- Email: [email protected]
Multiple pharmacy use and types of pharmacies used to obtain prescriptions
RESEARCH
Multiple pharmacy use and types of pharmacies used to obtain prescriptions Kevin A. Look and David A. Mott Received February 20, 2013, and in revised form May 5, 2013. Accepted for publication June 11, 2013.
Abstract Objectives: To evaluate trends and patterns in the prevalence of multiple pharmacy use (MPU) and to describe the number and types of pharmacies used by multiple pharmacy users from 2003 to 2009. Design: Retrospective, cross-sectional, descriptive study. Setting: United States from 2003 to 2009. Participants: 89,941 responses to the Medical Expenditure Panel Survey over 7 years. Intervention: Analysis of respondent pharmacy use behaviors. Main outcome measures: Annual use of more than one pharmacy and number and types of pharmacies used. Results: MPU among patients using medications increased significantly during the study period (from 36.4% [95% CI 35.2–37.6] in 2003 to 43.2% [41.9–44.4] in 2009)—a relative increase of 18.7% (P = 0.01). Multiple pharmacy users used between 2 and 17 different pharmacies per year to obtain prescription medications. Although approximately 70% of multiple pharmacy users used only two pharmacies, the proportion using three or more pharmacies increased from 24.1% (22.5–25.7) in 2003 to 29.1% (27.4–30.8) in 2009. Mail service pharmacy use had the largest relative increase among multiple pharmacy users during the study period (27.2%), and MPU was nearly twice as high (75%) among mail service users compared with non– mail service users.
Kevin A. Look, PharmD, MS, is a PhD candidate and American Foundation for Pharmaceutical Education Fellow; and David A. Mott, PhD, is Hammel/Sanders Distinguished Professor and Division Chair, School of Pharmacy, University of Wisconsin–Madison. Correspondence: Kevin A. Look, PharmD, MS, School of Pharmacy, University of Wisconsin, 777 Highland Ave., Madison, WI 53705-2222. Fax: 608-262-5262. E-mail: [email protected] Disclosure: Dr. Look is supported by an American Foundation for Pharmaceutical Education Predoctoral Fellowship. The authors declare no conflicts of interest or financial interests in any product or service mentioned in this article, including grants, employment, gifts, stock holdings, or honoraria. Previous presentation: American Pharmacists Association Annual Meeting & Exposition, New Orleans, LA, March 9–12, 2012; and Midwest Social and Administrative Pharmacy Conference, Madison, WI, August 8–10, 2012. Published online ahead of print at www. japha.org on October 4, 2013.
Conclusion: MPU is common on a national level and has increased greatly in recent years. Patient use of pharmacies that have the potential to share medication information electronically is low among multiple pharmacy users, suggesting increased workload for pharmacists and potential medication safety concerns. This has important implications for pharmacists, as it potentially impedes their ability to maintain accurate medication profiles for patients. Keywords: Multiple pharmacy use, pharmacy types, pharmacy patronage. J Am Pharm Assoc. 2013;53:601–610. doi: 10.1331/JAPhA.2013.13040
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T
he U.S. health care system has long been characterized as a fragmented system that delivers poor-quality, high-cost care lacking coordination among different providers that a patient might see.1,2 The use of multiple physicians has long been a concern, as Medicare beneficiaries see a median of two primary care physicians and five specialists working in four different practices in a single year.3 This fragmentation leads to frustrating and dangerous patient experiences, waste and duplication, and medical errors, hindering providers’ ability to deliver high-quality, efficient patient care.1 Multiple pharmacy use (MPU) is an analogous and important safety and quality issue for pharmacists and patients. MPU occurs when an individual obtains prescription drugs from more than one pharmacy location and stems from a patient’s experience and satisfaction with different pharmacies.4 MPU can result in fragmented patient care because pharmacists may not have access to the medications dispensed at other pharmacies. This decreases pharmacists’ ability to monitor for drug interactions and provide appropriate patient consultation.4–7 MPU has been linked to many undesirable outcomes affecting patient safety or quality of care, including inappropriate drug use and adverse drug reactions,7–9 de-
At a Glance Synopsis: An analysis of data from the Medical Expenditure Panel Survey showed that multiple pharmacy use (MPU) increased from 36.4% in 2003 to 43.2% in 2009—a relative increase of 18.7%. Although approximately 70% of multiple pharmacy users used only two pharmacies per year, the proportion using three or more pharmacies increased by 20.7% from 2003 to 2009. Approximately 75% of patients who used mail service pharmacy were multiple pharmacy users. Analysis: Of concern for pharmacists is the trend showing that MPU is becoming increasingly common on a national level, with more than two in five individuals reporting the use of more than one pharmacy in 2009. In addition, the use of three or more pharmacies increased. The increasing trend in MPU could be a result of increased use of mail service pharmacies by insurers and employers, as respondents who used a mail service pharmacy were about twice as likely to use multiple pharmacies compared with respondents who did not use mail service pharmacy. These results suggest that a majority of patients using multiple pharmacies are using pharmacies where medication profiles are not linked electronically. This lack of coordination among different pharmacy providers can result in increased workload for pharmacists, as well as important safety and quality concerns.
