Yale School of Public Health (YSPH) alumna Dr. Ariel Chao, PhD ’24, MPH ’20, remembers fondly the moment her academic and professional aspirations became clear.
It was during a seminar by Dr. Donna Spiegelman, ScD, Susan Dwight Bliss Professor of Biostatistics, who was speaking passionately about the importance of implementation science and the critical need for new methodologies to translate research into real-life practice.
Chao said Spiegelman’s words resonated within her and she realized implementation science was a perfect way for her to combine her interests in statistical research and improving human health.
Chao recently capped off her academic pursuits by becoming the first PhD graduate of the Department of Biostatistics’ new Implementation and Prevention Science Methods Pathway. The pathway launched in 2020, the same year Chao obtained her MPH degree in biostatistics (BIS) and was looking for a PhD program to continue her studies.
“I feel very grateful and lucky that the program was available to me at the right time, and that I was able to successfully complete my PhD with the help of a strong support system at school and also at home,” she said. “I am honored to be the first PhD in Implementation Science at YSPH. I hope I am able to live up to the title!”
Spiegelman, founder and director of YSPH’s Center for Methods in Implementation and Prevention Science (CMIPS), was Chao’s primary PhD advisor; Laura Forastiere, associate professor of biostatistics, was co-advisor. Spiegelman said she is delighted that Chao is the first PhD grad, and that there are at least eight more students enrolled in the PhD pathway.
“The BIS Implementation Science Pathway is a centerpiece of our (CMIPS) programs,” she said. “It is a novel educational offering that exists nowhere else. We are excited to support students’ academic development as they emerge as young leaders in implementation science methods and strive to advance the field by addressing gaps in methodology with new innovations. Our students are eager to apply their new skills to critical public health problems such as cervical cancer and cardiovascular disease prevention, mental health promotion, HIV/AIDS, and environmental health, both here in the U.S. and around the world.”
I am honored to be the first PhD in Implementation Science at YSPH. I hope I am able to live up to the title!
Ariel Chao
Chao’s interest in biostatistics began when she was an undergraduate at UCLA, where she worked as a surgical database coordinator and clinical research coordinator. The experience helped her realize the field’s potential in transforming complex data into practical strategies.
Spiegelman said that, like many biostatistics graduate students, Chao was not a mathematics major and had to acquire new mathematical skills when she entered the program.
“Biostatistics is a mathematical discipline, and at the highest levels of research – methods development – requires the use of advanced mathematical and computational techniques,” Spiegelman said. “So, Ariel had to learn the aspects of mathematics and computing that she did not know, and in addition, learn the standard biostatistics and statistics topics.”
Chao was a quick learner.
“Ariel proved to be intelligent, hard-working, and persistent,” Spiegelman said. “This combination of qualities made it possible for her to excel – initially as an applied statistician, and subsequently, upon entering our PhD program in biostatistics, as a theoretical statistician.”
Chao said the core biostatistics courses certainly helped her build the needed analytical skills, but it was the program’s focus on details that proved especially valuable.
“More than the hard skills, I learned to be meticulous when checking the conditions required for validity of the analysis results,” she said. “Also, having worked with clinicians, social anthropologists, and health economists on various projects, I have come to understand the importance of working with a diverse team when solving problems.”
Chao said Spiegelman was a major influence on her decision to pursue her PhD at YSPH.
“Donna was the reason I wanted to continue my PhD at YSPH,” she said. “I was able to learn a lot from her, from statistical theory to the type of considerations needed to accurately draw inferences from study results.”
Spiegelman imparted her vast knowledge in the field of measurement error, an area of statistics that provides methods to reduce biases in estimates of health effects, as well as their uncertainty. This was essential as Chao began to study a topic in causal inference called spillover. This addresses the phenomenon that when people receive interventions –such as cervical cancer screenings and improvements to its delivery – they often share their experiences with others through word of mouth or on social media, and this results in increases in demand, uptake and, ultimately, overall population health.
Spiegelman said that this phenomenon is rarely measured, as there are limited statistical methods available to assess spillover impact. Chao’s PhD dissertation advanced the methodology, in a “particularly novel” way, Spiegelman said.
“She simultaneously accounts for the likely impact of mismeasurement of reported social networks and proposes methods to adjust for the bias in the estimates of spillover effects due to this mismeasurement,” said Spiegelman. “Typically, mismeasurement of social networks will lead to under-estimation of the spillover effects.”
During the latter half of her PhD pursuit, Chao worked closely with Forastiere, who is an expert in causal inference.
“Her passion in the field is very infectious, which made my PhD journey a very enjoyable experience despite its challenges,” Chao said. “In our weekly hour-long meetings, I was always able to have light-bulb moments after being inspired by our discussions. I am very grateful to Laura for the amount of time and commitment she made to help me improve my dissertation.”
Chao is currently working at Analysis Group in Los Angeles, where she is applying her biostatistics and implementation science training as an associate in health economics and outcome research. Her duties include protocol development for new studies, as well as data analysis to assess treatment safety and effectiveness.
“This job will allow me to apply my skills to health care effectiveness research,” she said. “I look forward to helping inform health care decisions, which was the reason why I had wanted to pursue a career in biostatistics in the first place.”
When asked what advice she would share with incoming MPH and PhD students, Chao said having a good group of friends who they can rely on and share moments together is key.
“YSPH really fosters a great sense of community, and I would encourage students to find their people, because I have learned so much from my friends,” she said. “I would also encourage students to keep an open mind for potential research directions to pursue, because I had come to YSPH with a specific topic in mind, but realized that the topic did not excite me as much as I thought it would, and eventually discovered something else that I was much more passionate about. And lastly, I would say to always find time to take a breather. The biostatistics program at YSPH is rigorous, and sometimes it could feel like we are drowning in work, but whenever I felt this way, I would take a walk around campus or watch a movie to allow my mind to rest, and oftentimes I was able to gain new ideas afterwards.”