Table 1.

Categories and examples for the existing definitions of polypharmacy and associated terms (examples of the more recent definitions of polypharmacy have been underlined)

Numerical only definitions	Numerical definitions including a duration of therapy	Numerical definitions including a health care setting	Descriptive definitions
Five or more medications [27]	Two or more medications for over 240 days [23]	Five or more medications at hospital discharge [31]	Necessary polypharmacy: “Necessary polypharmacy regimens should be considered additional medications that can optimize functional status and prevent disability in older adults. For older patients receiving NP regimens, the benefits outweigh the risks” [8]
Six or more medications [32]	Over five medications for 90 or more days [33]	Five to nine medications during hospital stay [34]	Qualitative polypharmacy: “prescription of five or more medications including at least one drug considered potentially inappropriate for older adults” [15]
Ten or more medications [14]	Five to nine medications for 90 or more days [35]	Ten or more medications during hospital stay (also called excessive polypharmacy) [34, 36]	Psychotropic polypharmacy: “the concurrent use of two or more psychotropic agents in one individual” [16]
Seven or more medications [37]	Five or more medications in the same quarter of a year [38]	–	Appropriate polypharmacy: “optimization of medications for patients with complex and/or multiple conditions where medicine usage agrees with best evidence” [14, 39]
Five to nine medications [40]	Five or more medications in the same month [41]	–	“Use of medications which are not clinically indicated” [14, 42]