1. Introduction
Chronic diseases such as diabetes, hypertension and heart disease are the leading cause of death worldwide and pose a significant challenge for healthcare providers to address in a comprehensive and coordinated manner [
1,
2,
3]. The World Health Organization projects that the deaths due to chronic diseases will increase from 38 million in 2012 to 52 million by 2030 [
2]. Moreover, approximately one in three Canadians live with at least one major chronic disease and this is expected to rise as a result of an aging population and other lifestyle risk factors [
1,
4]. Care for such patients is a growing focus in health services research and public health policy [
1].
Multimorbidity, the co-occurrence of two or more chronic diseases, adds another layer of complexity to the therapeutic management of chronic diseases [
5,
6]. Navickas et al. report that 95% of the primary care population aged 65 years and older are afflicted with multimorbidity [
7]. There is considerable strain on healthcare systems as multimorbidity is increasingly recognized as a cause of poor health outcomes, increased health service use, and associated costs [
5,
8,
9]. Age is a risk factor in developing chronic diseases and patients with multiple diseases are at a greater risk of adverse health outcomes, more frequent hospital admissions, longer hospital stays, regular medical specialist visits, and mortality [
6,
10,
11].
Patients with multimorbidity often require multiple drugs to achieve optimal clinical management [
12,
13]. The use of more medications than clinically indicated or the use of five or more prescribed drugs per day is referred to as polypharmacy [
14]. Globally, the elderly population takes an average of two to nine medications per day [
14]. Polypharmacy is an area of particular concern for medication management since the prevalence of inappropriate medication usage by the elderly is reported to vary between 11.5% and 62.5% [
15]. With increasing numbers of medications, the risk of adverse outcomes from drug–drug and drug–disease interactions simultaneously increases, leading to adverse drug reactions, medication non-adherence, reduced physical capacity, frequent hospital visits and mortality [
11,
16,
17]. These events are further exacerbated due to the metabolic changes and reduced drug clearance associated with aging [
18]. Polypharmacy is therefore known to be common among the older adult population who experience multimorbidity, and so identifying and reducing the number of medications a patient is receiving can lead to better outcomes and help improve quality of life [
11,
19].
Although healthcare services and guidelines are available for the management of multimorbidity, past research has found that these services are rarely adequately designed to meet the clinical challenges of treating multiple chronic diseases and are primarily developed based on trials of interventions for single diseases [
7,
9,
20]. Consequently, older patients often receive care that is complex, inefficient, ineffective and fragmented [
21]. There are several interventions that attempt to reduce potentially inappropriate medication usage to mitigate risks associated with multimorbidity, however, these require collaboration between various health care providers so that a complete picture of a patient’s medical condition is understood and addressed comprehensively by the healthcare team [
17,
18]. Spinewine et al. suggest that primary care must move towards a team-based care approach consisting of patients, the patient’s primary care provider and other health care professionals in order to improve clinical decision making, collaboration and communication, adherence, and monitoring [
20].
Pharmacists, in particular, are increasingly becoming integrated into interdisciplinary primary health care teams. In Canada, the province of Ontario has over 170 pharmacists integrated into primary care team settings including Family Health Teams (FHTs, or interdisciplinary group practices) and Community Health Centres (CHCs) [
22]. Within these teams, pharmacists engage in many direct patient care activities including medication management, identifying adverse medication usage, and patient education, notably through the delivery of medication reviews [
23,
24]. When working in a primary care team setting, pharmacists are typically paid a salary and as such are not remunerated on a fee-for-service basis for each medication review or other professional service activities [
25,
26]. Ontario pharmacists do not have broad prescribing authority although they are able to initiate therapy for smoking cessation. Pharmacists are able to renew or adapt a prescription if they have the original prescription order, unless it is for a controlled substance. They cannot order or interpret lab tests [
25,
26].
Pharmacist-led medication reviews in primary care have been shown to improve management of chronic disease and help to avoid adverse effects that result from polypharmacy [
3]. Medication reviews are also known to decrease the number of drug therapy problems and inappropriate medications by altering drug dosage, formulation and regimen [
24].
The objectives of this study are to understand the extent of polypharmacy, the processes and selected consequences of pharmacist-led medication reviews done in FHTs in the province of Ontario, Canada. The study aims to answer the following:
What are the characteristics of patients on ≥3 chronic or concurrent medications who received a medication review conducted by Ontario primary care team pharmacists?
What is the average number of medications per patient visiting a pharmacist in primary care?
What proportion of patients that have been prescribed ≥3 chronic or concurrent medications have been identified with (a) DTPs and (b) medications discrepancies by Ontario primary care team pharmacists?
4. Discussion
The occurrence of polypharmacy in aging populations is well known as older patients often require multiple medications to treat their chronic conditions [
35]. This study, which describes medication reviews conducted by pharmacists as part of interdisciplinary primary care teams, found that a large majority of patients cared for by the pharmacists were older adults classified as polypharmacy patients. Many of these patients were on medications that were difficult to manage or associated with high risk such as antidepressants, sedatives, opioids and insulin [
36]. The 2019 AGS Beers Criteria
® for PIM Use in Older Adults is a widely used, explicit list of medications that should often be avoided for older adults, which includes many of the types of medications that this sample of patients reported using as part of their daily medication regimens [
37]. These medications within the context of polypharmacy require a judicious balance of expected benefits and risks of adverse events when taken by older adults [
36,
37,
38]. The data from this study provide further support that primary care team pharmacists are well placed to identify opportunities that improve medication safety and effectiveness especially for community based older adults taking PIMs that may lead to an increased risk of adverse events [
35].
