21.   Reviewing the quality of mammogram images was left to a doctors trade group, the American College of Radiology.

22.   Since HMOs often pay doctor groups a set fee per enrollee, the groups try to have as big a roster of patients as possible.

23.   Solo practitioners and doctors groups have long been barred from sharing contract information on such matters as fees.

24.   Some employers tell employees which doctors groups and health plans have the best track records.

25.   Still, relations with doctor groups have been equally frosty.

26.   Such acquisitions are part of a health industry arms race that is leading to bigger hospitals, doctors groups, and HMOs, Sager said.

27.   The company, a provider of computer software for health-care providers, is expanding beyond small doctor groups and targeting large physician practices.

28.   The company owns two doctor groups, Medical Care Partners PC in Springfield, Mass. and Flagship Health in Maryland.

29.   The doctors group is also expected to play defense against separate bills that would extend prescription-writing power to psychologists, advanced-practice nurses and optometrists.