Not really, but there are some standards, like HL7[1]. But HL7 has some shortcomings. Lately there is an effort afoot to create a new standard called FHIR[2]. The problem is, even if the standard is finished and is GREAT, there's no way of knowing if the various vendors will actually implement it.
[1]: https://en.wikipedia.org/wiki/Health_Level_7
[2]: https://en.wikipedia.org/wiki/Fast_Healthcare_Interoperabili...