Adapting a Markov Monte Carlo simulation model for forecasting the number of Coronary Artery Revascularisation Procedures in an era of rapidly changing technology and policy

<p>Abstract</p> <p>Background</p> <p>Treatments for coronary heart disease (CHD) have evolved rapidly over the last 15 years with considerable change in the number and effectiveness of both medical and surgical treatments. This period has seen the rapid development and uptake of statin drugs and coronary artery revascularization procedures (CARPs) that include Coronary Artery Bypass Graft procedures (CABGs) and Percutaneous Coronary Interventions (PCIs). It is difficult in an era of such rapid change to accurately forecast requirements for treatment services such as CARPs. In a previous paper we have described and outlined the use of a Markov Monte Carlo simulation model for analyzing and predicting the requirements for CARPs for the population of Western Australia (Mannan et al, 2007). In this paper, we expand on the use of this model for forecasting CARPs in Western Australia with a focus on the lack of adequate performance of the (standard) model for forecasting CARPs in a period during the mid 1990s when there were considerable changes to CARP technology and implementation policy and an exploration and demonstration of how the standard model may be adapted to achieve better performance.</p> <p>Methods</p> <p>Selected key CARP event model probabilities are modified based on information relating to changes in the effectiveness of CARPs from clinical trial evidence and an awareness of trends in policy and practice of CARPs. These modified model probabilities and the ones obtained by standard methods are used as inputs in our Markov simulation model.</p> <p>Results</p> <p>The projected numbers of CARPs in the population of Western Australia over 1995–99 only improve marginally when modifications to model probabilities are made to incorporate an increase in effectiveness of PCI procedures. However, the projected numbers improve substantially when, in addition, further modifications are incorporated that relate to the increased probability of a PCI procedure and the reduced probability of a CABG procedure stemming from changed CARP preference following the introduction of PCI operations involving stents.</p> <p>Conclusion</p> <p>There is often knowledge and sometimes quantitative evidence of the expected impacts of changes in surgical practice and procedure effectiveness and these may be used to improve forecasts of future requirements for CARPs in a population.</p

Using a Markov simulation model to assess the impact of changing trends in coronary heart disease incidence on requirements for coronary artery revascularization procedures in Western Australia

<p>Abstract</p> <p>Background</p> <p>The population incidence of coronary heart disease (CHD) has been declining in Australia and many other countries. This decline has been due to reduced population levels of risk factors for CHD and improved medical care for those at higher risk of CHD. However, there are signs that there may be a slowing down or even reversal in the decline of CHD incidence due to the 'obesity epidemic' and other factors and this will have implications for the requirements for surgical treatments for those with CHD.</p> <p>Methods</p> <p>Using a validated Markov simulation model applied to the population of Western Australia, different CHD incidence trend scenarios were developed to explore the effect of changing CHD incidence on requirements for coronary artery bypass graft (CABG) and percutaneous coronary interventions (PCI), together known as coronary artery revascularization procedures (CARPs).</p> <p>Results</p> <p>The most dominant component of CHD incidence is the risk of CHD hospital admission for those with no history of CHD and if this risk leveled off and the trends in all other risks continued unchanged, then the projected numbers of CABGs and PCIs are only minimally changed. Further, the changes in the projected numbers remained small even when this risk was increased by 20 percent (although it is an unlikely scenario). However, when the other CHD incidence components that had also been declining, namely, the risk of CABG and that of CHD death for those with no history of CHD, were also projected to level off as these were declining in 1998-2000 and the risk of PCI for those with no history of CHD (which was already increasing) was projected to further increase by 5 percent, it had a substantial effect on the projected numbers of CARPs.</p> <p>Conclusion</p> <p>There needs to be dramatic changes to several CHD incidence components before it has a substantial impact on the projected requirements for CARPs. Continued monitoring of CHD incidence and also the mix of initial presentation of CHD incidence is required in order to understand changes to future CARP requirements.</p

Assessing the impact of reducing risk factors for cardio-vascular disease in Thailand.

Cardiovascular disease (CVD) is a global health problem and there has been an epidemiological transition of CVD from high income countries to low-middle income countries. In the case of Thailand, the prevalence of heart disease and stroke is increasing. In order to reduce the risk of CVD, the Ministry of Public Health in Thailand has implemented a number of primary CVD prevention strategies within the last decade. These strategies are being specifically implemented to address the future potential economic burden of increasing CVD. However, the economic impact of reducing multiple risk factors, at a population level in Thailand, in terms of health care costs is unclear. In order to plan for investment in public health interventions within finite resources, it is imperative that decision makers have sufficient information to identify the target populations and risk reduction strategies, and to assess the impact of these strategies on the population.This study aims to estimate the future prevalence of CVD in Thailand over the next 5-10 years and the potential economic and health benefits of strategies to reduce the population risk factors during this period.The mathematic CVD cost-offset model has been developed in this study in 7 stages. 1) Descriptive analysis of the CVD risk profile data from the 4th National Health Examination Survey (NHESIV) 2008-2009 data set in order to explore the association of CVD risk factors in Thailand. 2) Calculate the probability of future CVD event which applies the CVD risk prediction equation. 3) Estimate of the number of future CVD events. 4) Validation of the estimated number of annual CVD event with the actual CVD hospitalisation event in Thailand. 5) Calculate the cost of hospital admission due to CVD from the Universal Coverage Health Care Scheme (UC) data in 2009. 6) Estimate the burden of CVD in terms of the DALYs. 7) Estimate the impact of reducingCVD risk factors in different scenarios. The study outcomes being the number of hospitalisation cost savings, number of premature death savings, DALY savings and health care cost savings. The outcomes will also account for the uncertainty analysis.As indicated above, no studies currently exist that focus specifically on the mathematic model for estimating the future situation of CVD in Thailand. Therefore, this study represents an original contribution to that knowledge. The findings of this study will contribute to health policy by providing specific new knowledge and information regarding Thai CVD risk factors and the impact of the risk reduction which will assist health policy makers in the planning and future investment in prevention programs for CVD in Thailand. Moreover, it is expected that the finding from this research will establish a CVD prediction model for Thailand, and one which may be applicable and compatible to the Asia and Pacific regions