2.0 Polypharmacy in the Various Settings (Table 1)
There have been numerous studies that have documented the rates of polypharmacy defined
as multiple drugs in various settings. Fewer studies have focused on the use of unnecessary
drugs.
2.1 Ambulatory Care
Many studies in ambulatory care define polypharmacy as a medication count of five or more
medications. However, current medical practice guidelines often require multiple
medications to treat each chronic disease state for optimal clinical benefit. Therefore, an
elderly patient with at least two disease states, such as heart failure and chronic obstructive
pulmonary disease, will usually exceed this arbitrary threshold of > five medications . For
example, a 2005-2006 study from the USA reported by Qato et al used a population-based
survey of community dwelling persons 57-85 years of age . Overall 37.1% of men and
36% of women between 75 and 85 years of age took at least five prescription medications.
Table 1 shows the most common prescription medications reported. Moreover, among this
older age group taking at least one prescription medication, 47.3% reported the use of an
over-the-counter medication and 54.2% a dietary supplement. The use of unnecessary drugs
was studied in 128 older male outpatients from the United States . Overall 58.6% of
patients took one or more unnecessary prescribed drug. The most commonly prescribed
unnecessary drugs are summarized in Table 1.
2.3 Nursing Home Setting
Polypharmacy in nursing homes has been an ongoing concern over the past four decades. In
the late 1990's, the US Center of Medicare and Medicaid Services felt this to be such an
important issue that it implemented a quality indicator measure targeting patients on 9 or
more medications. A study using data from the 2004 United States Nursing Home Survey
found that 39.7% had polypharmacy defined by this quality indicator measure . Of note
the group with the lowest rate of polypharmacy was those patients age 85 years or older
(34.8%). Table 1 shows the top ten most common medication classes used among this
nursing home population. In contrast, a study of 64,395 Canadian nursing home patients
studied reported that only 15.5% were on > 9 medications . The top therapeutic drug
classes prescribed to this cohort can be seen in Table 1. To the best of our knowledge no
multisite study has been conducted examining unnecessary drug use in older nursing home
patients .