Hospitals aren't known for making house calls. Once patients get their discharge papers, they take their chances with a family doctor or staffers at a clinic who may or may not know what happened inside the hospital's walls. So Margaret Bennett's experience is pretty rare. Bennett, 84, who had a stroke 11 years ago and colon cancer in 2007, recently spent two weeks at Montefiore Medical Center in the Bronx because of a blood clot in her leg. In many places, such a frail and elderly patient might be hospitalized for weeks or even months, but Bennett's doctor now comes to her.