Drug prescription use has increased significantly in United States for the past decade.
The percentage of individuals taking at least one prescription drug in the past month increased from 44% in 1999-2000 to 48% in 2007-2008(Gu Q et al).
In 2009 prescription drugs accounted for 12% of total personal health care expenditures and reached $250 billion.
Prescription drug abuse is the fastest-growing drug problem presently in the US.
Medication related adverse outcomes increased 52% in hospitals and emergency departments between 2004 and 2008.
Drug prescribing patterns vary across geographic regions.
Drug prescribing patterns may serve as a proxy for health system performance.