INTRODUCTION
Polypharmacy is the use of multiple medications by a single patient
(most commonly defined as five or more concomitant regular
medications).1 Individuals over the age of 60 years
are commonly seen to be taking several medications. The main contributor
to this is multimorbidity, with most adults over 65 years having at
least two chronic conditions.2 From 2009-2016, 37% of
patients over 65 years of age attending US Physician offices were found
to be taking over 5 medications.3 Similarly high rates
of polypharmacy in have also been found in other
countries4,5 Within residential care, studies have
found that there may be as many as 91% of patients taking more than
five medications and up to 74% of patients taking in excess of nine
medicines.6
Polypharmacy itself has been clearly associated with a broad range of
negative clinical consequences.7 These consequences
include a decrease in compliance, increased risk of adverse drug events,
falls, impaired cognition, decrease in physical function, hospital
admission and increased frailty.8,9 The World Health
Organization has highlighted polypharmacy as one of the key areas to
prioritize in the mission to reduce medication harm.10
Depending on the individual, polypharmacy can be viewed as appropriate
(where the clinical benefits from medication outweigh the risk of harm)
or inappropriate. Achieving the desired balance between benefit and risk
in patients with multimorbidity can often be challenging, given that
evidence-based guidelines are usually for single health conditions. A
medication that poses a greater risk of harm than benefit (particularly
where there are safer or more effective alternatives) is termed a
potentially inappropriate medication (PIM). A significant positive
association has been described between the number of medications taken
by an individual and the likelihood of a PIM being
used.11 Multimorbidity, compounded by age-related
pharmacodynamic and pharmacokinetic changes all increase the use of PIMS
in the older population.12
Use of potentially inappropriate medications is commonplace. It is
estimated that one in five community dwelling individuals older than 65
years are prescribed at least one medication that is considered
inappropriate.13 It has also been estimated that over
a 5-year period, a quarter of all older Australians will be hospitalized
for an adverse drug reaction.14
Interventions to reduce polypharmacy and enhance the deprescription of
potentially inappropriate medications are the focus of current research.
The process of deprescribing can often be complicated and requires
individualization. While there are opportunities for intervention that
start from the time of prescribing, it is still unclear how best to
organize and implement processes to achieve a meaningful reduction in
inappropriate polypharmacy. There have been several systematic reviews
looking at the efficacy of deprescribing interventions within primary
care,15,16 within residential
care,17,18 and for
hospital-inpatients.19 However, another area that has
been less well researched is the impact of interventions delivered
within medical specialist outpatient clinics. Specialist clinics, such
as general medicine, geriatric, oncology, cardiology, and haematology
clinics, are likely to encounter patients with a high medication burden
and increased risk of medication-related problems due to advancing age
and multimorbidity. In patients reviewed at a heart failure clinic, 72%
were taking eleven or more medications.20 A recent
study, found that 41% of people who attended a memory clinic were
taking an inappropriate drug choice.21 Similarly, a
study of 248 geriatric oncology patients at an outpatient clinic found
PIM use in 51% of individuals.22 Although the patient
may not be referred to a specialist outpatient clinic for a
comprehensive assessment of all medications, there may be a possible
opportunity here to promote deprescribing. This review aims to examine
studies to date on the feasibility and effectiveness of deprescribing
interventions implemented within specialist outpatient clinics.