This isn't conclusive by itself. Thanks to the Internet, consumers can conduct their own research on what drugs exist to treat their conditions. Do patients in countries where prescription drug advertising is illegal ask fewer questions or have less understanding of or involvement in their healthcare?
You would be stunned at the number of people to whom it would never occur to search the web for drugs, and among those who do try to search, how poorly they do it. The average person is still not very intuitive when it comes to that area.
On top of this, the majority of drug consumers are old people, who (statistically speaking) are far less likely to even use the internet at all. This is why drug advertising can be quite useful for them.
