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Number Cruncher: The man behind the data at Ariadne Labs

Stu Lipsitz in front of an Ariadne Labs sign
Stu Lipsitz, Ariadne Labs Biostatistician

The name appears on hundreds of papers, dating back to the 1980s: Lipsitz S or Lipsitz SR. The papers’ subjects roam a wide landscape of medical and health topics: cancer, C-section rates, drug efficacy, and more. The name may not always be the lead author, but the lead authors will likely say that without the statistical mastery of Stu Lipsitz – Ariadne Labs’ biostatistician they would not have the crucial analysis of the raw data that underlie their conclusions. 

If you are an academic in medical research, chances are high that you have cited, or at least read, the work of Stu Lipsitz, even if you don’t realize it.  

The man behind the math is a genial statistics wizard who in conversation leaps from references to bar-coded surgical sponges to the TV show The Big Bang Theory to p-values. He constantly interrupts himself, like hyperlinks jolted to life, as he sees connections in what he just said. As a senior member of the lab’s Science and Technology platform, he works with every Ariadne program. “I’ve been at Ariadne Labs long enough that I probably talked to everyone at one time or another,” he acknowledged. 

“Stu has been a partner in Ariadne Labs from the very beginning,” said Atul Gawande, the lab’s co-founder. “He has been a critical contributor to every major trial, study, and data insight Ariadne Labs has made.”

Said Katherine Semrau, director of the lab’s BetterBirth Program, “Stu is always willing to pitch in and provide thoughtful analytic support to ‘let the data speak.’”

Additionally, Stu is the director of Biostatistical Services at the Center for Surgery and Public Health at Brigham and Women’s Hospital and a collaborative statistician in the hospital’s Division of General Internal Medicine. 

Nearly every person who works at Ariadne Labs has a favorite story about Lipsitz  and his gift of wresting key insights from raw data. Lipsitz has a few good stories about himself, too.  

Like the time in the 1990s when he attended a prestigious medical conference in which a researcher proudly made a presentation on a study of a new drug for advanced stomach cancer. Twenty patients who had only months to live were given the drug. “Nineteen of them almost died of the toxicity,” the researcher said. “In one patient, the tumor shrunk. We should look at this drug.”

That was too much for Lipsitz, then an assistant professor at the Harvard School of Public Health. “I got up and said, ‘I’m the biostatistician on this study. I can tell you right now that I don’t have to do any statistical tests on this data. If 19 of the patients almost died, this isn’t a treatment you want to try. That’s not something I would give anyone.’”

The incident proved to be good training for Lipsitz’s future work on Ariadne Labs’ Serious Illness Care program, which focuses on the tradeoffs facing patients at the end of life. 

The path to biostatistics 

Lipsitz is precise with facts. He’s even exact in areas such as the circumstances of his birth. “I was essentially born in Savannah, Georgia, but that’s because in my hometown, Beaufort, South Carolina, there wasn’t a gynecologist so my parents drove 45 miles away to Savannah to have me.” 

As Stu grew up, his family thought he would study medicine. “So I went to college thinking I’d be a doctor. When I almost passed out doing a dissection of a rat in biology class, I decided, ‘I don’t think I would be a good doctor. I’m not so excited about blood.’”  

Yet Stu was still interested in medicine, and began researching careers where he could be involved in the medical field, but with less blood. That search led him to biostatistics.

After receiving his bachelor’s degree in mathematics from the University of South Carolina, he earned a master’s degree in biostatistics from the University of North Carolina, Chapel Hill, and went on to pursue a doctorate in biostatistics at Harvard. He completed post-doctoral fellowships at Harvard School of Public Health and the Dana-Farber Cancer Institute. Soon after, he joined the Harvard School of Public Health as an assistant professor.

A focus on collaboration not competition

Lipsitz likens academia to The Big Bang Theory, a show that revolves around four young scientists/mathematicians jockeying for position at their universities. “People are fighting for grants, and publishing papers, saying, ‘My paper’s better than yours, I have the best paper.’” He once overheard a professor grousing when a fellow academic won a Nobel Prize for biostatistics and saying, “Well, he really didn’t have a good publication; he only had three publications that weren’t in great journals.” 

