We’ve all seen those best- places-to-retire lists. Inevitably, they are based on low taxes, good weather, or lots of activities. But how about this metric: Where will you get the best care if you are old and frail?

Hint: Oregon is good. Rural Louisiana is not.

The Dartmouth Institute for Health Policy and Clinical Practice, which has access to an enormous amount of Medicare data, has mapped the quality of local health care for older adults throughout the country and created a useful scorecard. Where are you most likely to be hospitalized, or be readmitted to the hospital, or get useless tests or dangerous drugs? Where will you spend those most time seeing doctors?  The study is based on 2012 Medicare data.

It turns out that there is enormous variation across the country in the way older adults get medical care, and some troubling patterns across these different measures. There are some parts of the country where older adults are likely to get good care. And there are others where it is likely to be downright dangerous.

Here are a few examples from the Dartmouth report:

Use of high-risk medications.  On average, 18.4 percent of Medicare patients get these drugs, many of which are anti-depressants. But in three regions of Louisiana—Alexandria, Monroe, or Baton Rouge—27 percent to 29 percent of older adults get these drugs, almost three times more  than in Sioux Falls, SD or Mason City, IA.

People with dementia getting a feeding tube: There is no evidence that feeding tubes prolong life or improve outcomes, yet they increase complications.  Overall, Dartmouth reports about 6 percent of decedents with dementia received a feeding tube in the last six months of life. But in Lake Charles, LA, the tubes were inserted in 14 percent of these patients while in Portland, Oregon, Salt Lake City, Utah, Madison, Wisconsin, they were used less than 2 percent of the time.

Hospitalizations:  On average, Medicare beneficiaries spent 4.6 days in in the hospital in 2012. But in Monroe, Alexandria, and Shreveport, LA they spent more than 7 days.  By contrast, seniors in Bend and Salem OR spent the fewest days in the hospital.

Preventable hospital readmissions: Nationally, these readmissions were cut from 5.5 percent in 2003 to 4.2 percent in 2012. But where you live says a lot about how likely it is you’ll be a regular visitor to your local hospital. In San Mateo and Santa Barbara CA, readmissions rates are about 2 percent, while in Monroe and Alexandria La, they hover around 7 percent.

Prostate cancer screening for men over 75:  A once-common blood test, known as a PSA test, is no longer recommended for older men. Yet, In Miami, nearly one-third of men 75 and older still get the test. In Casper, WY, it is administered to only 10 percent of older men.

Mammograms for women over 75: There is no evidence of benefit to older women and measurable risk of harm from false positives. Yet, in Sun City,AZ, 37 percent of older women still get this screening. In Miami only 15 percent do.

Time spent with doctors: On average, Medicare beneficiaries are in contact with the health system  17 days-a-year, either because they are hospitalized, seeing a doctor, or getting a test. But in parts of the New York City area, they spend nearly 25 days with the health system. Seniors in Marquette, MI and Lebanon, NH spend only 10 days-a-year seeing docs, getting tests, or being hospitalized.

Nobody is suggesting you move to Oregon just to get good health care. And even if you live in a community where overall care is poor, you still may get quality care from your own doctor. But the kind of studies that Dartmouth does are still very important. They show us that it is possible to improve care for seniors. Want to know how? Just ask the docs and hospitals that are already doing it.