Introduction
What is new?
- 1.
There is a lack of agreement about the actual number of concomitant medications a person is taking that would be defined as polypharmacy.
- 2.
This study supports the widespread definition of polypharmacy that is linked to adverse outcomes as five or more medications.
- 3.
The number of concomitant medications was 6.5, 5.5, 4.5, and 4.5 medicines in association with frailty, disability, mortality, and falls, respectively.
- 4.
Our study provides evidence and clarification of the best cutoff value for the number of concomitant medications that should be used to identify older men at possible risk of different adverse outcomes.
Older adults display substantial variability in both beneficial and harmful responses to medications. With advanced age, there are age-associated changes in pharmacokinetics and pharmacodynamics, comorbidity, and patterns of medication use that may contribute to increased risk of adverse events [1], [2], [3]. Clinically, significant adverse outcomes of medication exposure in older adults include specific adverse drug reactions, falls, fractures, hospitalization, and physical and cognitive functional impairments [4], [5]. Polypharmacy, referred as the use of multiple medicines and/or the administration of more medicines than is clinically indicated, representing unnecessary medication use [6] has been associated with poorer clinical outcomes in observational studies of older adults [4], [7].
Although there is an evidence on the association of polypharmacy with adverse outcomes in older adults, there is a lack of agreement about the actual number of concomitant medications a person is taking that would be defined as “polypharmacy.” Some investigators have defined polypharmacy as the concomitant use of three or more medications [8] and others as the long-term simultaneous use of two or more medications [9]. Some studies did not explicitly state the minimum number of medicines used for the polypharmacy definition [10], [11]. In addition, further qualifiers have been explored to define types of polypharmacy including hyperpolypharmacy (use of 10 or more medications) [12], excessive polypharmacy (use of 10 or more medications) [13], [14], nonpolypharmacy (use of less than five medications) [15], and oligopharmacy (use of five or less medications) [16]. A recent study found that while the use of 10 or more concomitant medications was associated with poorer nutritional and functional status, and limitations in cognitive performance, the use of six to nine medications was only associated with poorer functional status in older people [15]. Identification and clarification of the best cutoff value for the number of concomitant medications that increase the risk of harm in older adults is important to guide prescribers and researchers considering polypharmacy in older people as a guide to improve medication-related outcomes. In addition, it may be that the thresholds in terms of number of concomitant medications above which risk increases depends on the adverse outcomes in question.
In the past, polypharmacy exposures were defined without specific clinical justification. To date, no study has been conducted to ascertain what number of medications should be considered excessively high on the basis of association with several different adverse outcomes. The aim of this study was to determine an optimal discriminating number of concomitant medications associated with geriatric syndromes, functional outcomes, and mortality in community-dwelling older men.