The epidemiology of polypharmacy

Abstract

Polypharmacy describes, in simplistic terms, the use of multiple medications in an individual. It has become a normal aspect of modern medicine, driven by an ageing, multimorbid population, the increasing availability of preventative medications and an increasing use of single-disease guidelines and adherence to evidence-based practice. However, polypharmacy is also associated with a range of adverse outcomes, and is considered an important and increasing challenge for clinical practice. Here, we consider the definitions of polypharmacy, the extent and nature of medication use in different settings, and the type of problems encountered as a consequence of polypharmacy.

Keywords: Multimorbidity; pharmacoepidemiology; potentially inappropriate prescribing; ­polypharmacy.

Fig 1.

Percentages of adults prescribed medications in Scottish primary care in 2010 according to chapter in the British National Formulary. O&G = obstetrics and gynaecology. Data from Guthrie et al.

Fig 2.

Percentage of Scottish adults on given number of medications by age (A) and number of conditions (B). Adapted with permission from Payne et al.