Context: An investigation by ProPublica found that at least 21 doctors have been paid more than $500,000 for speeches and consulting by drugs manufacturers since 2009, with half of the top earners working in psychiatry, and about $2 billion in total paid to doctors for such services. AstraZeneca, Johnson & Johnson and Eli Lilly have paid billions of dollars in federal settlements over allegations that they paid doctors to promote drugs for unapproved uses. Some prominent medical schools have since tightened rules on faculty acceptance of such payments by drug companies.

Question: Who conduced an investigation on doctors?
Answer: ProPublica

Question: Billions of dollars have been paid by which companies?
Answer: AstraZeneca, Johnson & Johnson and Eli Lilly

Question: How much was discovered to have been paid to doctors by drug companies?
Answer: more than $500,000

Question: What was the reason these companies have to pay fines?
Answer: allegations that they paid doctors to promote drugs for unapproved uses

Question: How many doctors have been paid by varies companies?
Answer: at least 21

Question: A ProPublica study found that some doctors were being paid how much money for speeches?
Answer: more than $500,000

Question: Half of the top earners were mostly in what field?
Answer: psychiatry

Question: Drug manufacturers paid off doctors a total of how much money?
Answer: $2 billion

Question: Who conducted an investigation on drugs?
Answer: Unanswerable

Question: Billions of drugs have been paid why which companies?
Answer: Unanswerable

Question: How much was discovered to have been paid to drug companies by doctors?
Answer: Unanswerable

Question: What was the reason these doctors have to pay fines?
Answer: Unanswerable

Question: How many companies have been paid by various doctors?
Answer: Unanswerable