A magazine long known for rating cars and washing machines is branching out to hospitals, encouraging people to shop around for ones that provide "conservative" instead of "aggressive" care.

Relying on data already compiled by researchers at Dartmouth College, the service launched by Consumer Reports on Thursday uses a simple, if counterintuitive, yardstick:

For older people struggling with chronic diseases, too much medical care can be dangerous, said Dr. John Santa, director of Consumer Reports’ new Health Ratings Center.

"Aggressive" hospitals keep people with chronic diseases hospitalized more days during the last two years of their lives. And doctors affiliated with aggressive hospitals see chronically ill patients more often.

"Conservative" hospitals provide the fewest doctor’s visits and shortest hospitalizations in those final years of life.

For older people with conditions such as congestive heart failure, cancer, dementia or diabetes with organ damage, the yardstick can be useful in deciding whether a hospital’s treatment style matches their needs.

The Health Ratings Center joins an expanding array of rankings, grades and evaluations that compare hospitals or doctors. Some are buried in government reports, while others are assembled by nonprofit groups, consumers or businesses.