Parametric conditional frailty models for recurrent cardiovascular events in the lipid study

Background Analysis of recurrent event data is frequently needed in clinical and epidemiological studies. An important issue in such analysis is how to account for the dependence of the events in an individual and any unobserved heterogeneity of the event propensity across individuals.Methods We applied a number of conditional frailty and nonfrailty models in an analysis involving recurrent myocardial infarction events in the Long-Term Intervention with Pravastatin in Ischaemic Disease study. A multiple variable risk prediction model was developed for both males and females. Results A Weibull model with a gamma frailty term fitted the data better than other frailty models for each gender. Among nonfrailty models the stratified survival model fitted the data best for each gender. The relative risk estimated by the elapsed time model was close to that estimated by the gap time model. We found that a cholesterol-lowering drug, pravastatin (the intervention being tested in the trial) had significant protective effect against the occurrence of myocardial infarction in men (HR¼0.71, 95% CI0.60–0.83). However, the treatment effect was not significant in women due to smaller sample size (HR¼0.75, 95% CI 0.51–1.10). There were no significant interactions between the treatment effect and each recurrent MI event (p¼0.24 for men and p¼0.55 for women). The risk of developing an MI event for a male who had an MI event during follow-up was about 3.4 (95% CI 2.6–4.4) times the risk compared with those who did not have an MI event. The corresponding relative risk for a female was about 7.8 (95% CI 4.4–13.6). Limitations The number of female patients was relatively small compared with their male counterparts, which may result in low statistical power to find real differences in the effect of treatment and other potential risk factors.Conclusions The conditional frailty model suggested that after accounting for all the risk factors in the model, there was still unmeasured heterogeneity of the risk for myocardial infarction, indicating the effect of subject-specific risk factors. These risk prediction models can be used to classify cardiovascular disease patients into different risk categories and may be useful for the most effective targeting of preventive therapies for cardiovascular disease.

Cardiovascular risk prediction model development and assessment

The aim of this article is to review the development and assessment of cardiovascular risk prediction models and to discuss the predictive value of a risk factor as well as to introduce new assessment methods to evaluate a risk prediction model. Many cardiovascular risk prediction models have been developed during the past three decades. However, there has not been consistent agreement regarding how to appropriately assess a risk prediction model, especially when new markers are added to an existing model. The area under the receiver operating characteristic (ROC) curve has traditionally been used to assess the discriminatory ability of a risk prediction model. However, recent studies suggest that this method has its limitations and cannot be the sole approach to evaluate the usefulness of a new marker. New assessment methods are being developed to appropriately assess a risk prediction model and they will be gradually used in clinical and epidemiological studies.

Corporate governance, firm characteristics and risk management committee formation in Australian companies

Purpose – The purpose of this paper is to examine how a risk management committee (RMC), as a newly evolving sub-committee of the board of directors, functions as a key governance support mechanism in the oversight an organisation's risk management strategies, policies and processes. However, empirical evidence on the factors associated with the existence and the type of RMCs remains scant.

Design/methodology/approach – Using an agency theory perspective, this study investigates the association between board factors such as proportion of non-executive directors, Chief Executive Officer duality, and board size; as well as, other firm-related factors (e.g. auditor type, industry, leverage, and complexity), and the existence of a RMC, and the type of RMC (namely, a separate RMC versus one that is combined with the audit committee). Data was collected from the annual reports of the top 300 Australian Stock Exchange (ASX)-listed companies.

Findings – The results, based on logistic regression analyses, indicate that RMCs tend to exist in companies with an independent board chairman and larger boards. Further, the results also indicate that in comparison to companies with a combined RMC and audit committee, those with a separate RMC are more likely to have larger boards, higher financial reporting risk and lower organisational complexity.

Research limitations/implications – Data limited to top 200 top ASX-listed companies, thus restricting generalisability of the results.

Originality/value – The findings of this study provide additional information on the use and design of RMCs in a voluntary setting.

