One of the standard interventions in chronic disease management is prescription medication. Medications were historically employed chiefly as treatments to alleviate symptoms; however, in the late 20^th and early 21^st centuries, medications have been increasingly utilized as preventive agents to modify and/or reduce health risks.

Most chronic disease management and medication prescription occurs in primary care by family physicians. Although data are available for overall medication use for all age groups [3] and for specific medical conditions, [4-6] little is known about population-level prescribing patterns for family physicians providing care to older adults. Therefore, we asked the following research questions:

1. What are the trends of medication prescription to individuals aged 65+ in the province of Ontario by family physicians?

2. What are the most commonly prescribed classes of medication, and have they changed over a 10-year interval?

Table ​Table11 shows the relative ranking of prescription classes in both 1997 and 2006 and the percentage change in rank order according to percentage increase over the study period. In both 1997 and 2006, cardiovascular medications were the most commonly prescribed medications, followed by psychotropic and gastrointestinal medications. All medication classes increased over the 10-year period, with several of the medication classes increasing by more than 200%. The lowest increases were for primarily symptom-based therapies (non-steroidal anti-inflammatory medications, antibiotics, asthma/chronic obstructive pulmonary disease therapies, and corticosteroids.) The steepest increases were for primarily preventive therapies: medications to prevent osteoporosis increased 2,347%, and lipid-lowering agents used to prevent cardiovascular disease increased 697%. Preventive medications and medications for chronic disease management have increased as a relative percentage of claims, while more primarily symptom-based medications such as analgesics, antibiotics, NSAIDS, COPD medications, and gastrointestinal medications have declined.

Also presented in Table ​Table11 are the per person prescription claim rates for each of the unique classes of medication. (Compared to crude claims data, the use of 'claims per person' is advantageous as this measure controls for any change in the population of interest during the study period.) All classes of medication showed an increase in average annual claims per person. For example, for cardiovascular agents, in 1997 the average claims per person was 3.2544, whereas in 2006 the average claims per person was 9.4776, which represents an increase of 191%.

Figure ​Figure11 presents the distribution of the number of unique classes of medications prescribed to older adults in Ontario. Data is presented for the years 1997 and 2006. Over this 10-year period, the proportion of older adults making no prescription claims decreased by 36%, and the proportion of older adults taking one to three classes of medications decreased by 17%. Conversely, the proportion of older adults on four to nine classes of medication increased by 34%. Over the same time period, the proportion of older adults who were prescribed 10 or more classes of medication increased by 188%.

Figure ​Figure22 presents the number of prescription claims per person by gender. As illustrated, claims per person were higher among females than males. In 1997, the overall prescription claims rate for Ontarians aged 65+ was 10 claims per person (female = 11; male = 8); by 2006, the overall claims rate increased to 26 claims per person (female = 31; male = 20).

Figure ​Figure33 presents the number of prescription claims per person by age group for females and males, respectively. For the 10-year study period, there was an annual increase in the number of claims per person for both sexes. The rate of increase in the number of claims per person was greater for females than for males. This is true for all age groups: in the 65-74 age group, claims per person increased 107% for females and 101% for males; in the 75-84 age group, claims per person increased 170% for females and 132% for males; and, finally, in the 85+ age group, claims per person increased 286% for females and 210% for males.

The increase in prescription claims cannot be explained entirely by increase in population, as the prescription claims per person is almost threefold higher than population increases. The prescription increases may be partially explained by greater reliance on clinical practice guidelines, [8,9] particularly more aggressive identification and management of risk factors for chronic conditions such as cardiovascular disease and osteoporosis. This trend towards increased use of preventive medications has resulted in a greater number of medication classes per patient, which has resulted in a shift in the profile of the typical elderly primary care patient. Whereas the regimen for a typical elderly primary care patient consisted of fewer than five classes of medications, now a greater proportion of these patients are on more than five classes. Taken together, these findings raise important questions concerning quality of care, safety, and cost.

In terms of quality of care, it is difficult to discern the benefits associated with the steep increase in prescriptions, particularly the increase in the number of classes of medications prescribed and the steep increases in the oldest age groups (i.e., 85+). There is increased use of clinical guidelines to guide medication prescribing; however, there are few clinical trials that have included elderly patients and so all claims for the effectiveness of such therapies with elderly patients are extrapolations from trials of younger patients [10]. As well, the rising rates of prescribing speak to the increasing complexity of clinical care. Increasing medication rates might explain, at least in part, the observed increase in visits to their family physician [1]. Increased medication prescribing creates complex treatment regimens. For physicians, this added complexity results in the need for more intense monitoring and increased management of side effects. For patients and their families, following complex medication regimens is difficult and burdensome; therefore, adherence rates are often low [11,12]. Taken together, then, the complexity involved with complex medication regimens results in cases that cannot be properly managed in conventional primary care visits [13].

The dramatic increase in prescriptions also raises concerns for patient safety and the potential for iatrogenic harm, particularly as many older adults now take multiple concomitant medications [14-16]. A number of recent studies have raised potential concerns with increased use of medications such as antipsychotic medications in the older and vulnerable adults [17]. The interactions of many of these medications are unknown, but recent research has shown the possibility of many harmful interactions, especially in older adults who have physiologic changes that impact medication clearance and pharmaco-dynamics [18]. There is a risk that increasing medication use, even for appropriate indications, may initiate a "prescribing cascade" where a medication causes an adverse effect for which another medication then is prescribed, which then in turn can cause another adverse effect for which another medication is prescribed [19]. Therefore, it is imperative that future studies evaluate the harms and benefits of complex medication regimens.

The increases in prescription claims per person documented in this study provide the basis for further exploration of associated cost implications. With the baby boom generation about to enter retirement age, publicly-funded drug programs must assess their ability to bear the costs associated with dramatic increases in prescribing rates. A recent report published by the Canadian Institutes of Health Information (CIHI) noted that the top 10 medications prescribed for older adults in six Canadian provinces account for 48% of all medication expenditures on older adults [20]. It is important to note, however, that this report did not include data from Ontario, British Columbia, or Quebec as prescription claims from these provinces are not submitted to the National Prescription Drug Utilization Information System database that was used for this report. Similar increases in use of prescription medications in the past decade have been observed in England. In 1997, adults aged 60+ were prescribed 22.3 medications per year on average; by 2006, this had increased to 42.4 medications per year [21]. There is also evidence demonstrating that nearly half of the total expenditures on prescription medications are accounted for by 5% of the population; nearly half of these high-cost users were over the age of 65 [3].