Users of the online fitness site were more likely to adopt new functionality -- in this case, a calorie-and-exercise tracker that offered a real-time look at a user's weight -- if fellow users of the same gender or similar age and body mass index were also using it.
Policy implications of these findings, says Centola, who is helping the site PatientsLikeMe analyze data on its 130,000 users, who connect with people with similar medical conditions, include providing incentives for social interactions, conducting sentiment analysis of the information that's shared to revise future messages and repeatedly messaging the people you want to join.
The last point stems from another experiment Centola conducted. In a closed, invitation-only network, users were more likely to come back the more "signals" they received indicating that others were joining the service; the "eager beavers" who joined early on, it turns out, were least likely to keep using the service.
3. Usability: Give users something familiar
Getting people to use health and wellness services isn't always about gathering data every 60 seconds and providing real-time feedback on what it all means. What patients often want, notes Dr. C. Anthony Jones, chief marketing officer for Philips Healthcare's patient care and clinical informatics business group, is a seemingly "mundane" application that, for example, lets them make a doctor's appointment on their smartphone.
The challenge, of course, is making sure it's not mundane -- booking an appointment, Jones says, should be no more difficult than making a dinner reservation using OpenTable. Demographics are a key factor here. As Jones sees it, the wellness movement essentially began in the mid-1990s, when baby boomers turned 50 and marketers, seeing an opportunity, appealed to boomers' interests like never before. As a result, wellness apps typically target a demographic less tech savvy than the people making them.
For wellness application developers, considerations extend beyond ease of use. Even typeface matters. In studying driving's impact on seniors, Lisa D'Ambrosio, a research scientist in the MIT AgeLab, discovered that "humanist" fonts, with rounded letters and numbers that look handwritten, are easier for older drivers to read than fonts with squared edges.
4. Home care: Make it easy, involve everyone
Driving is immensely important for seniors; if they can't get around, they become isolated. It's part of a larger wish to remain independent and avoid entering institutionalized care. This isn't surprising, D'Ambrosio says, noting that today's seniors are wealthier, healthier, better-educated, and more diverse than ever before.