Catherine Offord in The Scientist:
For a few months in the first half of 2019, Chris Payze started each morning at home in Queensland, Australia, by jotting down answers to a series of questions. What time did I go to bed? How many times did I wake up? Speaking to The Scientist this April, 71-year-old Payze said she’d gotten “really into the groove” of this daily routine. “It only takes me about five minutes.” She recorded the information for a trial of melatonin, a hormone that regulates sleep-wake cycles and is often taken orally as a sleep aid, although it’s not clear how well it works. Payze has Parkinson’s disease, and for the last couple years, she, like many people with the condition, has been dealing with insomnia. “I just have awful trouble sleeping at night,” she explains. While she doesn’t feel sleep-deprived, the interrupted sleep “is just annoying me. I’d love to sleep through the night one night.”
Payze has participated in clinical trials for other medications, and volunteered for this one after reading about it in a local newsletter for people with Parkinson’s. But this trial was different from the others in one immediately obvious way: Payze would be the only participant. That’s because this particular 12-week study was what’s known as an N-of-1 trial. Focused on the collection of treatment-response data in a single patient, this relatively little-used trial design represents the ultimate form of patient-centered medicine. Researchers design a mini-investigation of a treatment’s effectiveness entirely around an individual, with the goal of determining whether or not a particular treatment works for her. The trial was organized in a randomized sequence of two-week periods. In each period, Payze took either melatonin or placebo, never knowing which she was taking. Having just finished the treatments, Payze will soon receive a report with her results, which she and her doctor can use to help decide whether or not she will include melatonin in her medications.