Primary care research conducted in networks: getting down to business.

This seventh annual practice-based research theme issue of the Journal of the American Board of Family Medicine highlights primary care research conducted in practice-based research networks (PBRNs). The issue includes discussion of (1) theoretical and methodological research, (2) health care research (studies addressing primary care processes), (3) clinical research (studies addressing the impact of primary care on patients), and (4) health systems research (studies of health system issues impacting primary care including the quality improvement process). We had a noticeable increase in submissions from PBRN collaborations, that is, studies that involved multiple networks. As PBRNs cooperate to recruit larger and more diverse patient samples, greater generalizability and applicability of findings lead to improved primary care processes.