Group Health studied how patients with treated hypertension used outpatient specialty care before, during, and after a primary-care redesign (the patient-centered medical home) was spread system-wide. David T. Liss, PhD, now a research assistant professor in medicine-general internal medicine and geriatrics at Northwestern University Feinberg School of Medicine, led the report in the Journal of General Internal Medicine.

"Redesigning care to a medical home seems to let primary-care teams do more, within their expertise, for their patients," Dr. Liss said. "Our results suggest this can avoid or prevent some specialty visits for patients with stable hypertension and a few co-occurring illnesses." He studied more than 36,000 patients with treated hypertension in Group Health's 26 medical centers.

Patients with hypertension and few other conditions had 27-28 percent fewer specialty visits in each of the three years after the medical home started being implemented, compared to beforehand, adjusting for potential confounders and including interaction effects. Those with some other illnesses had 9 percent fewer specialty visits during medical home implementation and 5 percent fewer specialty visits during the following year.

"In contrast, we found very different results for clinically complex patients burdened by multiple diseases in addition to hypertension," said Dr. Liss's coauthor Robert Reid, MD, PhD, a senior investigator at Group Health Research Institute, and an adjunct professor at the University of Washington (UW) School of Public Health and Community Medicine. For those patients, specialty use was 3 percent and 5 percent higher, respectively, during the first and second years after the medical home was implemented.

"This suggests a need for more effective co-management and better 'handoffs' of complex patients by primary care teams and specialists in the 'medical neighborhood' that surrounds the medical home," Dr. Reid said. "We think new approaches to coordinating care between primary care teams and specialists should give priority to complex patients."

A patient-centered medical home is an increasingly common way to amplify the effects of good primary care: It's like having a family doctor who knows the patients and leads a team of professionals making the most of current knowledge and technology - including e-mail and electronic health records - to deliver first-rate, coordinated primary care and reach out to help patients stay healthy. Dr. Reid has published evaluations of Group Health's medical home implementation, linking it to emergency room use.