potential confounding factors; and develop detailed preventive measures against large DTR, particularly for susceptible groups.     

Heritable strategies for controlling insect vectors of disease

Mosquito-borne diseases are causing a substantial burden of mortality, morbidity and economic loss in many parts of the world, despite current control efforts, and new complementary approaches to controlling these diseases are needed. One promising class of new interventions under development involves the heritable modification of the mosquito by insertion of novel genes into the nucleus or of Wolbachia endosymbionts into the cytoplasm. Once released into a target population, these modifications can act to reduce one or more components of the mosquito population''s vectorial capacity (e.g. the number of female mosquitoes, their longevity or their ability to support development and transmission of the pathogen). Some of the modifications under development are designed to be self-limiting, in that they will tend to disappear over time in the absence of recurrent releases (and hence are similar to the sterile insect technique, SIT), whereas other modifications are designed to be self-sustaining, spreading through populations even after releases stop (and hence are similar to traditional biological control). Several successful field trials have now been performed with Aedes mosquitoes, and such trials are helping to define the appropriate developmental pathway for this new class of intervention.