Greater new YORK hospital association (gnyha) is a trade association that advocates for its member hospitals, health systems, and continuing care facilities. Gnyha's advocacy helps its members deliver high-quality, cost-effective care. For more information, see SCH o.greater new YORK hospital association (gnyha) is a trade association comprising nearly 280 member hospitals, health systems, and continuing care facilities in the metropolitan new YORK AREA, throughout new YORK state, and in new jersey, connecticut, and rhode island. Gnyha uses its policy expertise and vast analytical tools to advocate for our members. From fighting for their interests in washington and albany to working with them to improve patient care to helping them prepare for and respond to emergencies, gnyha works to ensure that our members have the tools to succeed.