The community pharmacy is a critical source of medications, health services and health information to residents,[1, 2] and pharmacies are especially critical in socio-economically disadvantaged communities, where access to prescription medications via online pharmacies and to health information and resources is often impaired. The term “medication deserts” we introduce in this paper draws from the concept of food deserts, which is defined as low availability of nutritious food in underserved communities. Similarly, the presence of a medication desert is defined here as the low availability of the most commonly dispensed prescription medications in these areas. Little research has focused on the relationship between the SES of communities and geographic access to prescription medications at community pharmacies. The previous studies have raised concerns about the existence of systematic barriers in the timely procurement of prescription medications in disadvantaged communities. This concern is especially relevant because disadvantaged communities often have excess morbidity and mortality from chronic diseases, which require prescription medications for disease prevention and management[3–6].
The barriers to medication and pharmacy access can be differentiated into two principal groups: economic and geographic. Economic barriers may prevent individuals from procuring prescribed medication or adhering to the provider-prescribed medication regimen due to its high cost and/or lack of medication coverage.
On the other hand, the geographic location of the community of residence may affect individual’s economic or geographic access to medications. Residents that live in communities without a pharmacy or require lengthy travel to the closest pharmacy may face geographic barriers to accessing prescription medications regardless of their economic access. This is the case in rural areas of the United States (US) where the pharmacy is only accessible by car. These residents may also be at a disadvantage in accessing the range of health services and health information that the community pharmacies routinely provide.
Previous studies show that socio-economic factors, such as lack of health insurance and prescription coverage are associated with decreased access to medications, lower prescription medication use, and higher out-of-pocket spending[7, 8]. In the US, among 92 million adults with chronic conditions between 2002 and 2004, over 21% were uninsured for at least 1 month during the previous year. Rising medication costs worldwide are occurring alongside increases in medication utilization due to the surge in chronic diseases. Several studies aimed to examine the prescription medications dispensing patterns in Europe, United States and Canada and reported significant differences and reported increases in both cost and dispensing across countries and demonstrate that differences exist in access across areas of different socio-economic status[9, 10]. Higher prices and higher dispensing will likely mean greater medication expenditures for large groups of patients. For example, increased utilization of angiotensin-converting-enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and HMG-CoA reductase inhibitors (commonly referred to as statins) for cardiovascular disease (CVD) management will likely lead to increased costs to patients. Increasing costs associated with procurement of these critically-important medications may produce an economic barrier to access these medications by patients. Increased utilization of CVD medications may also increase their cost short-term, while non-adherence, procurement and their repercussions will also likely lead to overall higher costs to the system.
In addition to the economic access to the medications spatial access needs to be considered. Differences in land use, transportation networks, population density and distribution among different regions, such as rural vs urban areas also influence spatial access to the pharmacies and thus to the medications and health information provided by them. For example, one study showed that access to Human Immunodeficiency Virus-related retroviral medications, information and related health care services differed significantly for rural and urban residents.
Several contextual variables in communities of residence may affect access to medications. In many communities, residents must travel, sometimes for long distances, by private or public transportation to reach a pharmacy to procure medications. Therefore, access to transportation, e.g., a private car, may impact individuals’ ability to procure medications.
This study examines primarily the quality of health services provided by the neighborhood pharmacy (proxied by the availability of the most community prescribed medications) and geographic access to the closest pharmacy (proxied by mean density of pharmacies per neighborhood). From the theoretical perspective, several approaches have been pioneered to examine the mismatch between quality of health services and the need of the population across the SES strata and spatial mismatch between the need and geographic availability of various health services and information. The Inverse Care Law posits that the availability of health resources varies inversely with need. This approach exploits the notion that the market model produced stark variations in quality of health care that physicians are inversely related to the need of the populations served. “Inverse care law operates more completely where medical care is most exposed to market forces, and less so where such exposure is reduced”. Some community pharmacies may not stock commonly prescribed medications. For example, a recent study demonstrated the widespread failure of pharmacies located in the poor, predominately African-American communities to stock opioid analgesics.
Geographic perspectives on the issue of accessibility have mostly centered around the spatial mismatch hypotheses related to employment. In New York City, this approach linked residential higher segregation level to the reduced geographical accessibility to jobs for African-Americans and other minority inner-city residents. The mismatch approach to health services also related the existence of spatial disparities to the misbalance between health resources and disadvantaged population distributions. A recent study linked disparities in geographic access to first-line anti-malarial medications with the poverty level of the community surrounding the pharmacy. Such barriers in geographic access may impact medication procurement by the patients.
Even a brief review of salient literature on both topics reveals that that issues of equity loom large in the spatial distribution of health services[16–18] and contextual factors that influence health outcomes such as access to healthy foods[19–21]. Building on this earlier work, we consider the existence of pharmacy deserts. It is reasonable to assume that as with other health services, the reasons behind pharmacy siting decisions are rooted primarily in market forces and are not based on the need of the community. If we approach the problem from an equity perspective, the key question would be where is the best place to locate a pharmacy to maximize service to specific populations at highest need?
Several studies have examined the policies and economic forces thought to affect procurement of medications at the local pharmacies[7, 22–25]. However, several key concerns can be raised about this earlier research. Firstly, these studies focused almost exclusively on economic access and did not include geographic access in the analysis. Yet, geographic access has already been shown to be an important factor affecting access to medications and to other health services[22, 26–29]. Secondly, these studies were at the national level, and thus they did not examine the effects of socio-economic factors on geographic access at the community level. Yet, given these earlier findings about the key role the community socio-economic context plays in access to the health services, it is reasonable to hypothesize that the community’s socio-economic context may indeed have an effect on the quality and range of services that the local pharmacies provide. In particular, these local socio-economic forces may bear on the completeness of the medication inventory, and thus influence the residents’ ability to procure their prescription medications.
In addition to dispensing prescribed medications, the community pharmacies provide a range of important health information and services to the local residents[1, 2]. In many areas, pharmacists also administer immunizations and deliver preventative services. For example, in the US pharmacists routinely administer influenza and pneumococcal vaccinations and some pharmacies participate in the Expanded Syringe Access Program (ESAP) providing non-prescription syringes to help prevent transmission of HIV and of other blood-borne diseases[1, 30]. These activities highlight the importance of the community pharmacy as a key source of medications, health services and information. Because of this role, pharmacies are uniquely positioned to improve health outcomes in underserved communities and access to them is especially critical in disadvantaged communities, where access to other health resources is poor.
A number of national-level studies have examined access to medication[7, 22–25]. These studies, however, focused almost exclusively on economic barriers and did not examine geographic barriers in the analysis, an important factor affecting access to medications[22, 26–29]. These studies were also at the national level, and thus they did not examine the effects of socio-economic factors on geographic barriers at the community level. Earlier findings, however, suggest that a community’s socio-economic context plays a key role in access to medications. If such community differences in both types of access do indeed exist, they would suggest inequality in access to medications and to the range of other health services provided at the community pharmacy in different areas and thus should be carefully examined.
Economic conditions in the community and the geographic access to medications by the local residents may be related through a number of pathways. In particular, it is plausible to assume that the local economic conditions in the neighborhood may influence the prevalent type of pharmacies located there (small independent stores vs chain outlets), density of pharmacies and which medications are in kept in stock. The need to develop a survey methodology to examine relationships of the local socio-economic conditions on geographic access to the common prescription medications by the residents and to analyze them served as the impetus for the current study to characterize medication access at the community level.