A crow flying from Vera Sinue's apartment in Boston's Roxbury neighborhood to her job as an insurance representative near the Charles River in Brighton would skirt the edge of the Longwood Medical Area, a district of medical institutions including Brigham and Women's Hospital, Beth Israel Deaconess Medical Center, Children's Hospital, the Dana-Farber Cancer Institute, and Harvard Medical School. These institutions are among the nation's most respected. They supplied some of the experts now leading the Obama administration's effort to reform the nation's health-care system.

Yet it's lucky for Sinue that when she began vomiting uncontrollably one day last August, she didn't end up at any of the Longwood hospitals. Sinue, who is 35, gets her routine medical care at the Codman Square Health Center, in the heart of the low-income neighborhood of Dorchester. Her Codman Square records would not have been accessible to any of the Longwood emergency departments. While Boston's medical institutions generally lead the nation in using advanced information technology for their own networks of physicians and satellite health centers (and the Longwood hospitals were early adopters), the networks don't connect with one another to share data about patients' medical histories and needs.