For the past 55 years, the Rochester Epidemiology Project (though everyone calls it “The REP”) has been collecting and categorizing records—maybe 250 million medical and dental and psychological and educational records—from 1 million patients.

Including, probably, you.

Because the majority of those records—this “treasure trove of medical data” used for decades by researchers worldwide—have been gathered directly from Rochester residents since 1966.

A LOOK BACK: Rochester Epidemiology Project Timeline

It’s not just Mayo Clinic records. Olmsted Medical Center plays a major role. Olmsted County Public Health. Zumbro Valley Health Center. A longtime collaboration with Rochester Public Schools allows data point access—no personal info is ever shared without consent—to things like grades and visits to the school nurse.

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A number of area dentists have recently started to take part.

Only a few such studies in the world compare to The REP’s breadth (the city’s entire population, for the most part), depth (the data include things like school disciplinary records), and span (many individual records cover entire lifespans).

And, since its inception, researchers have taken notice.

The REP has been instrumental in determining that X-rays can cause leukemia, revealing that ovary removal increases risk of Parkinson’s disease, and creating effective treatments for postpartum depression.

Photo courtesy of the Mayo Historical Unit, Mayo Clinic, Rochester, Minnesota
Photo courtesy of the Mayo Historical Unit, Mayo Clinic, Rochester, Minnesota

An estimated 3,000 publications prominently cite REP-based research in arguably every field of medicine. Data from Rochesterites has contributed to key breakthroughs in everything from dementia to heart failure to multiple myeloma.

Osteoporosis, rheumatoid arthritis, stroke.

“The Rochester Epidemiology Project is a seriously important study,” says Dr. Walter Rocca, who has served as The REP’s co-director since 2006. “I don’t like exaggeration, but you don’t need to exaggerate to show the importance of this study.”

‘I’m living proof of its importance’

Here’s how important The REP is to Rocca: In 1993, when Mayo Clinic asked him to be part of the program, he left his native Italy for the chance.

“I’m living proof of its importance,” says Rocca, who comes from a farming family. “I left my country, my language, my food, my climate to be part of this. I don’t enjoy the winters in Minnesota. I like Rochester; I am happy here. The draw for me is the importance of this project.”

He has been working with The REP for 37 years. In 1984, while working for the National Institutes of Health in Maryland, Rocca, then a junior scientist, wanted to conduct a major study on epilepsy and seizures in children.

“I knew the Mayo Clinic was the only place in the world where this was possible,” says Rocca. “So I convinced my boss. We gave a contract to the Mayo Clinic, and I started coming over to Rochester to supervise my data collection.”

Dr. Walter Rocca in his office at the Biobusiness Center December 23, 2020. Rocca has done work on the Rochester Epidemiology Project. (Ken Klotzbach / kklotzbach@postbulletin.com)
Dr. Walter Rocca in his office at the Biobusiness Center December 23, 2020. Rocca has done work on the Rochester Epidemiology Project. (Ken Klotzbach / kklotzbach@postbulletin.com)

He made regular trips here for three years, on and off. By the late ‘80s, though, Rocca had returned to Florence, Italy to work. Then he got the call from Mayo Clinic asking him to join The REP.

He couldn’t say no.

He spent a dozen years as a researcher, tapping The REP for studies focusing on things like Parkinson’s and Alzheimer’s.

In 2006, Rocca was offered the formal leadership role alongside Olmsted Medical Center’s Dr. Barbara Yawn. Over the next decade, The REP was expanded to include a 27-county region in southeastern Minnesota and west central Wisconsin. And more than 1 million individuals.

Today, Rocca and current co-director Dr. Jennifer St. Sauver oversee the 380 or so projects—three dozen of which are funded by major federal grants—that are underway at any given time.

As for The REP itself, it has been funded continuously by grants from the National Institutes of Health since its official inception in 1966. The REP’s roughly $1 million budget is split by the NIH and Mayo Clinic. Right now, another $26 million worth of NIH grants are funding REP studies.

A piece of paper

The system—the idea itself—can be traced back to Henry Plummer, the Mayo Clinic doctor and “diversified genius” whose simple idea changed medical recordkeeping worldwide.

Prior to Plummer, individual physicians at the Clinic kept their own patient records—usually brief notes in chronological, diary form—in leather-bound ledgers.

