Vertical Integration		The degree of integration and coordination of activities across operating units of an IHDN with complementary clinical and operational missions (e.g., affiliated general practitioner group, surgery center, and rehabilitation center).
VHA		Voluntary Hospitals of America, one of the larger GPOs. Also, Veterans Hospital Administration, a large system of hospitals throughout the US, operated by the Federal government for the benefit of military veterans and their families.
Visit		See patient case.
VSI		Very seriously ill. See SI.