Some 58 percent of smartphone users have downloaded a health-related app, according to a NYU Langone Medical Center study of 1,604 US smartphone owners conducted in June 2015. Survey management company Toluna conducted the survey online.

A slightly smaller percentage of smartphone users, 41 percent, downloaded more than five apps. Almost half of respondents, 41 percent, said they would not pay for a health app, while 20 percent said they would pay a maximum of $1.99, and 22 percent would pay a maximum of between $2.00 and $5.99.

About 52 percent of users said they downloaded health apps to track physical activity, while 47 percent wanted to track what they ate. Forty-six percent said they downloaded health apps to lose weight and 34 percent said they wanted to use health apps to learn exercises.

A majority, 65 percent, of respondents that have downloaded at least one health app, opened it at least once a day, and 44 percent of this group used their app for between 1 and 10 minutes. While 35 percent of people with a health app found it by searching the app store, 30 percent learned about apps from friends and family, and just 18 percent found apps through web searches. Approximately 20 percent of respondents said that a doctor had recommended a health app to them.

Of the 41 percent who had not downloaded a health app, 27 percent they lacked interest, 23 percent cited the high cost, 15 percent said they did not trust the apps that were collecting their data, and 10 percent said they didn't need a health app.

The survey also identified a number of correlations in the data. According to the results, people who were more likely to use health apps were also often younger, had a higher income, received greater education, were latino, and had a BMI in the obese range. Researchers found that Latinos were 20 percent more likely to use a health app than white people, and people who earned more than $75,000 per year were 30 percent more likely to use a health app than those earning between $25,000 and $74,999. People who were obese were 11 percent more likely to use a health app than those in a normal weight range.