Three established players -- HIMSS, the Continua Health Alliance and the HIMSS-owned mHealth Summit -- this year formed a group called the Personal Connected Health Alliance to facilitate consensus-building in digital health.

StartUp Health, for one, is working on its own platform to connect some of the early-stage companies it is incubating, and some of those companies are bullish on application programming interfaces. Basis Science, a StartUp Health alumnus that Intel purchased in March, is among those opening up data to outside developers, according to Stoakes. Fitbit is doing the same.

"If you're not making it easy for early-stage innovators to plug into your system, you will not be successful in the long term," Stokes says.

He also praises a few healthcare data initiatives from the federal government, such as Blue Button and HealthData.gov. "Some of their open-data platforms have been very valuable," he says.

Chaim Indig, founder and CEO of Phreesia, a vendor that makes patient check-in software and other apps to streamline the front offices of physician practices, is among those grateful for APIs that allow Phreesia's app/platform to sit on top of popular revenue-cycle management and practice management systems.

"It's the newer players that have been opening up," Indig says. Older practice management and EHR systems still are "walled gardens," according to Indig. "A lot of those walls are being forced to come down."

Phreesia recently completed two-way integration with athenahealth via a set of APIs. "Our product and their product don't live in silos," Indig says.

To him, Web APIs are superior to what he calls "non-scaleable" HL7 interfaces. "It allows discrete data into the system," not just file attachments, he says, and information can flow both ways. With these integrations, Indig says, "You don't have to worry about how your data gets into athena, back and forth."

The proliferation of APIs is one reason Stoakes is more optimistic than most of the physicians in the MedData survey. "Having a connectivity layer is such an awesome opportunity that someone is going to figure it out in the next 24 months because the market wants it," he says.

"We will figure this out faster than we believe," says Stoakes. "The opportunity is too great. We're not moving on a linear scale. It's an exponential growth curve that we're moving on."