On the flip side, far more seniors who survived a heart attack were filling prescriptions for cholesterol-lowering statin drugs in Ogden, Utah, than in Abilene, Texas 91 percent compared to just 44 percent, the study found. That's even though statins are proven to reduce those patients' risk of another heart attack.
Even more surprising, the study found just 14 percent of seniors who've broken a bone because of osteoporosis were receiving proven medications to guard against another fracture ranging from 7 percent of those patients in Newark, N.J., to 28 percent in Honolulu.
"There's no good reason" for that variation, said lead researcher Dr. Jeffrey Munson, an assistant professor at the Dartmouth Institute for Health Policy and Clinical Practice.
Researchers with the Dartmouth Atlas have long shown that the type and amount of health care that people receive varies widely around the country, and that those who live where Medicare spends more don't get better quality care.
The newest report examined 2010 prescription data from the 37 million patients who get drug coverage under Medicare Part D, and found even more of a mixed picture when it comes to seniors' medications. For example, patients in the South were more likely to fill prescriptions for those riskier medications, but less likely than those in other regions to get the long-recommended treatments for heart and bone conditions.
The average Part D patient filled 49 monthlong prescriptions either new ones or refills in 2010.
But the study suggests doctors in some areas prescribe more readily. The highest number of prescriptions filled was in Miami 63 and the lowest in Grand Junction, Colo., 39.
Overall, patients in regions where Medicare Part D spent more on medications weren't more likely to receive the most effective medications, the study found.
Yes, seniors who are sicker will use more medications, but the general health of a region's Medicare population explains less than a third of the variation, the researchers concluded.
Patients don't always fill their prescriptions, because of cost or fear of side effects or myriad other reasons something this study couldn't measure. It also didn't examine differences in benefits between cheaper and more expensive Part D plans.
But if doctors were following guidelines on best medication practices, there would be far less variation around the country, Munson said.
Doctors "really need to ask themselves, 'Is there a good reason why my patients are getting less effective care than patients in the other regions,'" he said.
He urged patients to ask more questions, too: Why is this medicine being prescribed? What are the pros and cons? Is there something else I should consider taking?
The Dartmouth Atlas, funded by the Robert Wood Johnson Foundation, studies health trends using Medicare data; similar figures aren't readily available for the general population.