That's partially BS generics are not always the same as brand name drugs. The manufacturing facilities are not the same the suppliers of active ingredients and the degree to which they are purified are not the same. So if insurance is covering brand name drug it's actually better it be prescribed vs generic.
The FDA standards for generics are 80% to 125% of AUC and Cmax (measures of bioavailability). So you could be getting up to 20% less or 25% more drug with a generic than the brand. Sometimes that matters, sometimes it doesn't.
A great example of a generic drug problem is with Wellbutrin, used for smoking cessation and as an anti-depressant. The FDA allowed Teva to market their 300 mg pill without actual bio-equivalence testing (they just extrapolated from the lower dose) and as a result a lot of patients had bad side-effects. Teva recalled the product.[1]
This company was fraudulently claiming that the drug profile of their generics was identical. Thanks to a whistle-blower the company was fined $500m by the FDA, after years of legal wranglings.
Obviously marketing works, and sales reps can help physicians by pushing research and information at the as part of their outreach -- just like any other relationship based salesperson.
The other equation missing is the impact of pharma sales practices with respect to the gatekeeper pharmacy managers. Who is taking the CVS/Caremark guy out for steak dinner and what is the rebate or consideration that the insurance company gets for choosing one drug over another.
In my case, my insurance company standardized on a drug in a broader class of medications that wasn't as effective for me -- I had some minor side effects and the metrics changed for the worse.
So my doctor switched me back to a non-preferred drug. His mousepad was provided by that drug maker. Is that an ethical issue?
increased by 0.1 percent for every $1,000 in industry money received
I'd love to know what the confidence interval is for this analysis. Prescribing varies wildly across physicians, so if a doc is receiving $10K in pharma money, is a 1% increase in prescribing relevant?
Combined with the stat you mentioned, it's a strange one. Maybe I'm looking at it wrong, but there's barely any physicians receiving above $50k in payments, so the biggest impact pharma payments have made is around a 5 % difference in prescribing. Looking at the variation at around $0-$10k, 5 % seems like a tiny change, since you have docs prescribing anywhere from 0 % and 80 %. Something else is driving it, my guess would be good personal relationships with sales reps? In that case, focusing on limiting that would have a much better impact on fixing the issue.
The big variation could also be something completely innocent like trust in a specific brand due to experience in the clinic, etc. Perhaps someone more knowledgeable can chime in.