Are youth mentoring programs good value-for-money? An evaluation of the Big Brothers Big Sisters Melbourne program

Background : The Big Brothers Big Sisters (BBBS) program matches vulnerable young people with a trained, supervised adult volunteer as mentor. The young people are typically seriously disadvantaged, with multiple psychosocial problems.

Methods : Threshold analysis was undertaken to determine whether investment in the program was a worthwhile use of limited public funds. The potential cost savings were based on US estimates of life-time costs associated with high-risk youth who drop out-of-school and become adult criminals. The intervention was modelled for children aged 10–14 years residing in Melbourne in 2004.

Results : If the program serviced 2,208 of the most vulnerable young people, it would cost AUD 39.5 M. Assuming 50% were high-risk, the associated costs of their adult criminality would be AUD 3.3 billion. To break even, the program would need to avert high-risk behaviours in only 1.3% (14/1,104) of participants.

Conclusion : This indicative evaluation suggests that the BBBS program represents excellent 'value for money'.

The money laundering risk posed by low-risk financial products in South Africa : findings and guidelines

Purpose – The purpose of this paper is to investigate the level and nature of criminal abuse of financial products that are classified as posing a low anti-money laundering/combating of financing of terrorists (AML/CFT) risk in South Africa to determine the effectiveness of the simplified due diligence measures that apply to these products.

Design/methodology/approach – The paper presents empirical research on the views of bank officials and law enforcement officials regarding the criminal abuse of South African financial products that are subject to simplified customer due diligence controls.

Findings – South Africa's AML/CFT laws allow certain deposit-taking institutions and money remitters to implement simplified customer due diligence measures in relation to specific low-risk products that are mainly designed to allow previously unbanked persons to access financial services. The paper finds that the products have been abused by criminals but that the incidence of such abuse and the amounts involved are low. The paper investigates possible weaknesses in the current system that allow limited criminal abuse to occur. It concludes with a number of guidelines that emerge from the study and are of value to regulators that wish to implement a similar system.

Originality/value – The South African AML/CFT scheme in relation to low-risk products is of interest to many international regulators that are grappling with the interplay between effective AML/CFT controls and the impact of strict controls on the ability of socially and economically excluded persons to access appropriate financial services. This paper provides evidence that appropriately designed controls can facilitate financial inclusion while limiting the risk of criminal abuse.

Identifying and managing low money laundering risk : perspectives on FATF's risk-based guidance

Purpose – The purpose of this paper is to investigate Financial Action Task Force (FATF)'s risk-based guidance to combat money laundering and terrorist financing to determine its approach to the identification and management of low-risk providers, products and transactions.

Design/methodology/approach – The paper analyses the relevant FATF recommendations and its guidance notes and reflects on key questions for regulators and financial institutions.

Findings – FATF has not defined “risk” for purposes of the risk-based approach. The absence of a clear definition complicates the identification of low-risk products. FATF do provide an example of a risk matrix that can be used to identify low-risk banks, but the example is based on assumptions and generalisations that are not sustainable. In addition, it identifies certain low-value transactions as “low risk” transactions. The paper reflects on the role of value as an indicator of risk and concludes with a number of suggestions to clarify the conceptual framework.

Originality/value – Low-risk products and transactions are often overlooked because the risk-based approach focuses attention on high-risk matters. Low-risk products are however crucial to the efforts to increase financial inclusion. The paper identifies gaps in the current conceptual framework and indicates ways in which they can be addressed.

Listed property trusts and downside systematic risk sensitivity

Purpose: This paper aims to identify and examine the determinants of downside systematic risk in Australian listed property trusts (LPTs).

Design/methodology/approach: Capital asset pricing model (CAPM) and lower partial moment-CAPM (LPM-CAPM) are employed to compute both systematic risk and downside systematic risk. The methodology of Patel and Olsen and Chaudhry et al. is adopted to examine the determinants of systematic risk and downside systematic risk.

