In 1990, a small army of interviewers fanned out through the streets of Johnston County, NC. They went door-to-door, asking people age 45 and over if they’d be willing to be poked, prodded, X-rayed and asked a bevy of personal questions as part of an arthritis study. They also had to be willing to be followed by doctors for years and sometimes decades.

Impressively, 3,200 people signed up to help Dr. Joanne Jordan and a team of other researchers from the University of North Carolina in Chapel Hill and the Centers for Disease Control in Atlanta learn more about why and how people get arthritis. Dr. Jordan, a rheumatologist and epidemiologist who is now the director of the Thurston Arthritis Center at the University of North Carolina at Chapel Hill, conceived the Johnston County (JoCo) arthritis study as her graduate thesis project. Her research suggests that 1 in 2 people will develop knee OA before they are 85; the risk rises to 2 in 3 for people who are overweight or obese.

Population-based studies that follow people into the future are rare because they are labor intensive and expensive. It costs about $2 million a year to operate JoCo, which gets funding from both the Centers for Disease Control and Prevention in Atlanta, and the University of North Carolina in Chapel Hill.

Finding such a large group that will stick with such a study long-term can be a greater challenge than finding funding – and it’s essential to the validity of the study. 

Keeping in touch with arthritis study participants between their clinic visits is critical, because each person who drops out of the study weakens the results.  Dr. Jordan and her team have developed creative ways to keep residents of Johnston County motivated to participate.

“We’re not some ivory tower that comes down and swoops in. We have an office in the community, and we stay in touch with the people in our sample,” says Dr. Jordan.

“We try to make them feel like they’re really part of something,” she says. “This Christmas, for example, we’re having an open house where they can win door prizes, and some of our interviewers are really good cooks, so they make food.”

The osteoarthritis study participants also get paid a “token amount” of money for their time, but the real incentive for many is often the opportunity to receive free medical care.

“We do give people the results of their X-rays, the results of their cholesterol,” Dr. Jordan said. “They get a fair amount of medical testing they wouldn’t get otherwise. In some cases, we’ve been the first doctors to diagnose cancer or other serious diseases. We hate having to tell someone something like that, but we can also get them plugged into really good medical care. A lot of people really, really appreciate that because they would not have been able to do it otherwise,” she said.