The interaction between the equity premium and the risk-free rate

The equity premium arises from the interaction between the atemporal risk premium for equity, the risk-free rate of intertemporal substitution and the impact of risk on the precautionary motive for saving. Depending on parameter values, the equity premium may either be increased or reduced by the presence of undiversifiable background risk. (C) 2000 Elsevier Science S.A. All rights reserved.

Background risk in generalized expected utility theory

In this paper, it is shown that, for a wide range of risk-averse generalized expected utility preferences, independent risks are complementary, contrary to the results for expected utility preferences satisfying conditions such as proper and standard risk aversion.

A practical approach to assess depression risk and to guide risk reduction strategies in later life

Background: Many factors have been associated with the onset and maintenance of depressive symptoms in later life, although this knowledge is yet to be translated into significant health gains for the population. This study gathered information about common modifiable and non-modifiable risk factors for depression with the aim of developing a practical probabilistic model of depression that can be used to guide risk reduction strategies. \Methods: A cross-sectional study was undertaken of 20,677 community-dwelling Australians aged 60 years or over in contact with their general practitioner during the preceding 12 months. Prevalent depression (minor or major) according to the Patient Health Questionnaire (PHQ-9) assessment was the main outcome of interest. Other measured exposures included self-reported age, gender, education, loss of mother or father before age 15 years, physical or sexual abuse before age 15 years, marital status, financial stress, social support, smoking and alcohol use, physical activity, obesity, diabetes, hypertension, and prevalent cardiovascular diseases, chronic respiratory diseases and cancer. Results: The mean age of participants was 71.7 +/- 7.6 years and 57.9% were women. Depression was present in 1665 (8.0%) of our subjects. Multivariate logistic regression showed depression was independently associated with age older than 75 years, childhood adverse experiences, adverse lifestyle practices (smoking, risk alcohol use, physical inactivity), intermediate health hazards (obesity, diabetes and hypertension), comorbid medical conditions (clinical history of coronary heart disease, stroke, asthma, chronic obstructive pulmonary disease, emphysema or cancers), and social or financial strain. We stratified the exposures to build a matrix that showed that the probability of depression increased progressively with the accumulation of risk factors, from less than 3% for those with no adverse factors to more than 80% for people reporting the maximum number of risk factors. Conclusions: Our probabilistic matrix can be used to estimate depression risk and to guide the introduction of risk reduction strategies. Future studies should now aim to clarify whether interventions designed to mitigate the impact of risk factors can change the prevalence and incidence of depression in later life.

Myocardial Perfusion Imaging Is a Strong Predictor of Death in Women

OBJECTIVES We sought to assess the prognostic value and risk classification improvement using contemporary single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) to predict all-cause mortality. BACKGROUND Myocardial perfusion is a strong estimator of prognosis. Evidence published to date has not established the added prognostic value of SPECT-MPI nor defined an approach to detect improve classification of risk in women from a developing nation. METHODS A total of 2,225 women referred for SPECT-MPI were followed by a mean period of 3.7 +/- 1.4 years. SPECT-MPI results were classified as abnormal on the presence of any perfusion defect. Abnormal scans were further classified as with mild/moderate reversible, severe reversible, partial reversible, or fixed perfusion defects. Risk estimates for incident mortality were categorized as <1%/year, 1% to 2%/year, and >2%/year using Cox proportional hazard models. Risk-adjusted models incorporated clinical risk factors, left ventricular ejection fraction (LVEF), and perfusion variables. RESULTS All-cause death occurred in 139 patients. SPECT-MPI significantly risk stratified the population; patients with abnormal scans had significantly higher death rates compared with patients with normal scans, 13.1% versus 4.0%, respectively (p < 0.001). Cox analysis demonstrated that after adjusting for clinical risk factors and LVEF, SPECT-MPI improved the model discrimination (integrated discrimination index = 0.009; p = 0.02), added significant incremental prognostic information (global chi-square increased from 87.7 to 127.1; p < 0.0001), and improved risk prediction (net reclassification improvement = 0.12; p = 0.005). CONCLUSIONS SPECT-MPI added significant incremental prognostic information to clinical and left ventricular functional variables while enhancing the ability to classify this Brazilian female population into low-and high-risk categories of all-cause mortality. (J Am Coll Cardiol Img 2011;4:880-8) (C) 2011 by the American College of Cardiology Foundation

Prognostic heterogeneity among patients with chronic stable coronary disease: determinants of long-term mortality after treatment with percutaneous intervention