Findings: The results confirm that systematic risk and downside systematic risk can be individually identified. There is little evidence to support the existence of linkages between systematic risk in Australian LPTs and financial/management structure determinants. On the other hand, downside systematic risk is directly related to the leverage/management structure of a LPT. The results are also robust after controlling for the LPTs' investment characteristics and varying target rates of return.

Practical implications: Investors and real estate analysts should conscious with the higher returns from high leverage and internally managed LPTs. Although there is no evidence that these higher returns are related to higher systematic risk, there could be the compensation for higher downside systematic risk.

Originality/value: This study provides invaluable insights into the management of real estate risk in Australian LPTs with implications for REITs in other countries. Unlike previous studies of systematic risk in REITs or LPTs, this is the first study to assess downside systematic risk and explore the determinants of downside systematic risk in LPTs.

The relationship between sustainability and the value of office buildings

There is an increasing body of evidence to suggest that the development of sustainability in office buildings and the acceptance of these buildings in the broader property market is increasing. However a gap still remains between the value of sustainability and the value of the building from an International Valuation Standards Committee (IVSC) definition of market value. Current literature is limited in the investigation of the impact of sustainable criteria on value component when undertaking a valuation of a commercial office building. Whilst substantial advances have been made in sustainable design and construction aspects, as well as reducing implementation costs and enhancing benefits associated with sustainability, there appears to be inherent barriers in adopting sustainability in the valuation process for the property industry.

This paper examines the limited previous research into the elements of sustainable criteria that impact upon property value, and in turn should be reflected in traditional valuation methods. The immaturity of the property market for sustainable building is such that current valuation methods do not appear to have significant evidential proof of increased property value through sales or lease evidence for sustainable buildings. Furthermore, this lack of market evidence makes it inherently difficult for valuers to assess the real market value of sustainable buildings through current valuation methodology. In other words, the level of risk associated with incorporating different levels of sustainability into office buildings appears difficult to measure using a market value perspective in today’s property market. Accordingly this paper examines current research that has been undertaken to identify particular sustainable criteria that potentially affects the value of a sustainable building. For example, previous research suggests that sustainable criteria impact upon the valuation equation through rental growth, depreciation, risk premium and cash flow. This paper also examines how other studies have viewed the impact of sustainable criteria and how they are weighted within the valuation equation. The discussion provides an insight into the rapidly evolving area of sustainability and office buildings with emphasis placed on the valuation process that seeks to assess a hypothetical purchaser’s perspective of this relationship.

Can the ABCD Score be dichotomised to identify high−risk patients with trainsient ischaemic attack in the emergency department?

Background: Recent evidence shows a substantial short-term risk of ischaemic stroke after transient ischaemic attack (TIA). Identification of patients with TIA with a high short-term risk of stroke is now possible through the use of the “ABCD Score”, which considers age, blood pressure, clinical features and duration of symptoms predictive of stroke.

Aim: To evaluate the ability of dichotomising the ABCD Score to predict stroke at 7 and 90 days in a population with TIA presenting to an emergency department.

Methods: A retrospective audit was conducted on all probable or definite TIAs presenting to the emergency department of a metropolitan hospital from July to December 2004. The ABCD Score was applied to 98 consecutive patients with TIA who were reviewed for subsequent strokes within 90 days. Patients obtaining an ABCD Score ≥5 were considered to be at high risk for stroke.

Results: Dichotomising the ABCD Score categorised 48 (49%) patients with TIA at high risk for stroke (ABCD Score ≥5). This high-risk group contained all four strokes that occurred within 7 days (sensitivity 100% (95% confidence interval (CI) 40% to 100%), specificity 53% (95% CI 43% to 63%), positive predictive value 8% (95% CI 3% to 21%) and negative predictive value 100% (95% CI 91% to 100%)), and six of seven occurring within 90 days (sensitivity 86% (95% CI 42% to 99%), specificity 54% (95% CI 43% to 64%), positive predictive value 12.5% (95% CI 5% to 26%) and negative predictive value 98% (95% CI 88% to 100%)). Removal of the “age” item from the ABCD Score halved the number of false-positive cases without changing its predictive value for stroke.