In 1907, Henry Plummer, the Mayo Clinic doctor and “diversified genius”, changed medical recordkeeping worldwide. Doctors previously kept patient notes in leather-bound ledgers. Plummer’s new medical record consisted of loose pieces of paper collected in one single file for each patient so each physician could see all of the records pertaining to their patient. Photo courtesy of the Mayo Historical Unit, Mayo Clinic, Rochester, Minnesota
In 1907, Henry Plummer, the Mayo Clinic doctor and “diversified genius”, changed medical recordkeeping worldwide. Doctors previously kept patient notes in leather-bound ledgers. Plummer’s new medical record consisted of loose pieces of paper collected in one single file for each patient so each physician could see all of the records pertaining to their patient. Photo courtesy of the Mayo Historical Unit, Mayo Clinic, Rochester, Minnesota

In 1907, Plummer introduced a new system: Medical info would now be kept on loose pieces of paper and collected in one single file for each patient, who was then assigned a unique registration number. Now, each physician would see all of the records pertaining to their patient.

Plummer oversaw every aspect of the project, including testing various papers and ink—sometimes by leaving them on the roof of the office building—to make sure they would last through the years. It was an era of fountain pens. “All persons who write in the medical records are asked to use the ink supplied by the Clinic,” announced an in-Clinic newsletter, “in order to insure permanency of the records.”

The record-keeping system was officially unveiled on July 1, 1907. And Mayo had an international reach even then—the first patient to get a Mayo Clinic number hailed from Canada.

The new records paid immediate dividends. Patient 004, a 48-year-old woman, had complained to her doctor of pain and tenderness in her abdomen. When she returned to the Clinic two months later, her new physician matched up new symptoms with this note in her medical dossier, and successfully removed her gallbladder.

Plummer’s assistant, Mabel Root, continued to make upgrades to the system She added color coding, upgraded the numeric assignment, and introduced a dual indexing system.

Mabel Root (1878-1981), assistant to Dr. Plummer, added color coding, upgraded the numeric assignment, and introduced dual indexing to Plummer’s system. This early index card listed patients seen at Mayo Clinic for hypothyroidism. Photo courtesy of the Mayo Historical Unit, Mayo Clinic, Rochester, Minnesota
Mabel Root (1878-1981), assistant to Dr. Plummer, added color coding, upgraded the numeric assignment, and introduced dual indexing to Plummer’s system. This early index card listed patients seen at Mayo Clinic for hypothyroidism. Photo courtesy of the Mayo Historical Unit, Mayo Clinic, Rochester, Minnesota

Nine million patients later, the Plummer-Root system—the Unit Medical Record—is still in use. And not just at Mayo Clinic. This idea soon gained worldwide attention and is regularly cited as one of Mayo’s greatest contributions to medicine.

And so it went.

By the 1930s, Dr. Joseph Berkson created a system of classification codes to allow for medical sorting with the use of punch cards.

In the 1950s, Dr. Leonard Kurland, then a neurology fellow at Mayo, started to rely heavily on Mayo’s vast record-keeping system for his multiple sclerosis studies. He soon saw the significance in this raw data.

In 1966, Kurland asked the NIH for funding to link these medical records to multiple providers—schools, private practices, other hospitals—throughout Olmsted County.

He got it.

And he also got the cooperation—and records—from places like the Rochester Public School District and Olmsted Medical Center.

The Rochester Epidemiology Project was officially born.

In the 1930s, Dr. Joseph Berkson (1899-1982) created a system of classification codes to allow for medical sorting with the use of punch cards. Photo courtesy of the Mayo Historical Unit, Mayo Clinic, Rochester, Minnesota.
In the 1930s, Dr. Joseph Berkson (1899-1982) created a system of classification codes to allow for medical sorting with the use of punch cards. Photo courtesy of the Mayo Historical Unit, Mayo Clinic, Rochester, Minnesota.

A vaccine is called into question

In 1976, a life-threatening strain of virus struck the country.

A devastatingly deadly influenza, “swine flu,” seemed to be taking hold at the New Jersey Army post of Fort Dix—the same fort that was possibly ground zero for the 100-million-death Spanish Flu pandemic of 1918.

President Gerald Ford’s plan to vaccinate “every man, woman, and child in the United States” kicked off in March of ‘76, and, by the beginning of 1977, 45 million citizens—roughly a quarter of the U.S. population—had been vaccinated.

