Over the past two weeks, the scientific journals Nature and Nature Biotechnology published innovative studies about asthma, melanoma and Parkinson's disease. But all three had something more in common than their publisher: the iPhone.

More and more hospitals are using — and studying — the iPhone as an integral medical tool. Often through Apple's ResearchKit framework, which lets novice developers easily build apps for medical research, doctors and researchers are combining the study of technology with the study of disease.

In the the latest of these studies, published Monday in Nature Biotechnology, scientists at Mount Sinai Hospital's Icahn School of Medicine in New York tested the use of smartphones in medical research through a study of asthma patients.

The study used a mobile app, downloaded by 50,000 iPhone users, to survey people with asthma. Not everyone who downloaded the Asthma Health App — designed for the study through ResearchKit — actually had asthma and was eligible to participate, but about 7,500 of the 50,000 did enroll. About 2,300 completed multiple surveys about their asthma symptoms over a six-month period.

"The tech part of this is perhaps more important," said principal investigator Yvonne Chan, director of digital health and personalized medicine at a Mount Sinai institute. "The more important takeaway is that clinical research has been done the same way for centuries. It really is changing, revolutionizing how clinical research is being conducted."

"It really is changing, revolutionizing how clinical research is being conducted."

Researchers compared the results of the surveys to existing studies of asthma patients. The findings matched what they'd seen in other asthma studies, and even provided new information correlating asthma symptoms with external factors, like heat, pollen and a wildfire outbreak in Washington State.

"Research used to be a rigid, stodgy process," Chan said. "We are figuring out how to scale that and do it better in different ways."

With a mobile study, the researchers were able to reach a more diverse group of patients than in studies conducted the traditional way. For example, survey respondents were sicker than the group researchers can usually reach, Chan explained. They had higher rates of hospitalization and emergency department visits than Centers for Disease Control rates for asthma patients.

But the study pointed out that this method of research is still in its early stages and presents some drawbacks. Because participants self-report their own data, some values are often missing. And the study was prone to dropoff in participants over time, like any study requiring people to open an app of their own volition.

Apple's push into health care, too, has brought up concerns for some customers about privacy, in terms of both Apple Watch health data and data relating to more official medical information.

Still, as the iPhone gains more legitimacy in medical circles, Apple's relevance in the health care space grows. The tech company has kicked off its major push into health, collecting data from insurance-sponsored Apple Watches and apps developed through CareKit, ResearchKit's twin for consumer-facing health apps.

Past studies involving the iPhone and ResearchKit have focused on the scientific outcomes, like the correlation between stress and seizures found through Apple Watch data. In Mount Sinai's study, the conclusions about asthma itself were almost incidental. Instead, the real findings were how feasible mobile app-based studies could be for researchers in the future.

"Looking forward, the potential of ubiquitous smartphone technology to address the needs of clinical research to better understand health and disease appears to be more promising than ever," researchers wrote in the study.