Meet our multidisciplinary team of experts in health services research, data science, and population health analytics.
Prof. John Abisheganaden
MBBS (S'pore), MRCP (UK), M.Med (Int Med), FAMS, FRCP (Edin)
Director and Senior Consultant
Professor John Abisheganaden was appointed Director and Senior Consultant, HSOR on 1st October 2023. He holds a Fellowship from the Royal College of Physicians, Edinburgh UK; a MMED (Internal Medicine) from NUS Singapore, as well as a FAMS (Respiratory Med) from Academy of Medicine Singapore. He leads the HSOR team in population decision analytics and operations research, implementation and outcomes evaluation, as well as health system performance and sustainability. He is also Chair of NHG Respiratory Health Steering Committee, and the Medical lead for NHG Value-Based Care.
Dr Gary Ang Yee
MBBS, MPH, Dip (Family Med), GDMH, DIP (Family Practice Dermatology)
Consultant (Public Health)
Dr Ang Yee Gary obtained his MBBS from NUS (2006), MPH, NUS (2011), MBA (Dean List) from NTU (2024) and completed his public health residency in 2011. He received the Clinician Leadership in Research award in 2012, NHG CMTI Clinician Innovatory Preparatory Program in 2023 and has been a health services researcher since 2011. Currently, he is the Clinical Advisor to Heal Empowered by AI Launchpad (HEAL) as well as Consultant in Workplace Health. He has also been appointed as an academic editor for PLOS ONE in 2023. His recent projects are healthcare cost containment, chatbot for patient education in lung function test, improving treatment adherence via artificial intelligence and behavioural science, addressing modifiable risk factors in the workplace.
Email: gary.ang@nhghealth.com.sg
Dr Cheng San Chye
BSc (Hons), EdM, MSc, EdD (Doctor of Education)
Senior Principal Research Analyst
San Chye draws on quantitative and qualitative methods to generate insights that help to improve healthcare and foster better health. His current research focuses on the use of large language models and natural language processing to analyse unstructured clinical data. He holds a Doctor of Education and a Master of Science in Applied Statistics.
Eric Chua Siang Seng
BSc (Hons), (Business Management)
Senior Assistant Manager
Eric has worked on a variety of corporate events including the Annual Healthcare Humanity Awards, Senior Management Meetings as well as Board Retreats. Prior to joining NHG, he was an experienced Project Management and Marketing Specialist in Multinational Corporations for more than 7 years.
Gloria Ho
BA (Psychology), MPH
Senior Research Analyst
Gloria received her Master of Public Health from Imperial College London. Furthering her training and interest in health programme and service evaluation, she is working on various projects aimed at enhancing patient, organisation as well as system-level outcomes at HSOR. Prior to joining NHG, she was involved in the development and implementation of public communication strategies, including research, for national initiatives at the Ministry of Health.
Email: gloria.ho@nhghealth.com.sg
Ge Lixia
BMed (Nursing), MPH, MSc (Physiology)
Principal Research Analyst
Lixia is a health services researcher with close to 15 years of experience in nursing interventions, health programme evaluation, and population health research. Her work spans cancer nursing, community health, chronic disease management, frailty, and health activation. She has authored more than 15 first-author publications in reputable journals and received multiple awards in scientific competitions. Her research interests focus on instrument development and validation, health surveys, PROMs, longitudinal data analyses, mixed-method studies, and use of AI in HEOR.
Email: lixia.ge@nhghealth.com.sg
Jessica Widyawati
BSci (Hons) (Data Science and Economics)
Research Analyst
Jessica graduated from the inaugural cohort of the Data Science and Economics programme at NUS College of Humanities and Sciences, where she was part of the University Scholars Programme (now NUS College) that emphasised interdisciplinary education. Her cross-disciplinary background combines data science and economics with a focus on healthcare applications. Currently, Jessica handles stakeholder data requests and models blood glucose trajectories for newly developed Type 2 diabetes patients, with the goal of enabling early prevention of diabetic complications through data-driven insights.
Ernest Hoang
BComp (Hons)(CS)
Research Analyst
Ernest holds a Bachelor of Computer Science from NUS. He specializes in Software Development and Artificial Intelligence. He has experience in machine learning, prompt engineering, as well as cloud-native development. His recent projects include finetuning on Large Language Models (LLMs) for classification tasks, building an LLM-Math hybrid Commentary Generation Tool for Operations Dashboard, and deploying a chatbot on Amazon Web Service (AWS) in Synapxe’s Healthcare Commercial Cloud (HCC).
