Your recent article on a study of patient-centered medical homes in Pennsylvania was a balanced report about the success of this innovative, fast growing model of primary care ("Mixed messages from 'medical home' study," February 26).

We were not surprised that this study of medical home practices did not find an overall lessening in health care use or costs across all patients, many of whom are healthy, needing little or no care.

In contrast, we are pleased that studies we conducted of the medical home model showed very encouraging results. Our studies focused specifically on the health of the people for whom the medical home model was designed: high-risk patients and patients with chronic illnesses. Studying the treatment received by these less healthy patients from their primary care physicians, we saw a very positive picture: fewer hospitalizations, fewer emergency room visits, and better health outcomes—more patients with well-controlled diabetes and a 21 percent reduction in costs for diabetic patients.

Today nearly 41 percent of our primary care physicians practice using the medical home model — a huge advance since it was introduced here six years ago. We believe this model of care is a highly effective way for primary care physicians to concentrate on keeping their less healthy, chronically ill patients well.

Richard Snyder, chief medical officer, Independence Blue Cross, Philadelphia