James P. Thompson

Strategies for antiviral stockpiling for future influenza pandemics: a global epidemic-economic perspective.

Influenza pandemics present a global threat owing to their potential mortality and substantial economic impacts. Stockpiling antiviral drugs to manage a pandemic is an effective strategy to offset their negative impacts; however, little is known about the long-term optimal size of the stockpile under uncertainty and the characteristics of different countries. Using an epidemic–economic model we studied the effect on total mortality and costs of antiviral stockpile sizes for Brazil, China, Guatemala, India, Indonesia, New Zealand, Singapore, the UK, the USA and Zimbabwe. In the model, antivirals stockpiling considerably reduced mortality. There was greater potential avoidance of expected costs in the higher resourced countries (e.g. from

Implications of long-term care capacity response policies for an aging population: A simulation analysis

55 billion to

Future living arrangements of Singaporeans with age-related dementia

27 billion over a 30 year time horizon for the USA) and large avoidance of fatalities in those less resourced (e.g. from 11.4 to 2.3 million in Indonesia). Under perfect allocation, higher resourced countries should aim to store antiviral stockpiles able to cover at least 15 per cent of their population, rising to 25 per cent with 30 per cent misallocation, to minimize fatalities and economic costs. Stockpiling is estimated not to be cost-effective for two-thirds of the worlds population under current antivirals pricing. Lower prices and international cooperation are necessary to make the life-saving potential of antivirals cost-effective in resource-limited countries.

Dynamic Knowledge, Organizational Growth, and Sustainability: The Case of Prestwick Memory Devices

INTRODUCTION The demand for long-term care (LTC) services is likely to increase as a population ages. Keeping pace with rising demand for LTC poses a key challenge for health systems and policymakers, who may be slow to scale up capacity. Given that Singapore is likely to face increasing demand for both acute and LTC services, this paper examines the dynamic impact of different LTC capacity response policies, which differ in the amount of time over which LTC capacity is increased, on acute care utilization and the demand for LTC and acute care professionals. METHODS The modeling methodology of System Dynamics (SD) was applied to create a simplified, aggregate, computer simulation model for policy exploration. This model stimulates the interaction between persons with LTC needs (i.e., elderly individuals aged 65 years and older who have functional limitations that require human assistance) and the capacity of the healthcare system (i.e., acute and LTC services, including community-based and institutional care) to provide care. Because the model is intended for policy exploration, stylized numbers were used as model inputs. To discern policy effects, the model was initialized in a steady state. The steady state was disturbed by doubling the number of people needing LTC over the 30-year simulation time. Under this demand change scenario, the effects of various LTC capacity response policies were studied and sensitivity analyses were performed. RESULTS Compared to proactive and quick adjustment LTC capacity response policies, slower adjustment LTC capacity response policies (i.e., those for which the time to change LTC capacity is longer) tend to shift care demands to the acute care sector and increase total care needs. CONCLUSIONS Greater attention to demand in the acute care sector relative to demand for LTC may result in over-building acute care facilities and filling them with individuals whose needs are better suited for LTC. Policymakers must be equally proactive in expanding LTC capacity, lest unsustainable acute care utilization and significant deficits in the number of healthcare professionals arise. Delaying LTC expansion could, for example, lead to increased healthcare expenditure and longer wait lists for LTC and acute care patients.

Consulting approaches with system dynamics: three case studies

BACKGROUND With rapid aging, Singapore faces an increasing proportion of the population with age-related dementia. We used system dynamics methodology to estimate the number and proportion of people with mild, moderate, and severe dementia in future years and to examine the impact of changing family composition on their likely living arrangements. METHODS A system dynamics model was constructed to estimate resident population, drawing birth and mortality rates from census data. We simulate future mild, moderate, and severe dementia prevalence matched with estimates of total dementia prevalence for the Asian region that includes Singapore. Then, integrating a submodel in which family size trends were projected based on fertility rates with tendencies for dependent elderly adults with dementia to live with family members, we estimate likely living arrangements of the future population of individuals with dementia. RESULTS Though lower than other previous estimates, our simulation results indicate an increase in the number and proportion of people in Singapore with severe dementia. This and the concurrent decrease in family size point to an increasing number of individuals with dementia unlikely to live at home. CONCLUSIONS The momenta of demographic and illness trends portend a higher number of individuals with dementia less likely to be cared for at home by family members. Traditions of care for frail elderly found in the diverse cultures of Singapore will be increasingly difficult to sustain, and care options that accommodate these demographic shifts are urgently needed.

Stakeholders’ perspective on issues and challenges associated with care and treatment of aging-related cognitive impairment disorders in Singapore

System dynamics methodology and knowledge management can be integrated to enable managers to design and implement better policies for achieving sustainable organizational states. A system dynamics approach was used at a large manufacturing firm to address a critical sustainability issue. A decision maker and system dynamics consultant were interviewed to discover how the decision makers understanding of the sustainability issue changed as a consequence of the consulting engagement. Our research reports that the engagement led to better understanding of sustainability issues and to improved stewardship of corporate assets and the environment. We propose the use of a knowledge management tool to further learning and offer six points to consider in future efforts aimed at assessing learning developed in a system dynamics consulting engagement with sustainability as a core issue.

Precise modeling of aging populations

Although the most obvious characteristic of system dynamics is often the computer simulation model, it is not always that way. From my experience, the valuable lessons from the methodology are obtained from crisp logic and sound reasoning supported by a simulation model. In this paper I discuss approaches to client issues and how to assess the clients capacity to solve problems with system dynamics. Three case studies illustrate how consultants assessed our clients willingness and preparedness and how we employed system dynamics based on that assessment. Here, the methodologys most obvious characteristic is desirable and lasting results. Copyright

Critical Learning Incidents in system dynamics modelling engagements

BACKGROUND An expanding elderly population poses challenges for the provision of care and treatment for age-related physical and mental disorders. Cognitive impairment (CI)/dementia is one such mental disorder that is on the rise in Singapore and has concomitant implications for social and health systems. The objective of this study is to understand the perspectives of prominent stakeholders about current and future issues and challenges associated with CI/dementia among the elderly in Singapore. METHODS Using indepth interviews, this qualitative study obtained the views of multiple stakeholders on issues and challenges associated with CI/dementia in Singapore. The 30 individuals interviewed as part of the study included clinicians, policy-makers, researchers, community workers, administrators, and caregivers. Using a framework approach, interview texts were indexed into domains and issues by utilizing NVivo 9.0 software. RESULTS The stakeholders expressed concerns related to multiple domains of the CI/dementia care system: attitude and awareness, economics, education, family caregiving, inputs to care system, living arrangements, prevention, screening and diagnosis, and treatment and management of care. Within each domain, multiple issues and challenges were identified by respondents. CONCLUSIONS The study identifies a complex set of inter-related issues and challenges that are associated with the care and treatment of people with CI/dementia. The results suggest that CI and dementia profoundly affect patients, families, and communities and that the issues related to the two disorders are truly system-wide. These findings lay the foundation for utilization of a systems approach to studying CI/dementia and provide an analytic framework for future research on complex health care issues.