The idea is because you have to pay a little bit out of your own pocket you are less likely to run to the doctors and get a prescription when nothing is wrong. Since it is your money that you could spend on something fun instead of a pill you will ask do you really need to buy the pill, or will a cheaper pill work just as well. Note that the above is the idea - there are various problems with it, but the idea makes some sense.
There is a real problem with some people going to the doctors and demanding a pill to fix some problem, doctors get tired of seeing this person and prescribe something relatively harmless just to get them to go away.
Doctors used to prescribe antibiotics for viral illness as well because people expected a pill from the doctor.
Some old people have no friends left so talking to the doctor is the only social life they have.
Do not confuse the above with with cases where there is something wrong and the doctor cannot figure out what.
The co-pays for some drugs can get pretty steep for people on fixed incomes like social security. If the only reason is to keep people from nagging the doctor, you'd think that the co-pays would be fixed instead of varying wildly depending on the drug.
There is a real problem with some people going to the doctors and demanding a pill to fix some problem, doctors get tired of seeing this person and prescribe something relatively harmless just to get them to go away.
Doctors used to prescribe antibiotics for viral illness as well because people expected a pill from the doctor.
Some old people have no friends left so talking to the doctor is the only social life they have.
Do not confuse the above with with cases where there is something wrong and the doctor cannot figure out what.