By contrast, Lipsitz is a collaborator by nature, and he also understands priorities in academics and in life. “It’s not all about the papers and grades,” he said. When his parents fell ill, he returned to South Carolina to care for them, taking a job at the Medical University of South Carolina. After they passed, he decided he really belonged in the North. In  2005, he joined the Brigham Division of General Medicine and Surgery, which had launched a new Center for Surgery and Public Health, run by an up-and-coming Atul Gawande.

“When people ask me how I came to Ariadne Labs, I say I came with the place because I was working with Atul when we could fill up this table with me, him, and two of his fellows. Looking back fondly at that time and comparing it to Ariadne now,  the four of us were kind of like Jeff Bezos and his team selling books out of his garage when he first  started Amazon.”  

Gawande recalled that time fondly. “I was lucky enough to recruit Stu from his home state of South Carolina. He was already a world-caliber statistical methods genius. And he is an amazing and wonderful teacher – to me as a brand new faculty member, to our students and fellows, to everyone. He will always find the time to help.” 

What Lipsitz loves even more than crunching numbers is figuring out what they signify. “I don’t play computer games,” he said. “My computer games are figuring out biostatistics, programming stuff, to see if my new statistical methods work…” And he is off on another tangent. 

A leading researcher at Ariadne Labs

Even in an organization like Ariadne Labs with many prolific researchers, Lipsitz publishes more papers than anyone else. He has played a key role in signature topics like surgical checklists and serious illness conversations. 

Lipsitz helped with Gawande’s  randomized study of how barcoding surgical sponges prevented them from being left in a patient during surgery. He played a key role in the initial studies of the Surgical Safety Checklist, starting with determining the sample size needed for validating its benefit. “We actually had a bigger drop in deaths than we were expecting,” he said. “So that was a fulfilling study.”

Lipsitz helped analyze data from the landmark BetterBirth Study in Uttar Pradesh, India, in which, contrary to expectations, the implementation of the Better Birth Checklist did not produce a measurable decrease in infant or maternal mortality rates. Lipsitz said, “That was hard after people put their heart and soul into it.” 

But Semrau, who led the study, remembers that “Stu’s approach and willingness to slice and dice the data in many ways provided deep insights to the null result.”  A major report on the BetterBirth Study, issued in June 2019, analyzed more than 200 million data points and provided an evidence base for key strategies to improve maternal health and childbirth rates globally. 

Once, after working on an operating room checklist, Lipsitz (who had just turned 50) suggested creating “The Midlife Crisis Checklist.” A sports car was first on the list. Needless to say, it was not developed, but Stu still laughs about it. 

Of Lipsitz’s many fortes, a chief one is accounting for “missing data.”  Say you’re looking at how well a doctor does by analyzing her patient visits. But a doctor’s sicker patients may not be able to visit as much. “That biases your study,” Lipsitz said. “So you try to follow up in a different way or use their previous visit to what we statisticians call ‘impute’ or estimate what they are currently doing.” Lipsitz’s techniques for accounting for missing data has proven invaluable in correctly interpreting results. 

However, “Even if the dataset that we are analyzing is complicated with missing data, which in turn requires a complex statistical method, we always want to present the result in a simple, understandable manner,” he said.

Lipsitz remains keenly aware that the numbers he crunches represent people’s lives. When he was working on cancer studies at Dana Farber, he would walk through the lobby and see the patients who would live or die validating — or invalidating — his studies. He realizes that incremental changes may indicate progress, but he always hopes for major impacts. And he has visions of what future cancer treatment might be like.  

“I think you need to have a chip in your body and when the first cancer cell goes off, the chip alarm rings and says, ‘This person has cancer developing.’ So I don’t know if that’ll ever happen and I wouldn’t know how to do it. That’s not my area. Steve Jobs didn’t design the iPhone or the iPad, but he had that vision. So sometimes you need someone to have the vision to do things.” 

If someone has the vision, Lipsitz will listen intently and then crunch the numbers to make it happen.

-Written by Stephanie Schorow