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John Pastor Ansah

Assistant Professor


Contact: 66011215

Dr John P. Ansah is an Assistant Professor of the Programme in Health Services and Systems Research, Duke-NUS Medical School and a faculty fellow at Residential College 4, National University of Singapore.

His recent work includes modelling the trajectory of the Covid-19 outbreak in Singapore, to understand how different interventions (such as containment, social distancing and attainment of herd immunity) may impact on the community spread of COVID-19 in Singapore.  The study uses Susceptible-Exposed-Infectious-Recovered (SEIR) model to simulate the dynamics of COVID-19 infection, accounting for the impact of asymptomatic infections.

Asst Prof Ansah holds a PhD degree in Systems Science methodology of System Dynamics, and has 10 years’ experience in the application of simulation modelling to complex health policy issues. His research uses computational modelling—with systems thinking and System Dynamics methodology as the foundation—coupled with the active involvement of stakeholders to better understand complex health systems issues to inform policy and interventions to improve health outcomes. His research interests lie broadly in the area of health systems improvement—to address strategic and operational health and social care challenges – and the evaluation of health system-wide impacts of complex health and social care interventions. Current projects includes long-term care needs, resilience and hip fracture recovery trajectories among the elderly, patients flow in the emergency department, enhanced primary care for an ageing society and human resources for health.

Research Team

Aloysius Chia
Research Associate

  1. Nipaporn Urwannachotima, Piya Hanvoravongchai, Piyada Prasertsom, Victoria Koh and John P. Ansah (2019). Sugar-sweetened beverage tax and potential impact on dental caries in Thai adults: An evaluation using the Group Model Building Approach. Systems Research and Behavioral Science, 36(1), 87-99.
  2. Nipaporn Urwannachotima, Piya Hanvoravongchai and John P. Ansah (2019). System Dynamics analysis of dental caries status among Thai adults and elderly.Journal of Health Research. DOI: 10.1108/JHR-05-2019-0097
  3. John P. Ansah, Ryan H.I. Leung, Salman Ahmad (2019). An Evaluation of the Impact of Aggressive Hypertension, Diabetes and Smoking Cessation Management on CVD outcomes at the Population Level: A Dynamic Simulation Analysis.  BMC Public Health, 19(1), 1105. DOI: 10.1186/s12889-019-7429-2
  4. John P. Ansah, Victoria Koh, Dirk De Korne, Thiyagarajan Jayabaskar, David B. Matchar, Desmond Quek. (2019) Modeling manpower requirement for a population with changing healthcare needs: the case of ophthalmic nurses and allied health ophthalmic professionals. Health Policy and Technology, 8(3), 282-295.
  5. John P. Ansah, Amina Islam, Victoria Koh, Vanthy Ly, Hero Kol, and David Matchar. (2019). Systems modelling as an approach for understanding and building consensus on non-communicable disease management in Cambodia. BMC Health Services Research, 19(1), 1-10. DOI: 10.1186/s12913-018-3830-2
  6. David B. Matchar, John P. Ansah, Victoria Koh and Heather E. Whitson (2018). Trajectories of functional ability over the life course: a dynamic model of the interactions of stressor-induced functional loss and resilience. System Dynamics Review, 34(4), 481-502.
  7. Nipaporn Urwannachotima, Piya Hanvoravongchai and John P. Ansah (2018). Sugar-sweetened beverage tax and potential impact on dental caries in Thai adult: An evaluation using the Group Model Building approach. Systems Research and Behavioral Science, 36(1), 87-99.
  8. John P. Ansah, David Matchar, Victoria Koh and Lukas Schoenenberger (2018). Mapping the dynamic complexity of chronic disease care in Singapore using group model building in knowledge elicitation. Systems Research and Behavioral Science, 35(6), 759-775. DOI: 10.1002/sres.2517
  9. John P. Ansah, Dirk De Korne, Steffen Bayer, Pan Chong, Thiyagarajan Jayabaskar, David B. Matchar, Nicola Lew, Andrew Phua, and Desmond Quek (2018). Projection of Eye Disease Burden in Singapore. Annals Academy of Medicine Singapore, 47(1), 13-28. PMID: 29493707
  10. John P. Ansah, Chi-Tsun Chiu, Victoria Koh, Choy-Lye Chei, Yi Zeng, Zhao-Xue Yin and David B. Matchar (2017). Projecting the number of people with cognitive impairment in China using a multi-state dynamic population model. System Dynamics Review, 33(2), pp 89-111.