Aims: To evaluate the risk and predictors of death in a large population of patients with stable coronary disease treated with percutaneous intervention. Methods and results: The study population comprised 1,276 patients with chronic angina or silent ischaemia who underwent elective coronary angioplasty. Baseline and in-hospital mortality data were prospectively collected for all patients during the index hospitalisation. Post-discharge outcome was assessed at out-patient clinic, by review of the patients` records, or direct phone contact. Deaths were classified as cardiac and non-cardiac. Age, peripheral arterial disease, congestive heart failure with NYHA class Ill, triple-vessel disease, and procedural success (i.e. angiographic success for all lesions in the absence of pen-procedural infarction) remained as multivariate independent predictors of death. For the entire population 4-year cumulative all-cause and cardiac mortality were respectively 5.4% and 4.1%. Four-year mortality for patients without any multivariate predictor was 2.4%, while for patients with two or more predictors the death rate was 16.3% after four years. Conclusions: Patients with stable coronary disease undergoing percutaneous treatment have an overall low mortality rate after four years. Nevertheless, stable patients comprise a heterogeneous population in terms of risk profile, ranging from patients at very low risk of late death to individuals with a poor long-term prognosis.

Improved Endothelial Function and Reversal of Myocardial Perfusion Defects after Aerobic Physical Training in a Patient with Microvascular Myocardial Ischemia

The objective of this report is to document the effects of an aerobic training program on myocardial perfusion, and endothelial function abnormalities, and on the relief of angina in a patient with microvascular myocardial ischemia. A 53-year-old female patient exhibited precordial pain on effort and angiographically normal coronaries. Her symptoms had been present for 4 yrs despite pharmacologic treatment for the control of risk factors, with myocardial perfusion scintigraphy revealing an extensive reversible perfusion defect. She was submitted to aerobic training for 4 mos, obtaining significant improvement of the anginal symptoms. Additionally, after the aerobic training program, scintigraphy revealed the disappearance of the myocardial perfusion defect, with a marked improvement of endothelium-dependent vasodilatory response and an improved quality-of-life score. These results suggest that aerobic training can improve endothelial function, leading to a reduction of ischemia and an improved quality-of-life in patients with microvascular myocardial ischemia.

Enhanced concentrations of relevant markers of nitric oxide formation after exercise training in patients with metabolic syndrome

Metabolic syndrome (MetS) denotes a clustering of risk factors that may affect nitric oxide (NO) bioavailability and predispose to cardiovascular diseases, which are delayed by exercise training. However, no previous study has examined how MetS affects markers of NO formation, and whether exercise training increases NO formation in MetS patients. Here, we tested these two hypotheses. We studied 48 sedentary individuals: 20 healthy controls and 28 MetS patients. Eighteen MetS patients were subjected to a 3-month exercise training (E+group), while the remaining 10 MetS patients remained sedentary (E-group). The plasma concentrations of nitrite, cGMP, and ADMA (asymmetrical dimethylarginine: an endogenous nitric oxide synthase inhibitor), and the whole blood nitrite concentrations were determined at baseline and after exercise training using an ozone-based chemiluminescence assay, and commercial enzyme immunoassays. Thiobarbituric acid reactive species (TBA-RS) were measured in the plasma to assess oxidative stress using a fluorometric method. We found that, compared with healthy subjects, patients with MetS have lower concentrations of markers of NO formation, including whole blood nitrite, plasma nitrite, and plasma cGMP, and increased oxidative stress (all P < 0.05). Exercise training increased the concentrations of whole blood nitrite and cGMP, and decreased both oxidative stress and the circulating concentrations of ADMA (both P < 0.05). These findings show clinical evidence for lower endogenous NO formation in patients with MetS, and for improvements in NO formation associated with exercise training in MetS patients. (C) 2008 Elsevier Inc. All rights reserved.

Accuracy of intraoperative cultures in primary total hip arthroplasty

The aim of this investigation was to assess the diagnostic accuracy of intraoperative cultures for the early identification of patients who are at risk of infection after primary total hip arthroplasty. Four or six swabs were obtained immediately before the wound closure in 263 primary total hip replacements. Patients with a maximum of one positive culture were denoted as patients with a normal profile and did not receive any treatment. Patients with two or more positive cultures, with the same organism identified, were denoted as patients with a risk profile and received treatment with a specific antibiotic as determined by the antibiogram for six weeks. The follow-up ranged from a minimum of one year to five years and eleven months, concentrating on the presence or absence of infection, which was defined as discharge of pus through the surgical wound or as a fistula at any time after surgery. The accuracy of this procedure ( number of cases correctly identified in relation to the total number of cases) in the group of 152 arthroplasties in which 4 swabs per patient were collected was 96%. In the group of 111 arthroplasties in which 6 swabs per patient were collected the accuracy was 95.5%. We conclude that the collection of swabs under the conditions described is a method of high accuracy ( above 95%) for the evaluation of risk of infection after primary total hip arthroplasty.

