It takes a village to raise a child — or to get through a PhD programme for that matter. For Dr Chen Yirong, that village included her supervisor at the NUS Saw Swee Hock School of Public Health (SSHSPH). She was a mother of one when she embarked on the programme in 2014, with another child coming onboard during her second year. Now, having attained her PhD in Public Health (Biostatistics), she is even more aware of the importance of everyone chipping in to make things a success.
“I was very lucky to have an understanding supervisor during my PhD, and great support from my husband to share some of the burden. As a mother, you naturally want to give the best to your children and at the same time, being in the field of public health research, we do have a chance to make it a better place for everyone,” explained Dr Chen.
Dr Chen’s interest and concern for public health inspired her studies into infectious diseases like dengue and Hand, Foot and Mouth Disease (HMFD). As an undergraduate at NUS Science, Dr Chen majored in Statistics and Economics, graduating with first class honours. While most of her peers chose to specialise in Finance and Business Statistics, she remained on the generalist track until her final year project piqued her interest in research.
After graduating, Dr Chen started out as a Research Assistant at SSHSPH under its Vice Dean, Research and Domain Leader (Biostatistics & Modelling) Associate Professor Alex R Cook. The work allowed her to combine her background in statistics and her passion for public health. It also formed the basis for Dr Chen’s PhD research constructing statistical models for infectious diseases to inform control policies and measure their efficacy.
Dr Chen developed spatial forecasting methods for dengue in collaboration with the National Environment Agency (NEA) that are now being adapted for routine use. All four strains of the mosquito-borne dengue virus are endemic to Singapore, with frequent localised outbreaks occasionally leading to national epidemics. Dr Chen’s research showed that the forecasting algorithm made it possible to predict the number of cases in a neighbourhood to a high level of accuracy.
Explaining the impact of her findings, Dr Chen said, “Dengue has always been a big public health problem for Singapore and there has been sizable economic burden due to dengue… We have now managed to forecast the risk of dengue a few weeks ahead for NEA to plan their resources to target at the high-risk areas for efficiency.”
The biostatistician also worked with the Ministry of Health (MOH) to assess the efficacy of the policy of preschool closures to prevent HMFD outbreaks. Using data from nearly 200,000 cases of HFMD over the period of a decade, Dr Chen and her colleagues conducted a retrospective analysis to determine the effects of the policy of school closures due to institutional outbreaks of the disease. They found that while school closures were associated with a reduction in the transmission rate of HFMD, the effect is relatively small relative to the burden on families, and may not justify the routine use of school closures in HFMD outbreaks. In light of Dr Chen and her colleagues’ findings, MOH has relaxed this policy.
Going forward, Dr Chen hopes to continue using her knowledge and experience in modelling endemic diseases to make a difference to public health in Singapore. “It is really something small compared to big topics like global burden of diseases. But I feel one way to approach public health is really just to start with things around you, from what you can do to improve people’s lives,” she said.