Pharma companies say that money spent on promotion is essential to educate doctors about the best drugs - but when a medical student asked Joseph Ross, associate professor of medicine and public health at Yale, if those companies are promoting the right drugs for that message to be true, the answer wasn't available.

Ross and Tyler Greenaway, his medical student, then sat down and used the data from the US Physician Payments Sunshine Act to find out which drugs have the highest promotional budgets.

They cross referenced that against prescription databases and measures of value to assess the effectiveness, usefulness, and affordability of the drugs that get the heaviest promotion.

Read the full analysis: