The newest batch of health IT companies to join the CommonWell Health Alliance has brought the interoperability group's total membership to 33 – quadruple the number as of this time last year.

"These newest members strengthen our representation in the ever-important oncology, telehealth and EMS as well as non-emergency medical transportation markets," wrote Nick Knowlton, vice president, business development of Brightree, who serves as chair of the CommonWell membership committee. They are:

ESO Solutions, which develops technology for connecting pre-hospital emergency medicine to the rest of the care continuum, including an EHR and an interoperability platform, signed on to CommonWell as a contributor member.

[Related: How does your EHR stack up? See our 2015 satisfaction survey results.]

Beyond Lucid, which develops software aimed at emergency medical services and medical transportation (an "EHR for ambulances") is now a general member. Its tools connect ambulances and non-emergency paratransit vehicles with hospitals prior to the patient's arrival.

MYidealDOCTOR offers a telehealth platform offering patients 24/7 direct links to physician consults and diagnosis. It is a general member of the CommonWell Health Alliance.

Varian Medical Systems manufactures medical devices and software for treating cancer and other medical conditions with radiation. Its informatics technology helps for manage comprehensive cancer clinics, radiotherapy centers and medical oncology practices. It is also a general member.