The swine flu, though, never took hold in the rest of the population as predicted. And then came the reports of a sharp increase of vaccine recipients with Guillain-Barré syndrome, a rare paralyzing disorder.

The nationwide vaccination program—described as “one of the largest and probably one of the most well-intentioned public health initiatives by the U.S. government”—was dubbed “a fiasco.”

Public sentiment seemed to turn against the programs. Against vaccines. Many people cited anecdotal information as anti-vaccine evidence.

It was research performed through The REP, according to Mayo Clinic, “that eventually disputed the original reports of stark vaccine-induced increases.”

Armed with the science and the statistics, researchers were able to present real numbers about the vaccine’s side effects, which were far less than critics claimed.

Those studies—that hard and fast science based on Rochester’s population—helped to legitimize vaccinations through a presentation of fact-based research.

‘Saying yes can change the world for someone else.’

Individual data is—and has always been—kept confidential in The REP.

But, up through the 1990s, no one was asking patients permission to share their raw data. They didn’t need to.

In 1997, though, Minnesota enacted a new state privacy law. Each patient would now be required to allow a review of their medical records, even for research.

The future of The REP—and those decades of records—was in doubt.

“If we did not find the solution, we would completely lose everything,” says Dr. Rocca. “Everything would be thrown away.”

The law, though, allowed an important caveat for info collected from previous patients: If due diligence was made to contact them, and they didn’t opt out, their records could stay in the system.

“Mayo spent a lot of money and a lot of effort to communicate with the people, educate the people,” says Rocca.

After all of the communication—tens of thousands of letters and numerous community announcements—less than 5 percent of Rochester residents opted out of The REP.

Robin Adams, a former administrative assistant to Dr. Rocca, also served as a member of The REP’s Community Advisory Board, which was created to make area residents more aware of their importance in these worldwide studies.

“I started out as part of the board when I worked at Mayo, but I wanted to stay on even after I left because I saw firsthand how important it is,” says Adams, whose four-year stint on the board ended a few months ago. “People can get a little scared when they get asked to share their medical records. But if you realize just what good comes out of it, you would be willing to say yes. Saying ‘yes’ can change the world for someone else.”

Robin Adams at her Stewartville home Wednesday, Dec. 23, 2020. (Joe Ahlquist / jahlquist@postbulletin.com)
Robin Adams at her Stewartville home Wednesday, Dec. 23, 2020. (Joe Ahlquist / jahlquist@postbulletin.com)

Fighting COVID-19

In mid-2019, 29-year Olmsted County employee Dan Jensen was named to a new position—Strategic Informatics Officer for Olmsted County.

He was working to tie together Olmsted’s information systems to interconnect all county departments to data that crosses health, housing, and human services.

Then COVID-19 hit. And Jensen was named COVID Operations Chief for Olmsted County.

Immediately, he relied on The REP.

“Right away, we were able to use [The REP] to help fight COVID in the middle of this craziness,” says Jensen, a John Marshall grad. “We were able to work with the state to find spikes in positivity rates for certain populations and deal with those immediately.”

Daniel Jensen, Olmsted County Health, Housing and Human Services Strategic Informatics Officer on mobility assignment as the COVID-19 Operations Chief, Monday, Dec. 21, 2020, in Rochester. (Joe Ahlquist / jahlquist@postbulletin.com)
Daniel Jensen, Olmsted County Health, Housing and Human Services Strategic Informatics Officer on mobility assignment as the COVID-19 Operations Chief, Monday, Dec. 21, 2020, in Rochester. (Joe Ahlquist / jahlquist@postbulletin.com)

Much of the early national info to help fight COVID—stats and studies about things like severity of COVID complications based on previous diabetes diagnoses—came directly from REP research.

That kind of information, says Jensen, is a microcosm of what makes The REP important, both worldwide and locally.

“To bring in that public health data on top of the medical data, that’s really very novel,” he says. “That does not happen in other places. And a big part of being part of [The REP] is that it honestly supports our ability to create a safe, thriving, and inclusive community. It affects the world. But it starts by helping Olmsted County.”

REP researchers can be anyone. Even you.

Here’s something: That world-class info is online.

Accessible to anyone.

Sure, the more in-depth studies, with access to more specific info, must be approved by Mayo Clinic and Olmsted Medical Center Institutional Review Boards.