Opportunities for the control of coronary heart disease in Australia

Objective: To estimate the number of coronary events that could be prevented in Australia each year by the use of preventive and therapeutic strategies targeted to subgroups of the population based on their levels of risk and need. Methods: Estimates of risk reduction from the published literature, prevalence estimates of elevated risk factor levels from the 1995 National Health Survey and treatment levels from the Australian collaborating centres in the World Health Organization's MONICA Project were used to calculate numbers of coronary events preventable among men and women aged 35-79 years in Australia. Results: Approximately 14,000 coronary events could be avoided each year if the mean level of cholesterol in the population was reduced by 0.5 mmol/L, smoking prevalence was halved and prevalence of physical inactivity was reduced to 25%. This represents a reduction in coronary events of about 40%. Even with less optimistic targets, a reduction of 20% could be attained, while the achievement of some internationally recommended targets could lead to almost 50% reduction. In the short term, aggressive medical treatment of people with elevated levels of risk factors and established coronary disease offers the greatest opportunity for reducing coronary events. Conclusion: A comprehensive approach to reduce levels of behavioural and biological risk factors and improve the use of effective treatment could lead to a large reduction in coronary event rates. In the long term, primary prevention - especially to reduce smoking, lower cholesterol levels and increase exercise - has the potential to reduce the population levels of risk and hence contain the national cost of coronary disease.

An evaluation of a suburban railway pedestrian crossing safety programme

This study evaluated a programme of educational and environmental (access prevention) interventions designed to reduce the incidence of illegal and unsafe crossing of the rail corridor at a suburban station in Auckland, New Zealand. Immediately after the programme of interventions, the proportion of those crossing the rail corridor by walking across the tracks directly rather than using the nearby overbridge had decreased substantially. Three months later, the decrease was even greater. However, the educational and environmental interventions were introduced simultaneously so that the effects of each could not be separated, nor could other unmeasured factors be ruled out. Anonymous surveys administered immediately before and 3 months after the interventions indicated that while awareness of the illegality of walking across the tracks had increased slightly, perception of risk had not changed. This suggests that the educational interventions may have had less effect than the access prevention measures. (C) 2001 Elsevier Science Ltd. All rights reserved.

Public policy and the prevention of substance-use disorders

Drug prevention has traditionally focused on influencing individual attitudes and behaviours. In particular, efforts have been directed towards adolescents in the school setting. However, evaluations of school-based drug education have identified limited success. There is increasing recognition that drug abuse is one of a number of risk behaviours, including truancy, delinquency and mental health problems, which share common antecedents that begin in the early years of childhood. Furthermore, these behaviours are shaped by macroenvironmental influences including the economic, social, cultural, and physical environment. Drug prevention needs to adopt a broader perspective: with greater collaboration in related programmes such as crime prevention and suicide prevention; with greater attention to the macroenvironmental influences on problem behaviours; and with greater attention to healthy development in the first years of childhood. (C) 2002 Lippincott Williams Wilkins.

Consumers' perceived risk: Sources versus consequences

In this study, we examine an important factor that affects consumers' acceptance of business-to-commerce (B2C) electronic commerce - perceived risk. The objective of this paper is to examine the definition of perceived risk in the context of B2C electronic commerce. The paper highlights the importance of perceived risk and the interwoven relation between perceived risk and trust. It discusses the problem of defining perceived risk in prior B2C research. This study proposes a new classification of consumers' perceived risk based on sources. It highlights the importance of identifying the sources of consumer's risk perceptions in addition to the consequences dimensions. Two focus group discussion sessions were conducted to verify the proposed classification. Results indicate that Internet consumers perceive three sources of risk in B2C electronic commerce: technology, vendor, and product. © 2003 Elsevier B.V. All rights reserved.

