A new study has determined people with Alzheimer’s disease are less likely to participate in clinical trials without a spouse caregiver.

Alzheimer’s trials can struggle to get participants and require patients with a reliable study partner to enroll together. The findings revealed that additional recruitment and retention strategies may be required to increase enrollment of AD patients with non-spousal caregivers.

The results showed spouses accompanied two-thirds of Alzheimer’s clinical trial participants. That contrasts with the national average, which shows 68% of Alzheimer’s sufferers receive primary care from their children, children-in-law or grandchildren. The study found AD trial participants with a non-spouse or adult child were more likely to drop out before the study was completed and had a higher risk for a serious adverse event during the trial.

Demographics may be relevant to clinical trial designs. Only 5% of trial participants were Hispanic; they were also twice as likely to have an adult child study partner compared to a spouse. African-Americans made up 6% of participants and were three times as likely to have adult child study partners. The ratio of men and women with AD were similar, but most had female study partners/caregivers.

“This result is a call to action. Non-spousal caregivers and the patients they care for represent an untapped opportunity to increase recruitment into Alzheimer’s clinical trials and to assure that the research results reflect the broad community of patients and their caregivers,” said senior study author Jason Karlawish, M.D., co-director of the Penn Memory Center and professor of Medicine, Medical Ethics and Health Policy in the Perelman School of Medicine at the University of Pennsylvania.

The findings were published in the Wednesday edition of Neurology, the medical journal of the American Academy of Neurology. The research team included members from the University of Pennsylvania, UCLA and the University of California, San Diego.