A Biostatistics Doctoral Student Finds Community at the Yale School of Public Health

Arriving at the Yale School of Public Health as a master’s student in biostatistics eight years ago, Yaqing Xu, MS ’16, PhD ’21, wasn’t sure how she would fit in.

Xu grew up in China and hadn’t ever been to the United States. She worried about how well she would be able to speak English, much less succeed in a daunting array of classes in statistics, epidemiology, and more. And even though she knew that she wanted to apply her expertise in math and statistical modeling to real-world problems, the future seemed difficult to imagine.

Her anxieties were short-lived once she settled in — with the help of a confidence-boosting high grade in her first-semester exam in computational statistics taught by Forrest Crawford, associate professor (biostatistics).

To be fair, she explained, that wasn’t the only thing that made her welcome to New Haven so warm. Small class sizes, easy friendships with fellow students, and exciting course material also helped.

But looking back after receiving her master’s and doctoral degrees from the Yale School of Public Health, it was that first sign of academic achievement that led to her earning both a master’s degree and a PhD in biostatistics.

Pursuing a PhD in Biostatistics

Summer work at the Yale Center for Analytical Sciences (YCAS) proved that she had made the right decision. She had to find a summer experience as a requirement for her degree, and while other classmates chose to work at pharmaceutical companies, she decided to use her time at YCAS to help decide between industry work or academia.

At YCAS, she helped Professor Denise Esserman (biostatistics), and physicians at Yale New Haven Children’s Hospital, determine how certain interventions changed the average length of stay for infants suffering from drug dependence — work that was featured on the front page of The New York Times — along with other important studies. She was a co-author of three publications that summer.

Collaborating with various professors on interesting projects “motivated me to pursue doctoral study,” she explained.

“A lot of times physicians are hypothesizing, and we have the tools to confirm those hypotheses. That’s really the key that I learned using statistics.”

Meanwhile, the transition to life in New Haven got easier. Long-term group projects helped to foster friendships with other classmates, which then grew deeper as she traded job tips and went on a fun apple-picking adventure. Dorm living helped, too, she said.

A Doctoral Student in Biostatistics

After applying to about 20 doctoral programs and visiting other campuses, continuing her studies in New Haven just made sense, she said.

“I met a lot of professors and students [at other schools], and I realized that what I had at Yale during my master’s was better than this,” she explained. “Once I got the offer from Yale, it took seconds to decide: I’m going to stay.”

The Department of Biostatistics encourages excellent methodological work that is motivated by sound science. As a doctoral student in biostatistics, Xu focused on developing statistical methods for interactions between genetics and the environment.

She tutored other YSPH students with coding in SAS and R languages for statistical and data analysis and provided counsel on their projects while also working as a teaching assistant.

She also tried industry work one summer, as her advisor, Professor Shuangge Steven Ma, interim department chair of biostatistics, said it would be a good way of gaining experience. With the help of the Office of Career Strategy, she prepared a resume and drilled mock interviews. After pitching herself through the Yale School of Public Health’s Career Management Center, interview requests came from all sorts of firms.

Ending up at a mid-sized pharmaceutical company in Cambridge, Mass. was enlightening. Xu used her statistical knowledge to help figure out if drugs were making an impact on brain tumors despite a small sample size of patients, and got a taste of real-world clinical trial methodologies.

One year later, she searched for work as a researcher in academia dealing with more common public health issues. But during the coronavirus pandemic, when a full-time job offer was rescinded, she turned to Ma for advice.

“He really encouraged me not to rush for a job. So I stayed at Yale for one more year. I think his support was very important,” she said.

Ma said that encouragement is a big part of his job — and that it’s one of the reasons why he’s so excited about the Ph.D. program.

“Yaqing is one of the many success stories we see,” Ma said. “Beyond gene-environment interactions, our students have also conducted cutting-edge research in a variety of fields. Our PhD program excels in fostering interdisciplinary collaboration between sciences and social sciences, in an effort to improve the impact of public health interventions on populations across the world.”

Xu’s doctoral research led to publications in Biometrics, Cancers, Genomics, and other prestigious journals. She is now an assistant professor at Shanghai Jiaotong University.

Xu said that she has a lot of people at Yale to thank for helping her get to this point in her career — including Hongyu Zhao, the Ira V. Hiscock Professor of Biostatistics, professor of genetics and professor of statistics and data science, as well as Melanie Elliot, administrative director of graduate student affairs.

“I’m really satisfied with my job in China,” Xu said. “But I want to emphasize all of these people who helped and supported me all the way.”