Conclusion: In this retrospective analysis, dichotomising the ABCD Score was overinclusive but highly predictive in identifying patients with TIA at a high short-term risk of stroke. Use of the ABCD Score in the emergency care of patients with TIA is simple, efficient and provides a unique opportunity to prevent stroke in this population of patients.

Laboratory and non-laboratory-based risk prevention models for secondary prevention of cardiovascular disease : the LIPID study

Aims : The aims of this study were to examine whether risk prediction models for recurrent cardiovascular disease (CVD) events have prognostic value, and to particularly examine the performance of those models based on non-laboratory data. We also aimed to construct a risk chart based on the risk factors that showed the strongest relationship with CVD.

Methods and results : Cox proportional hazards models were used to calculate a risk score for each recurrent event in a CVD patient who was enrolled in a very large randomized controlled clinical trial. Patients were then classified into groups according to quintiles of their risk score. These risk models were validated by calibration and discrimination analyses based on data from patients recruited in New Zealand for the same study. Non-laboratory-based risk factors, such as age, sex, body mass index, smoking status, angina grade, history of myocardial infarction, revascularization, stroke, diabetes or hypertension and treatment with pravastatin, were found to be significantly associated with the risk of developing a recurrent CVD event. Patients who were classified into the medium and high-risk groups had two-fold and four-fold the risk of developing a CVD event compared with those in the low-risk group, respectively. The risk prediction models also fitted New Zealand data well after recalibration.

Conclusion : A simpler non-laboratory-based risk prediction model performed equally as well as the more comprehensive laboratory-based risk prediction models. The risk chart based on the further simplified Score Model may provide a useful tool for clinical cardiologists to assess an individual patient's risk for recurrent CVD events.

Media reports of heroin overdose spates: public health messages, moral panics or risk advertisements?

This article reports on an investigation of the public health utility of media messages concerning spates (temporal clusters) of heroin-related overdose (HOD) from the perspective of some injecting drug users (IDUs). In-depth qualitative interviews were carried out with a convenience sample of 60 IDUs, in the setting of two Needle and Syringe Programs in an Australian regional city (Geelong) between April and May 2000. Very few interviewees reported that they had personally experienced a spate of overdoses. None of the interviewees reported communicating the existence of a killer batch to other IDUs. No interviewees reported having changed either their injecting practices or the amount of heroin they used following such a media alert. Indeed, a substantial minority of the interviewees reported seeking out these stronger batches and participant narratives illustrate that, for a substantial group of interviewees, the media reporting of a hypothetical 'killer batch' of heroin may have implications for their drug-seeking and health-related behaviour. It was found that the accuracy of information available to IDUs is mixed and that the flow of information within this social network was slow. Findings demonstrate that media reporting of killer batches of heroin has little value as a public health strategy and provide an example of how some activities that are proposed as public health measures may in fact have the opposite effect.

Risk allocation in public-private partnership projects

Both the increasing private participation in public projects and the critical importance of appropriate risk allocation to the success of public-private partnership (PPP) projects justify specific research on the risk allocation practice in PPP projects, particularly whether the practice is value-for-money driven. In this paper, the risk allocation in construction projects is examined firstly. The risks associated with PPP projects and the concept of optimal risk allocation are then reviewed. More importantly, the risk allocation practice in PPP projects is examined, particularly in the Australian context. Important issues, such as the current practice, the governments' accountability, and achieving efficient allocation, are discussed. The discussion presented in this paper is expected to justify and elicit further research on how to achieve efficient risk allocation in PPP projects

Exploring critical factors for achieving successful risk allocation in public-private partnership projects

Public Private Partnerships (PPP) as a procurement mechanism for infrastructure projects is becoming increasingly common. This is principally due to the value for money opportunities it offers the public sector sponsors. This value for money is primarily achieved through the optimisation of the allocation of risk inherent in the project being transferred from the public sector sponsors onto private sector bidders. This paper analyses the influence that these factors have on successful risk allocation with the aim of providing clearer parameters for optimal risk allocation in PPP projects. Through an extensive review of existing literature, the critical success factors for optimal risk allocation in PPP projects are identified. It is found that the optimisation of risk allocation in PPP projects is critically influenced by the identified factors, which will undoubtedly aid in the successful outcome for future PPP projects.

