One of the main reasons why the United States’ health spending is so much higher than other countries is because the nation’s physician fees are so much higher, according to a study published in Health Affairs.

The study, “Higher Fees Paid To U.S. Physicians Drive Higher Spending For Physician Services Compared To Other Countries,” came to the conclusion that “higher fees, rather than factors such as higher practice costs, volume of services, or tuition expenses, were the main drivers of higher U.S. spending.”

The researchers compared payments for primary care visits and hip replacements in the United States, Australia, Canada, France, Germany and the United Kingdom. They also looked at expenses and medical education costs.

Public payers in the U.S. paid 27% higher fees and private payers paid 70% more for primary care visits compared to other countries. When it came to orthopedics, the difference was even more pronounced. In the U.S. patients paid 70% more for public and 120% more for private than their counterparts in other countries.

However, the study did show that despite doing the same work, physicians in the U.S. earned more than those in the other countries looked at. Primary care physicians earned $186,582, almost double what those in France make, and orthopedic surgeons made $442,450, which is more than $100,000 what runner-up physicians in the U.K. make.