The U.S. prices for the top-selling medicines are three times higher than in Britain, and 16 times higher than in the lowest-priced country, according to a Reuters analysis.

The review of prices looked at the 20 most popular prescription drugs, which account for 15 percent of the world’s spending on pharmaceuticals. The analysis also found U.S. prices were six times higher than in Brazil.

The United States, which lets pharmaceutical companies set prices, has higher prices than in countries where governments directly or indirectly control prices. Not surprisingly, the U.S. is easily the most profitable market for drug companies, according to Reuters. Critics say the result is that Americans are subsidizing health systems in other countries.

Drug companies say the prices are needed to offset research costs.