Fallon Clinic in Worcester, MA is in discussions with the state’s largest private medical practice to form an affiliation that the organizations say would improve patient care and control costs. Fallon Clinic's discussions are with Newton-based Atrius Health, an affiliation of Dedham Medical Associates, Granite Medical, Harvard Vanguard Medical Associates, Southboro Medical Group and South Shore Medical Center. Those groups, in total, have 844 physicians and about 717,000 patients, with Harvard Vanguard the largest. "Fallon Clinic and Atrius Health are in significant discussions about how we can improve patient care together through an affiliation and hope to reach a conclusion shortly," the organizations said in a joint statement. Jack Dutza, MD, president/CEO of Fallon Clinic, declined to comment and referred questions to a spokeswoman hired by the organizations.