The genetics of coronary heart disease: the contribution of twin studies

Despite the decline in coronary heart disease in many European countries, the disease remains an enormous public health problem. Although we know a great deal about environmental risk factors for coronary heart disease, a heritable component was recognized a long time ago. The earliest and best known examples of how our genetic constitution may determine cardiovascular risk relate to lipoprotein(a), familial hypercholesterolaemia and apolipoprotein E. In the past 20 years a fair number of polymorphisms assessed singly have shown strong associations with the disease but most are subject to poor repeatability. Twins constitute a compelling natural experiment to establish the genetic contribution to coronary heart disease and its risk factors. GenomEUtwin, a recently funded Framework 5 Programme of the European Community, affords the opportunity of comparing the heritability of risk factors in different European Twin Registries. As an illustration we present the heritabilities of systolic and diastolic blood pressure, based on data from over 4000 twin pairs from six different European countries and Australia. Heritabilities for systolic blood pressure are between 52 and 66% and for diastolic blood pressure between 44 and 66%. There is no evidence of sex differences in heritability estimates and very little to no evidence for a significant contribution of shared family environment. A non-twin based prospective case/cohort study of coronary heart disease and stroke (MORGAM) will allow hypotheses relating to cardiovascular disease, generated in the twin cohorts, to be tested prospectively in adult populations. Twin studies have also contributed to our understanding of the life course hypothesis, and GenomEUtwin has the potential to add to this.

Clinical aspects of gestational trophoblastic disease: A review based partly on 25-year experience of a statewide registry

Background: Gestational trophoblastic disease is a fascinating group of pregnancy disorders characterised by abnormal proliferation of trophoblast, ranging from benign to malignant. Because the disease is uncommon, there is a need to formulate management with the assistance of collective information. Methodology: A review of available information from English written literature was undertaken especially data reported by registries around the world (Charing Cross Hospital in England, the North-western University and the New England area in the USA as well as our own experience in Queensland, Australia). Where possible, collated data from relevant studies were analysed to answer some of the questions posed in clinical practice, with reference to metastatic disease to liver and brain, twinning of molar gestation and coexisting fetus, and placental-site tumour. Results: We found that molar gestation can be classified according to its clinical presentation which influences the time taken to reach human chorionic gonadotropin (HCG) 'negativity' and the risk of persisting disease. Categorisation of risk is the basis for choice of chemotherapy to achieve good outcomes. Metastases to liver and brain remain problems in management; the development of 'new' metastases during chemotherapy is a very poor prognostic factor. In the variant of twinning with molar gestation and coexisting fetus, it is important to elucidate the fetal karyotype in planning management: a 69XXX fetus is not salvageable but a normal 46XX or 46XY fetus faces the prospect of early preterm delivery. The placental-site tumour is very rare; localised disease is curable by surgery; chemotherapy is less effective in disseminated disease. From collated worldwide data, the recurrence rate after one mole is 1.3% and after two or more is 20%. Reproductive outcome in subsequent pregnancies, even after multidrug chemotherapy, is not different from the general population. Because of the increased risk long-term of second tumours after multidrug chemotherapy a closer surveillance of these patients is necessary Conclusion: In general, the disease in its persisting or malignant form is 'a cancer model par excellence' because of an identifiable precursor condition, a reliable HCG marker, and sensitivity of the disease to cytotoxic drugs. With current management, retention of fertility is possible and normal reproductive outcome assured.

Efeitos do acompanhamento de analistas e da dupla listagem sobre o disclosure voluntário durante o processo de convergência ao padrão IFRS no Brasil

Objetivou-se com o presente trabalho, estudar os efeitos da convergência às normas internacionais de contabilidade (IFRS), da cobertura de analistas financeiros e da emissão de American Depositary Receipts - ADR, sobre o disclosure voluntário das empresas listadas na BM&FBOVESPA. Partindo-se da análise de 14 trabalhos acadêmicos, desenvolveu-se um índice de disclosure voluntário contendo um total de 38 itens, sendo 25 itens de natureza financeira, econômica e organizacional e 13 itens de natureza social e ambiental. O check list do índice desenvolvido foi aplicado sobre 1.406 documentos (notas explicativas e relatórios da administração, contendo 58,2 mil páginas), de uma amostra com 703 observações - ano, obtidas durante os anos de 2006 a 2013. Utilizando-se do teste de Wilcoxon, os resultados apontam incrementos estatisticamente significantes nos níveis de disclosure voluntário durante o período de convergência ao padrão IFRS no Brasil, sendo mais significativos elementos de natureza econômica, financeira e organizacional do que os de natureza social e ambiental. Utilizando-se de modelos OLS robustos, aplicados sobre dados em painel desbalanceado, os resultados dos testes econométricos confirmaram parcialmente a hipótese de que o padrão IFRS contribuiu no desenvolvimento do disclosure voluntário das empresas com maior acompanhamento de analistas financeiros, porém, significativamente para as empresas que emitiram American Depositary Receipts (ADR) durante o período de convergência às normas internacionais de contabilidade. Os resultados são robustos e significativos quando controlados por variáveis representativas do tamanho (TAM), da rentabilidade (RENT), do endividamento (ALAV) e de auditoria de uma big – four (AUDI) como determinantes do disclosure voluntário durante o período de convergência ao padrão IFRS no Brasil.