Kim Erickson, 59, had to retire early from his job as an airline pilot after he learned that he had Parkinson’s disease. Since then, he’s participated in several clinical trials that he says could help find a cure.

But in that sense, he’s a rare case.

Less than 1 percent of people with Parkinson’s disease participate in clinical trials, and many end up dropping out before a trial’s completion. Without enough patients, researchers can’t complete the trials that are necessary to advance treatment options.

To find out why Parkinson’s patients might choose to stick with clinical trials until their completion — or more often, why not — University of Minnesota adjunct neurology professor Martha Nance got a $20,000 grant from the Parkinson’s Disease Foundation last month.

Nance is the medical director at Struthers Parkinson’s Center, the only National Parkinson’s Foundation-certified center of excellence in Minnesota. Members of the center provide clinical care, offer rehabilitation support and conduct research.

“I think this research will be really important as we and others design studies in the future to know what it is like from the patient perspective,” Nance said. “What’s keeping patients from wanting to participate in studies or wanting to stick with it once they’re in them?”

According to the Parkinson’s Disease Foundation, 90 percent of all clinical studies in the U.S. have to extend their original timelines to enroll enough participants.

Clinical trials are human research studies that aim to answer questions or find new treatments for diseases like Parkinson’s, Nance said. Patients can choose to participate and may choose to leave at any time perhaps because of the time commitment or testing inconveniences.

Improving treatments

Up to one million Americans and an estimated seven to 10 million people worldwide have the disease, according to the Parkinson’s Disease Foundation.

Although the disease varies by individual, the most common symptoms are tremors, slowness of movement, rigidity of different body parts and trouble with balance.

After Erickson retired, he said he had to start taking medication every day. Unlike many other patients, he’s had relatively few symptoms so far.

“It hasn’t affected a tremendous amount of my lifestyle, but unfortunately, in the future that might change,” Erickson said. “… I have a couple young granddaughters, and I would love to be part of finding a cure of a disease they may inherit.”

Because of the disease’s complexity and varying symptoms, Erickson said, current treatments can have unpleasant side effects and can’t be delivered in standard doses to each patient.

Patricia Ede, a research nurse clinician at Struthers who has helped facilitate clinical trials for nine years, proposed the idea to Nance of studying patient retention in clinical trials.

The researchers plan to send a one-page questionnaire to 70 patients who have been involved in clinical studies at Struthers over the past three years, to ask what they liked and disliked about the process.

“I can make the assumption that travel, appointment time of day and staff friendliness are important,” Ede said, “but I don’t know that until these patients send it back and tell us.”

Erickson, who is part of the foundation’s Parkinson’s Advocates in Research program, helped Ede and Nance formulate the patient-directed questions along with other patient advocates.

He said he hopes that a better understanding of why patients stay in clinical trials will lead to more participation.

While researchers of other diseases can just study blood samples, Parkinson’s researchers need to study the brain through clinical trials in order to better understand it and advance treatment, Nance said.

The Parkinson’s Disease Foundation has provided training to more than 230 Research Advocates in the past decade. In 2014, the foundation plans to award a total of $5 million toward Parkinson’s research programs.

The University Medical School, College of Pharmacy, School of Public Health and College of Science and Engineering together have received more than $11 million in grants to study Parkinson’s disease over the past five years, according to data from the Office of the Vice President for Research.

Nance said she hopes their research will help inform other researchers developing clinical trials in the future.

“We have a strong belief that there’s much more to doing well with Parkinson’s than just taking a bunch of pills,” she said.