Five questions for … Dr. Stanley Xu

Dr. Stanley Xu is a senior research scientist biostatistician in the Division of Biostatistics Research in the Department of Research & Evaluation. He has served as principal investigator, co-investigator, and lead biostatistician on randomized trials and observational studies funded by the National Institutes of Health, Agency for Healthcare Research and Quality, Centers for Disease Control and Prevention, and the U.S. Food and Drug Administration. He has contributed to studies of vaccine safety, substance abuse, cardiac outcomes, diabetes, hypertension, pharmacoepidemiology, health care utilization, heath care disparities, social needs, mental health, prediction models, and surveillance of the COVID-19 pandemic.

Please tell us a little about your background and why you joined Research & Evaluation.

I immigrated to the United States from China in the early 1990s and worked as a fellow in biology labs until 1997. Immediately after obtaining a PhD in Biostatistics from University of Colorado in 2001, I joined the Institute for Health Research (IHR) at Kaiser Permanente Colorado as a statistician and investigator. In my 19 years at IHR, I got to know people from R&E, including former senior director Dr. Steven Jacobsen, scientists, and research staff. I admired them and enjoyed our collaborations. I had been thinking of applying for a scientist position at R&E in recent years. I am glad that I applied in 2019 and was able to join R&E in June 2020.

In your short time here, you have published some research with important insights into the COVID-19 pandemic, most recently, a study on mortality and COVID-19 vaccines. What led you to pursue that subject and what was the most important thing you found?

Vaccines have prevented the spread of contagious, dangerous, and deadly diseases. Since March 2020, in the early days of the COVID-19 pandemic, scientists worldwide raced to find effective and safe vaccines. However, safety concerns about these fast-tracked vaccines could hinder their adoption by the public. The CDC selected the vaccine safety team at R&E to evaluate the association between COVID-19 vaccination and mortality.

I am pleased to lead this 3-year study and work with the wonderful team. We are happy with the recent publication titled “COVID-19 Vaccination and Non–COVID-19 Mortality Risk — Seven Integrated Health Care Organizations, United States, December 14, 2020–July 31, 2021” in MMWR. Our study has shown that there was no increased risk for mortality among COVID-19 vaccine recipients. This finding reinforces the safety profile of currently approved COVID-19 vaccines in the United States. The study has attracted worldwide media attention due to its significant implication in public health. The surveillance of mortality risk after COVID-19 vaccination is ongoing. We will adjust for individual-level risk factors and incorporate causes of deaths in future analyses.

You also published a paper on the impact of the COVID-19 pandemic on health care utilization. What was the takeaway from that?

That study assessed how health care utilization in Kaiser Permanente Southern California changed due to the pandemic. We found that in-person visits dropped dramatically during the early period of the pandemic, but there was a corresponding increase in telehealth visits during the same period. By the end of June 2020, the combined outpatient and telehealth visits had recovered to pre-pandemic levels. Kaiser Permanente Southern California delivered much-needed care to our members via telehealth services during the pandemic.

What is next on your research horizon?

Beside vaccine safety research, I have been collaborating with investigators from the Kaiser Permanente Colorado Region on opioid prescription and overdose. I led the development of a novel method for assessing the risk of tapering opioid doses by defining exclusive opioid use patterns for each patient. A clinical paper and a method paper are under development.

When you are not at work, how do you like to spend your spare time?

I enjoyed playing basketball with my friends before the pandemic (I was a decent 3-point shooter). Since the pandemic started in March 2020, I have been playing tennis. Sometimes my wife and I team up to play doubles with our neighbor couples. My family also likes to travel.

Image: Dr. Xu in New York’s Times Square in 2018