Stephen Lagakos, talented biostatistician with a common touch

“We invited them back to our offices and planned the Woburn study right on the spot,’’ Marvin Zelen, the Lemuel Shattuck research professor of statistical science at the Harvard School of Public Health, said of their work linking water from the wells to illnesses such as leukemia that were affecting children in the city. “Steve did all the heavy lifting and was absolutely terrific. That study was done a long time ago, but to this day it’s the most innovative one ever done on the environment. And it was all Steve’s clever ideas.’’

Dr. Lagakos was driving in Peterborough, N.H., on Monday, near his summer home in Rindge when his car collided with another on Route 202. He died in the crash, along with his wife, Regina, and his mother, Helen, whose 94th birthday they were celebrating. He was 63 and had been living in Wellesley.

Dr. Lagakos “was at the very zenith of the profession,’’ said Victor De Gruttola, who chairs the biostatistics department at the School of Public Health. “He worked at the highest level of biostatistics.’’

And yet, Dr. Lagakos had a personal touch throughout his career that allowed him to converse easily with those whose grasp of math may have ended with high school.

“In all my workings with him, and there were many, he never made lay people feel as if they didn’t know what they were talking about,’’ said the Rev. Bruce A. Young, the former pastor of Trinity Episcopal Church in Woburn and the cofounder of the citizens group, For a Cleaner Environment, or FACE.

“He always could find something in what we were saying that he held as important and insightful,’’ Young said. “That was a tremendous gift. He was upholding us, and when I say us, I mean the community in Woburn in our attempts to get at the truth.’’

The truths Dr. Lagakos sought ranged from Woburn’s wells to research for the Dana-Farber Cancer Institute to finding new ways to lower the transmission rate of HIV from pregnant women to their fetuses.

“His seminal contributions to the field of AIDS research helped provide crucial statistical foundations upon which we could better combat this terrible disease,’’ Julio Frenk, dean of the Harvard School of Public Health, said in a statement issued yesterday.

“When the AIDS epidemic was beginning to be noticed, he organized a center to study its quantitative aspects,’’ Zelen said. “Steve was instrumental in designing many of the clinical trials nationwide to find therapies for treating AIDS, and he was absolutely fundamental to the AIDS program in the world.’’

Born in Philadelphia, Stephen Lagakos was the son of a Greek immigrant and grew up in a household where extra money was sent back to his extended family in Kastania, Greece.

“From when he was very young, there was a tremendous work ethic that he picked up from his family, and a tremendous empathy toward others,’’ said his son, David, of Phoenix. “Doing research that ultimately was worthwhile in helping other people’s lives was something that was very important to him.’’

Dr. Lagakos went to Carnegie-Mellon University in Pittsburgh, where he graduated in 1968 with a bachelor’s in mathematics. While studying there, he also met and married Regina Eckenrode, a student at Mount Mercy College.

From there he moved to George Washington University in Washington, D.C., where he graduated in 1972 with a master’s degree in public health and a doctorate in mathematical statistics.

Zelen hired Dr. Lagakos to work at the State University of New York at Buffalo, and a few years later, Harvard recruited Zelen. “I said the condition is that I have to bring 12 faculty with me,’’ Zelen recalled. “These were all young people, no one knew them too well, but I thought some of them were going to be great, and Steve was one of them. And Steve, of course, turned out to be better than all of us.’’

Joining the faculty at the Harvard School of Public Health in 1978, Dr. Lagakos rose to become director of the school’s Center for Biostatistics in AIDS Research. One focus of his work was designing studies to figure out how a woman infected with HIV transmits the virus to the fetus she carries and when that happens.

He chaired the biostatistics department from 1999 to 2006 and for more than 10 years was a statistical consultant to the New England Journal of Medicine. Among the many honors he received was the Spiegelman Gold Medal Award, presented in 1983 by the American Public Health Association.

“Steve educated several generations of biostatistics students, and his many postdoctoral fellows were devoted to him as a kind and compassionate teacher and mentor,’’ David Hunter, dean for academic affairs, wrote in an e-mail to colleagues at the School of Public Health.

“He was generous with young people, making them principal authors of papers for which he probably should have been the principal author, just to help their careers,’’ Zelen said.

One former student is De Gruttola, who succeeded Dr. Lagakos as chairman of the biostatistics department.

“It’s very hard to find people who excel at teaching and communication, at developing research projects that have an impact, and at the technical and mathematical aspects of statistics,’’ De Gruttola said. “He excelled at all of those, and that’s what’s increasingly hard to find. People tend to specialize in one of those domains, not cover the range of all three.’’

A large part of the legacy Dr. Lagakos leaves, colleagues said, is the lives he touched with work that took him from Boston’s suburbs to Africa and to Greece, where he traveled frequently in recent years.

“He had the utmost respect for those people who were trying to make a positive change in their community in the small sense, and in the wider sense of the Commonwealth of Massachusetts or the nation,’’ Rev. Young said of the time Dr. Lagakos spent with Woburn’s activists. “He came at the issue without bias or prejudice, but with an incredibly large heart and gave of his time. We could never have purchased his time if he charged us by the hour for his efforts. It was all donated.’’

In addition to his son, Dr. Lagakos leaves another son, Adrian of Wellesley; and two sisters, Patricia Huffman of Alameda, Calif., and Susan Cannon of Knoxville, Tenn.

A service will be announced.