The American Medical Group Association, the organization representing some of the nation's largest physician practices, reported that it grew a bit larger itself in 2012, with the addition of 51 new groups representing some 13,600 physicians. That's a growth rate of nearly 12%, based on the number of physicians represented.

It is the 12th-straight year of growth, and the AMGA's membership now includes some 430 medical groups in which about 130,000 physicians practice and treat approximately 120 million patients, according to its 2012 Report to Members.

It's noted in the report that the average size of an AMGA member group is 302 full-time physicians and the median size is 140. The report added that the group has a 94% membership retention rate.

In comparison, in 2011, the AMGA added 45 member groups in which 8,500 practice. The AMGA passed the 400-member mark in 2011, but because of member organizations merging and consolidating, the number of members is not always a true indicator of the association's growth.

Activities listed in the 2012 report included the launch of Measure Up, Pressure Down, a three-year national campaign to combat high blood pressure through the use of members' coordinated-care delivery systems; and the conclusion of a two-year research project to improve care for patients with multiple chronic conditions. Launched in August 2010 and concluded in November 2012, the project included 22 teams and a report on their findings will be published in early 2013.

The report to members also said that the 2012 annual conference in San Diego set a record with more than 2,000 people in attendance. This year's event will be held March 14-16 in Orlando, Fla.