A new lexicon for polypharmacy: Implications for research, practice, and education.

Previous research suggests that polypharmacy is a significant challenge for health care systems. However, polypharmacy has been defined in at least 24 distinct ways, which has understandably caused confusion among researchers, educators, and students in health care. Previous definitions of polypharmacy capture what could be both inappropriate therapy, i.e. too many medications, as well as evidence-based therapy that is appropriate. Previous research has tried to focus on the number of medications a patient is prescribed to define polypharmacy; however only focusing on the number of medications a patient is taking may be of limited value in determining whether that patient will experience an adverse event. This paper proposes a lexicon change for polypharmacy. It suggests that in future research, polypharmacy be defined as patients going to more than one pharmacy for their prescriptions. The authors also proffer a new term, 'extraordinary prescribing,' to define patients who are taking medications that are either grossly excessive or not beneficial for that patient. This definition is different than the current use of polypharmacy because the number of medications a patient is taking is irrelevant, especially if that patient has multiple chronic diseases. This paper is meant to start a dialog within the health services research community to inform future research that examines why inefficient prescribing may harm patients and the broader health care system.