Email: cuong.hoang@nhghealth.com.sg
Brandon Loke
BSc (Hons) (Pharmacy), MSc (Computing)
Senior Research Analyst
Brandon is a registered pharmacist who holds a BSc (Pharmacy) with second major in Management from NUS, and a MSc Computing from Imperial College London. He is currently involved and interested in research on the use of large language models for analysis of unstructured clinical notes. Prior to joining NHG, he worked as a pharmacist at the Institute of Mental Health.
Dr Joseph Antonio D Molina
MD, MSc (Public Health)
Lead of Evaluation Science and Outcomes Research (ESOR)
Joseph is a medical doctor trained in epidemiology and public health. He leads a team of analysts at HSOR in evaluating health-related and economic outcomes of health programs and services in NHG. He holds a faculty position at the NTU Lee Kong Chian School of Medicine, and was a visiting faculty and centre director for the Joanna Briggs Institute (University of Adelaide) affiliate centre for health services management.
Dr Charmaine Krishnasamy
BOT (Hons), PhD
Principal Research Analyst
Charmaine currently contributes to health service evaluation projects. Her experience in health professions education includes better understanding feedback from students, clinicians and stakeholders to support the improvement of work and learning environments. Prior to joining NHG, she practised as an occupational therapist locally, and completed a series of research projects concerned with the occupations and community mobility needs of older persons in Singapore and Australia, and standardisation of an aspect of a driver assessment tool.
Dr Mary Lee
BA, MA (English Language), PhD (Communications)
Principal Research Analyst
Mary Lee is a qualitative researcher in population health and programme evaluation. Her projects include exploring the lived experiences of people managing chronic diseases and the psychosocial challenges that surround them; as well as evaluating the implementation of health services in hospital, community and home settings. She was involved in patient education and health professions education research previously, where much of her work centred on interprofessional collaboration. Her research has been published in Social Science & Medicine, International Wound Journal, Journal of Interprofessional Care and Discovering Social Science & Health among others.
Email: mary.cl.lee@nhghealth.com.sg
Dr Li Ruijie
Dip (Occupational Therapy), MSc (Occupational Therapy), PhD (Biostatistics)
Principal Research Analyst
RJ is a biostatistician with a PhD from King's College London and a clinical background in occupational therapy. Having practised in acute orthopaedic wards and community mental health and geriatric settings, he brings a first-hand understanding of healthcare delivery to his analytical work.
He was awarded a National Medical Research Council (NMRC) Research Training Fellowship to pursue his doctoral studies. His doctoral work developed new causal inference methods for sequential mediation estimating how treatments propagate their effects through chains of intermediate variables. His broader research applies causal reasoning to psychometrics, health economics, and population health measurement.
At NHG, RJ provides statistical consulting across the healthcare cluster, bridging the gap between clinical questions and rigorous analytical methods. He designed and secured funding for the Population Health Index study as principal investigator. He also evaluates clinical AI algorithms for cluster-wide deployment. He programmes in R, Python, and Stata, and maintains Linux-based data infrastructure.
Email: ruijie.li@nhghealth.com.sg
Dr Meng Fanwen
MSc (Operations Research), PhD (Operations Research)
Principal Research Analyst
Fanwen obtained his PhD in operations research (OR) from National University of Singapore (NUS), Singapore. He is currently Assistant Director and Principal Research Analyst at Nation Healthcare Group (NHG). Prior to joining NHG, he worked at NUS and University of Southampton of UK as senior research fellow and post-doc research fellow respectively on problems concerning operations planning and management in deterministic or uncertain environment. His recent research interests include health services research, hospital capacity planning and resource allocation, disease prevention and treatment using mathematical modeling, decision making and optimisation under uncertainty. He has been appointed as Associate Editor of Pacific Journal of Optimization since 2016. Some of his research work have been published in medical journals including Diabetes & Metabolism Journal, Journal of Sleep Research, Acta Diabetologica, Journal of the Royal Society Interface, Scientific Reports, Health Systems; and OR journals such as Operations Research, Mathematics of Operations Research, Annals of Operations Research, SIAM Journal on Optimization, Mathematical Programming.
