Prescription Drug Use Among Adults Aged 40-79 in the United States and Canada.

Patterns of prescription drug use may reflect underlying patterns of health conditions and health care access in the population. Polypharmacy, often defined as the simultaneous use of five or more prescription drugs, is more common in an aging population where multiple coexisting chronic conditions often occur; however, safety concerns may arise (1). The United States and Canada share many cultural and historical ties, but with different models for health care delivery (2). This report describes the use of one or more and five or more prescription drugs among adults aged 40-79 in the United States and Canada.