Despite many pharmacists classifying the patients as having a low complexity rating (i.e., the task is clear and well defined and all patient-related factors are present and easily interpreted), more than half of the patients had one or more medication discrepancies identified and majority of patients had at least one DTP. The complexity ratings may also have been categorized as low because the participating pharmacists were a very experienced group of pharmacists who were accustomed to dealing with complexity and as such could more easily handle cases that less experienced pharmacists may have rated as more complex.
In this study alone, 500 medication discrepancies were identified by pharmacists in the total patient sample and over half were drug name discrepancies. Research shows that medication-related errors and discrepancies account for approximately 44,000 to 98,000 fatalities per year and contribute to more deaths than breast cancer or HIV-related complications [
39]. Older patients, such as those in our study, are at especially high risk of such medication errors because of polypharmacy leading to complicated medication regimens and inadequacy within the current medication information sharing system, which can exacerbate the effects of polypharmacy [
40]. Studies indicate an exponential increase in the incidence of adverse drug reactions observed with initiating additional drug therapies to a patient’s regimen [
41,
42]. Our study supports that patients who have a high medication burden may experience an increased risk of medication errors, along with the increased risk of drug therapy problems such as drug–drug interactions, non-adherence, and increased overall drug expenditures among other things [
43,
44,
45]. Pharmacists can play an essential role in identifying these errors where the prescriber may have changed, added or omitted a medication for a patient.
Polypharmacy has also been associated with a higher risk of DTPs and the risk of hospitalization [
44]. A study conducted by Viktil et al., that compared patients taking five or more drugs with those that took less than five drugs, identified that the number of DTPs per patient increased linearly with the number of drugs used [
45]. A cross sectional study on DTPs identified during medication reviews deemed overtreatment as the most frequent DTP [
46]. This is consistent with a study conducted by Abdin et al., who detected an average of 7.2 DTPs per patient with the most common DTP as ‘drug use without indication’ [
23]. Primary care team pharmacists are in an advantageous position to have access to a patient’s longitudinal health record and regular interactions with the rest of the interprofessional health care team so as to identify care gaps, be it overtreatment or undertreatment, where medications may provide benefit for untreated health conditions. This study takes place in Ontario, Canada which has recently transitioned to a centralized health administrative structure led by Ontario Health, which will oversee a collection of Ontario Health Teams (OHTs) providing health care coverage across the province. Each OHT is expected to provide integrated care across health care sectors within a local community. As OHTs develop it will become increasingly important to have data available, such as the data from this study to inform decisions on allocation of health care provider resources [
47].
Pharmacists play a significant role in the reduction of polypharmacy through the provision of medication reviews. Thompson et al. determined that pharmacists usually prescribe fewer medications than physicians, which supports the movement of integrating pharmacists into primary care in attempts to reduce potentially harmful polypharmacy [
48]. Medication reviews ensure a patient’s medications are accurate and safe, engage patients in their own medication management, improve medication self-efficacy and adherence, and contribute to overall quality of life [
27,
28,
49,
50,
51]. Primary care pharmacists are optimally positioned to contribute to improving medication management and have been shown to reduce emergency room visits and hospitalizations as well as increase prescribing appropriateness, particularly for polypharmacy patients [
27,
52,
53].
Pharmacist-led medication reviews are essential to examine a patient’s medications and to assess what actions need to be taken to minimize and correct medication discrepancies and DTPs to maximize drug-related benefits [
39]. The identification and resolution of DTPs is one of the most significant contributions a primary care pharmacist can make. This study is consistent with other studies showing a high level of DTP identification among pharmacists based in primary team-based care settings [
54,
55]. Research has also shown that primary care team pharmacists have a higher rate of recommendations made and implemented as a result of medication reviews than those conducted by non-primary care team pharmacists [
56,
57]. Overall, pharmacists’ interventions have been shown to reduce incorrect or unsafe use of PIMs, DTPs, and medication discrepancies and is further supported by the research in Ontario, Canada where pharmacists, patients and health care professionals have reported improved quality of primary care [
58].
The strengths of this study include the diversity of the sites involved across the province and the multiple pharmacists that had participated. The pharmacists in our study practiced in a mix of urban and rural areas, although there was a greater concentration of pharmacists in urban areas who chose to participate. This is also the first report that combines data from of pharmacists participating in the Ontario Primary Care Team Pharmacists Network Limitations include the convenience sampling approach of pharmacists and data collection only taking place over a four-week period. This sampling approach only provides a cross-sectional perspective regarding polypharmacy among patients in primary care teams and therefore may not be generalizable to the general population. The retrospective nature of the data collection also limited the feasibility of obtaining follow up data for the majority of patients included in the study. Data may be skewed slightly towards a higher medication burden due to the inclusion criteria of patients with ≥3 chronic or concurrent medications.