Email: fanwen.meng@nhghealth.com.sg
Sheryl Ng Hui Xian
BSc (Hons) (Statistics), MPH
Senior Research Analyst
Sheryl H.X. Ng holds a Master of Public Health (Specialization in Epidemiology and Quantitative Methods) from the Saw Swee Hock School of Public Health (SSHSPH), National University of Singapore (NUS). Prior to joining NHG, she worked on Electronic Medical Record (EMR) data and provided statistical and public health expertise in the National University Health System (NUHS). She has also provided biostatistics support to research projects in SSHSPH on physical activity and stroke. Her research interests include longitudinal data analysis and health service utilization patterns of geriatric populations.
Ng Siok Leng
BBA (Hons), MEd, MSc (Statistics)
Assistant Director
Siok Leng started her career in NHG Health as the project manager for the Population Health Data Mart (PHDM), which is a multi-phase project to support NHG Health’s transformation journey in the Healthier SG (HSG) implementation. At HSOR, Siok Leng assists the Head of Data Science & Operations Research in leading the department to provide intelligence to facilitate evidence-based and data-driven decision-making in healthcare operations and resource planning. Prior to joining NHG Health, she was a trained educator and a lead assessment specialist. She was awarded the National Day Award (Commendation Medal) in 2019 and the COVID Resilience Medal (CRM) for her outstanding contributions to Singapore’s fight against the COVID-19 pandemic.
Dr Michelle Jessica Pereira
PhD, MPhty, BPhty (Hons I)
Principal Research Analyst
Michelle has a PhD in applied health economics. She is also a qualified physiotherapist, with postgraduate training (sports physiotherapy), who has practiced in a variety of settings in both Singapore and Australia. Her current portfolio at NHG-HSOR is focused on economic evaluations of health interventions for a variety of patient populations in Singapore.
Palvannan RK
BEng (Mechanical Engineering), MEng (Industrial & Systems Engineering)
Lead of Data Science and Operations Research (DSOR)
Palvannan has developed analytical decision models to support healthcare decision making. Starting from operations analysis and capacity planning (e.g. TTSH ICH beds), he has moved to MRSA disease modeling and population health analysis using databases. He is currently interested in using Large Language Models to increase productivity.
Palvinder Kaur
BSc (Biomedical Science), MPH
Principal Research Analyst
Palvinder leads research that strengthens care delivery, ranging from the evaluation of palliative and integrated care models to the implementation of prognostic tools that inform real‑world clinical decision‑making. Her work bridges epidemiology, statistics, mixed‑methods research, and implementation science to support policy translation and improve outcomes for patients with complex needs. Her research interests also include multimorbidity and heart failure, applying advanced analytics to understand disease clustering, trajectories, and patterns of healthcare cost and utilisation.
Christina Chieh Pann Pei
BSc (Biotechnology)
Senior Assistant Manager
Christina is involved in several community projects, and handles research related administrations in HSOR. Prior to her employment in NHG-HSOR, Christina worked as an Executive (Operations) and Research Assistant in various community healthcare related projects.
Dr Sun Yan
MSc (Medical Informatics), PhD (Machine Learning)
Senior Principal Research Analyst
Dr Sun Yan is a prolific researcher who has published extensively in peer-reviewed healthcare journals. She has secured multiple national grants for the development and evaluation of AI models in healthcare. Her current research focuses on the development and deployment of healthcare solutions leveraging AI and big data analytics, as well as cost-effectiveness evaluation of AI solutions using microsimulation.
Her work combines rigorous analytical methods with practical healthcare applications to improve patient outcomes and healthcare delivery efficiency.
Email: yan.sun@nhghealth.com.sg
Jasmine Tan Hwee Ling
Advanced Diploma in Business Administration
Senior Executive
As Senior Executive at HSOR, Jasmine oversees key operational functions across human resources, information technology, and accounting in HSOR. She provides dedicated executive support to the Head of Department, including coordinating management meetings and handling administrative matters. Drawing from over two decades of experience in multinational corporations, Jasmine brings deep expertise in accounting and administration to strengthen HSOR's operational capabilities.
Dr Aidan Lyanzhiang Tan
MBBS, MPH, GDOM
Consultant (Public Health)
Dr Tan is a public health specialist with graduate training in family medicine and occupational health. His work includes acute and chronic disease epidemiology and evidence synthesis. He also is involved in health programme and service evaluations.
