Wearables boost eating disorder program completion, app engagement

Using wearable devices helps improve study completion among people with eating disorders, as well as boosts their engagement with a smartphone app intervention, according to a recent study. Greater program retention, in turn, may lead to better outcomes.

“By end of study, most individuals who met retention criteria in both groups reported substantial reductions in binge-eating episodes,” the researchers said, though wearable use does not seem to pose a significant advantage. “Our results support the utility and acceptability of a digital eating disorder intervention app delivered through wearable technology.”

Drawing from the Binge-Eating Genetics Initiative, a total of 170 participants (aged 18–45 years, 96 percent women) were enrolled in the study, all of whom had lived experiences of binge-eating disorder or bulimia nervosa. Participants were randomized to engage with a digital intervention app through an iPhone alone (n=84) or with adjunctive use of a first-generation Apple Watch (n=896).

The app, called Recovery Record (RR), involved a cognitive behavioural therapy-based program tailored for binge-type eating disorders. Users were instructed to log meals, moods, urges, and disordered behaviours. The intervention was delivered over 30 days, with baseline and endpoint surveys to assess retention, engagement, and illness severity.

Study retention, defined as completing the Eating Disorders Examination Questionnaire-V6.0 both at baseline and study end, was more common in the Watch group, though not significantly so (66.3 percent vs 59.5 percent; p=0.37). Meanwhile, study completion, which involves submitting saliva and microbiome samples at both time points, was significantly better among device users (54.6 percent vs 39.3 percent; p=0.045). [Int J Eat Disord 2022;doi:10.1002/eat.23726]

App engagement was likewise significantly better among device users. For instance, the Watch group opened the app more times in a day than iPhone-only comparators; this trend was true when including (mean, 13.6 vs 10.2; p=0.047) or excluding (mean, 3.5 vs 0.2; p<0.0001) meal logs. Device users also used the RR app significantly more times over 30 days.

Of note, the RR app led to significant improvements in binge-eating outcomes, with the overall mean number of episodes in the last 30 days dropping from 12.3 at baseline to 5.43 at study end (p<0.0001). Sixty-six percent and 59.7 percent of participants in the iPhone-only and Apple Watch groups, respectively, saw a reduction in the number of episodes after the 30-day intervention; the between-group difference was not statistically significant (p=0.20).

“No significant differences emerged between the Watch and iPhone groups in binge-eating episodes at endpoint and change in binge-eating episodes from baseline to endpoint, suggesting that both forms of the app may be suitable options for future users,” the researchers said.

Nevertheless, their findings revealed that “using wearable technology alongside a smartphone may promote overall engagement in apps like RR, which should be replicated with other digital ED interventions in future research.”