A plan to rate thousands of Minnesota doctors on quality and cost, due to be published today, has drawn objections from the Minnesota Medical Association even before its release. Medica, the state's No. 2 health plan, is scheduled to unveil the new ratings on its website as part of a growing movement to give consumers more information about quality of care. It's the first time Minnesota doctors will be rated by name, using a star system to show how they perform on a variety of national cost and quality measurements. Last week, Robert Meiches, MD, the MMA's CEO, asked Medica to delay the rollout, saying the rating system is prone to errors and unfair to physicians.