Email: aidan.l.tan@nhghealth.com.sg
Teow Kiok Liang
BEng (Electrical Engineering), MSc (Industrial & Systems Engineering)
Senior Principal Research Analyst
Kiok Liang has worked on projects on the optimisation of hospital work processes for both outpatient and inpatient settings, and projections of national healthcare demands. He is on part time secondment to Ministry of Health. Prior to joining NHG, he was with the Defence Science & Technology Agency (DSTA). Kiok Liang’s key research interests include operations research, data mining, and health services planning.
Dr Yap Chun Wei
BSc (Pharm) (Hons), PhD
Senior Principal Research Analyst
Chun Wei has worked as a principal investigator on many clinical informatics projects, particularly in the areas of oncology and chronic kidney disease. He has experience with the development of clinical decision support tools to aid in the individualization of therapy. His current research interest is in predictive analytics. Prior to joining NHG, Chun Wei worked as an Assistant Professor in Department of Pharmacy, National University of Singapore.
Dr Yip Wan Fen
PhD (Ophthalmology), BSc (Hons) in Optometry
Principal Research Analyst
WanFen is a clinically trained optometrist (allied health) with PhD training in ophthalmology and ocular epidemiology (National University of Singapore). As a health services researcher, she focuses on research translation, aiming to accelerate the application of evidence into clinical practice to enhance patient care and health system outcomes. Her research and evaluation work spans across areas such as ophthalmology, chronic systemic diseases (hypertension, diabetes), and related target organ damage and mortality, palliative care, and strengthening community health resilience. Her notable publications include 1) Examining the Quality of Care Provided at Singapore's Primary Eye Care Model and Lessons Learned to Maintain Quality Care-Mixed-Methods Study, 2) Building community resilience beyond COVID-19: The Singapore way, 3) Evaluation of the SLS CHARTER care model to support post-stroke care continuity and employment, 4) Unravelling ChatGPT's potential in summarising qualitative in-depth interviews.
Email: wan.fen.yip@nhghealth.com.sg
Dr Zhu Zhecheng
MSc (Information Engineering), PhD (Industrial & System Engineering)
Senior Principal Research Analyst
Zhecheng holds a PhD in Industrial & Systems Engineering from NUS. His research area is applied optimisation and discrete event simulation. He has project experience in patient flow simulation, appointment scheduling, workload projection and data visualization, etc.
A Manohari
Bsc (Biomedical Sciences), MPH (Public Health)
Research Analyst
Manohari holds a Master of Public Health from Lund University, Sweden. Prior to joining NHG, she worked for two years at the National University Health System (NUHS) with the neurology team, managing various clinical trials. Drawing on her clinical research experience and public health expertise, she conducts programme evaluation studies at HSOR to support improvements in healthcare quality and effectiveness.
Email: a.manohari@nhghealth.com.sg
Rachel Chia Sher Li
Bsc (Life Sciences), Msc (Translational Medicine)
Research Analyst
Rachel completed her Master of Science (Research) at the National University of Singapore, where she studied biomarkers of neuroinflammation and cerebral vascular function in cognitive impairment. Her research interests focus on translating findings into clinical applications. At NHG-HSOR, she conducts both individual programme assessments and portfolio impact assessments to evaluate healthcare utilisation and patient outcomes across multiple programmes.
Dr Sherry Shuya Lu
BA (Sociology, Education), MA (Social Science), PhD (Sociology and Anthropology)
Senior Research Analyst
Sherry is a sociologist and demographer graduated from NUS (PhD) and University of California, Irvine (BA and MA). In her previous roles at NUS and A*STAR, she worked extensively with the Singapore Longitudinal Early Development Study (SG-LEADS) dataset, examining immigrant families, health disparities, and maternal-children psychological wellbeing. Her research interests include population health, demographic transitions, and the social determinants of health.
Email: lu.shuya@nhghealth.com.sg
Tan Yong Yi
BSc (Hons) Life Sciences, MPH (in progress)
Research Analyst
Yong Yi holds a Bachelor of Science (Honours) in Life Sciences with a specialisation in Biomedical Sciences from the National University of Singapore. She is currently pursuing a Master of Public Health, with broad research interests in various public health topics.
Email: tan.yong.yi@nhghealth.com.sg
