According to a new ProPublica analysis, doctors who get more money from drug and medical device makers prescribe more brand-name medications. The authors of the study have warned that the conclusion made by them after analyzing Medicare Part D prescription drug data, doesn’t suggest a direct relation between payments and doctors who chose to prescribe drugs from the particular companies making the payments.

However, they have found an apparent connection between average rates of total brand-name prescribing and getting industry money.

The practice improves the revenue of pharmaceutical companies. The trend could get stronger, when doctors receive additional industry money.

For example, in 2014, doctors who received over $5,000 had a 30.1% brand-name prescription rate, in comparison to the 19.8% rate for the internal medicine specialists who got nothing.

They found the correlation true in leading specialties like family medicine, ophthalmology, and cardiovascular disease.

Doctors can make money from medical device and pharmaceutical companies via numerous avenues for several reasons. For example, they can cover meal of physicians or their business travel costs, or give them money for becoming speakers at certified Continuing Medical Education events.

Now, the payments should be publicized under an Obamacare provision known as the Physician Payments Sunshine Act. They must be listed on Open Payments website of the federal government.

Doctors made a total of $6.5 billion from drug and device firms in 2014. Previously this week, the pharmacy benefits giant Express Scripts said that the average prices of branded drugs have become roughly twice since 2011, contributing to a huge rise in Medicare drug spending.

Obviously, it seems like doctors taking money from pharmaceutical companies would recommend more brand-name drugs, but there is no proof to prove the same.