After a report showing that doctors who accept gifts, food and money from pharmaceutical companies tend to prescribe those companies’ drugs more, ProPublica released another report with evidence those doctors tend to be located in the same areas.

Doctors in New Jersey tended to be more involved with pharmaceutical companies, with 80 percent taking some form of payment in 2014, compared to only 66 percent of doctors nationwide.

More than 76 percent of doctors at for-profit hospitals in several southern states accepted money from drug companies, including South Carolina, Mississippi and Florida. Doctors in Vermont and Minnesota took the least, at 19 and 30 percent, respectively.

“This analysis shows profound differences among hospitals, but it's uncertain why that is. It could be that hospitals play a role in shaping affiliated doctors' acceptance of payments or that like-minded physicians congregate at particular hospitals,” the report said.

Most hospitals have conflict-of-interest policies, but those can change and are not always clear to every party involved. Some organizations, such as the American Medical Student Association, advocate for more transparent relationships between hospitals, doctors and drug companies, so patients can get a better view of what could be influencing their treatment.

Check out NPR to see the whole joint report.