Of note to me is that they are measuring improper use of prescribed opioids vs illegal dealings in opioids. The researchers themselves say they have no way of measuring the opioid black market. Should we really believe Chicago or Portland or Seattle have less of a drug problem than BFE Louisiana?
No doubt there are people in poorer areas with limited medical facilities that "need their scrips". But then plenty of people in Beverly Hills "need their anxiety/stress/life-coping prescriptions" (and pay cash for them) as well. Not to mention "party favors". I think either can be looked at as "hopeless, desperate people".
I can't really see any viable correlation in this research. Not to mention, why is JAMA making political statements, especially given lack of data? This is kind of like saying, "There is a correlation between over-prescribed opioids and places that have hurricanes." Also, they are creating a bias by only using Medicare data. They are practically targeting poor, rural populations.