An agent-based approach to value theory and wealth distribution in economics

Any attempt to model an economy requires foundational assumptions about the relations between prices, values and the distribution of wealth. These assumptions exert a profound influence over the results of any model. Unfortunately, there are few areas in economics as vexed as the theory of value. I argue in this paper that the fundamental problem with past theories of value is that it is simply not possible to model the determination of value, the formation of prices and the distribution of income in a real economy with analytic mathematical models. All such attempts leave out crucial processes or make unrealistic assumptions which significantly affect the results. There have been two primary approaches to the theory of value. The first, associated with classical economists such as Ricardo and Marx were substance theories of value, which view value as a substance inherent in an object and which is conserved in exchange. For Marxists, the value of a commodity derives solely from the value of the labour power used to produce it - and therefore any profit is due to the exploitation of the workers. The labour theory of value has been discredited because of its assumption that labour was the only ‘factor’ that contributed to the creation of value, and because of its fundamentally circular argument. Neoclassical theorists argued that price was identical with value and was determined purely by the interaction of supply and demand. Value then, was completely subjective. Returns to labour (wages) and capital (profits) were determined solely by their marginal contribution to production, so that each factor received its just reward by definition. Problems with the neoclassical approach include assumptions concerning representative agents, perfect competition, perfect and costless information and contract enforcement, complete markets for credit and risk, aggregate production functions and infinite, smooth substitution between factors, distribution according to marginal products, firms always on the production possibility frontier and firms’ pricing decisions, ignoring money and credit, and perfectly rational agents with infinite computational capacity. Two critical areas include firstly, the underappreciated Sonnenschein-Mantel- Debreu results which showed that the foundational assumptions of the Walrasian general-equilibrium model imply arbitrary excess demand functions and therefore arbitrary equilibrium price sets. Secondly, in real economies, there is no equilibrium, only continuous change. Equilibrium is never reached because of constant changes in preferences and tastes; technological and organisational innovations; discoveries of new resources and new markets; inaccurate and evolving expectations of businesses, consumers, governments and speculators; changing demand for credit; the entry and exit of firms; the birth, learning, and death of citizens; changes in laws and government policies; imperfect information; generalized increasing returns to scale; random acts of impulse; weather and climate events; changes in disease patterns, and so on. The problem is not the use of mathematical modelling, but the kind of mathematical modelling used. Agent-based models (ABMs), objectoriented programming and greatly increased computer power however, are opening up a new frontier. Here a dynamic bargaining ABM is outlined as a basis for an alternative theory of value. A large but finite number of heterogeneous commodities and agents with differing degrees of market power are set in a spatial network. Returns to buyers and sellers are decided at each step in the value chain, and in each factor market, through the process of bargaining. Market power and its potential abuse against the poor and vulnerable are fundamental to how the bargaining dynamics play out. Ethics therefore lie at the very heart of economic analysis, the determination of prices and the distribution of wealth. The neoclassicals are right then that price is the enumeration of value at a particular time and place, but wrong to downplay the critical roles of bargaining, power and ethics in determining those same prices.

Rehabilitation : beyond the risk paradigm

Providing a succinct summary and critique of the scientific approach to offender rehabilitation, this volume for students of criminology, sociology and clinical psychology gives a comprehensive evaluation of both the Risk-Need-Responsivity Model and the Good Lives Model." "Rehabilitation is a value-laden process involving a delicate balance of the needs and desires of clinicians, clients, the State and the public. Written by two internationally renowned academics in rehabilitation research, this book argues that intervention with offenders is not simply a matter of implementing the best therapeutic technology and leaving political and social debate to politicians and policy-makers.