But the basic info—the hundreds of millions of medical data points—is right there at www.rochesterproject.org/portal/.

Want to find out, say, whether migraine sufferers are more likely to have nutritional deficiencies? You can do that.

A simple pair of scroll-down menus lets you choose from hundreds of characteristics (Restless Legs Syndrome, Heart Valve Disorders, Obesity) and compare those diagnoses with other diagnoses (Gout, Immunity Disorders, Colon Cancer).

“If you go to the data exploration portal, there is no limitation. You can play freely,” says Rocca. “We have tried to make The REP as accessible as possible, to make the basic data available to a broader audience.”

It has changed the world. From our backyard.

While a few other countries—Denmark, Taiwan, parts of Canada—have effective systems to link medical records, Rocca points to The REP’s local collaboration as something that distinguishes it from other similar projects.

“We collaborate with the school system, and there are a number of projects where researchers were able to look at the school performance of kids as an outcome of something that happened medically,” says Rocca.

REP studies have led to new guidelines in administering anesthesia to children under 2. Reimagined treatment for head trauma in kids.

Rocca and his wife, Liliana, a child psychiatrist at Mayo, are currently studying children who have faced adverse childhood events (socially and emotionally) during childhood or adolescence.

“If you can imagine these kids living through these experiences and then growing up and trying to have a normal life, well it’s amazingly powerful to see how these early life experiences could change the way you live your life,” says Rocca. “We want to help others who have been through this. And to have access to the documents of these kids from teachers and doctors and psychiatrists is so powerful to be able to help in the future.”

And The REP, for example, changed the way the world viewed ADHD.

If you were born in Rochester between 1976 and 1982, you were probably part of that as well.

In the mid 1990s, Dr. Slavica Katusic and Dr. William Barbaresi tracked 5,718 Rochester school kids born between 1976 and 1982. They identified 379 cases of ADHD.

That study, which has continued to track many of these kids into adulthood, “helped change the myth that ADHD is just a minor childhood behavior problem that’s overblown and overtreated and overmedicated,” says Barbaresi, now the Chief of the Division of Developmental Medicine at Boston Children’s Hospital and a professor of pediatrics at Harvard Medical School.

“In the early 1990s, Dr. Katusic put together a proposal to do a study on learning disabilities and that was the study that brought us together,” says Barbaresi, who worked at Mayo from 1993 to 2009. “This was all her. I was just lucky enough to be a collaborator on such an important study.”

(While we did reach out a few times, Dr. Katusic, now retired, politely declined our interview requests.)

That study—the first large, population-based research to follow children with attention-deficit hyperactivity disorder into adulthood—discovered the kinds of facts and stats that shone a light on the need for early diagnoses and treatment.

The study—and numerous follow-ups—revealed that kids with ADHD were more likely to have reading disabilities, more likely to suffer from substance abuse, more likely to commit suicide.

“Our study has been an important contributor to the understanding that ADHD is a very significant chronic health problem,” says Barbaresi. “It often persists into adulthood. It has a huge potential to adversely impact the way major life outcomes turn out. And that’s why it’s worthy of our attention. It’s worthy of additional research to find ways to do better.”

And it was the willingness of those Rochester kids to actively take part in the study as adults that made it possible to help treat future kids with ADHD.

“When it came time to recruit the adults for interviews, there was genuine enthusiasm on the part of people, many of whom had suffered from the impact of their ADHD, and who understood this was an opportunity to maybe do something that could help other people who have the same problems,” says Barbaresi.

More than 60% of those adults, in fact, agreed to take part in the follow-ups.

“The research resources at Mayo, especially for these large scale studies that provide you information about large populations of people, are absolutely unparalleled,” says Barbaresi. “Those very, very bright people back in the relatively early 20th century recognized that if they developed a medical record in a way that information could be systematically retrievable to answer questions, that they would create this repository of information that could answer an unlimited number of questions. What an important part of medical history.”

For his part, Rocca is well aware of that history. He is, in fact, the lead author on the definitive “History of the Rochester Epidemiology Project: Half a Century of Medical Records Linkage in a U.S. Population.”

“We have a very important resource here, a resource that is much more complete than anywhere else in the world,” says Rocca, who is not prone to hyperbole. “And this resource is so complete because of these people right here in Rochester, people who understand it’s important to be part of this, to be part of something bigger."