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: ఒక ప్రోపబ్లికా అధ్యయనం ప్రకారం కొంతమంది డాక్టర్లకు ప్రసంగాలకు ఎంత డబ్బు చెల్లించబడుతోంది?
answers: more than $500,000