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creased patient adherence,10,11 increased mortality,6 and an increase in ambulatory care and hospital expenditures.5,6,12 The prevalence of MPU and the number of pharmacies used likely is associated with several changing trends in the U.S. health care system. Access to employer-based prescription drug insurance has reduced the impact of price as a barrier to medication use and may be associated with higher rates of MPU.13 Mail service pharmacy increasingly is being used as a cost-saving measure for insurers and employers.14 In 2012, 93% of employers offered access to a mail service pharmacy for maintenance medications and 23% of employers had mandatory mail service plans (5% increase from 2011).15 In addition, pharmacy location and convenience to a patient’s home, work, or medical providers are consistently rated as one of the most important reasons for selecting a pharmacy,16–22 which could result in increased MPU when patients select the most convenient pharmacy to obtain a medication rather than patronizing one pharmacy provider. The fact that certain pharmacy types (e.g., community chain pharmacies) use linked computer systems that enable medication profiles to be shared electronically across stores also may promote MPU. A final contributing factor is the use of incentives by pharmacies to encourage patients to transfer prescriptions among pharmacy corporations.23 The number and type of pharmacies used by multiple pharmacy users have important implications for pharmacists. When patients use multiple pharmacies having a centralized computing system that allows pharmacists at different sites to share patient medication profiles electronically (e.g., pharmacies from the same community chain, group of independent pharmacies), it is easier for pharmacists to link fragmented medication profiles that exist across multiple pharmacies. However, when patients use multiple types of pharmacies that are not linked electronically, and thus do not share patient medication profile information electronically (e.g., multiple independent or community pharmacies, multiple health systems, mail service pharmacies in combination with community pharmacies), patients may be at highest risk of harmful effects resulting from pharmacists’ inability to review and maintain a complete and current medication profile.4–7 When this occurs, pharmacists must spend additional time coordinating with the patients’ other pharmacies to link fragmented medication profiles, likely adding to pharmacist workload and stress. Prospective drug use review (PDUR) systems may provide a limited safety net for patients with drug insurance that use multiple pharmacy types that are not electronically linked. Although PDUR systems communicate potential drug–drug interactions and other drug use warnings to dispensing pharmacists via a centralized claims processing system, the interaction checks often are incomplete and do not account for prescriptions that are obtained outside the insurance plan (e.g., cash prescriptions, $4 Journal of the American Pharmacists Association
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generics).24 In addition, such a system does not exist for individuals without drug insurance. Little is known on a national level about trends in the prevalence of MPU or the number and types of pharmacies used by patients who visit multiple pharmacies. A total of 14 studies were identified that included any estimate of the prevalence of MPU (Table 1), with even fewer describing the types of pharmacies used. In addition, only four studies have included information on the total number of pharmacies used by the study sample. MPU estimates among noninstitutionalized adults have ranged from 7.0% to 44.6% (mean 26%) and have varied considerably depending on patient population, sample size, geographic location of participants, time period, and methods and instruments used for data collection.16,25–28 An additional limitation is that few recent studies have estimated the prevalence of MPU. To date, only two studies that included MPU estimates were performed using national data. A telephone survey of households located throughout the continental United States found that patients rarely used more than one (72%) or two (24%) pharmacies on a regular basis in 1996.21 The second study, a nationally representative survey of Medicare beneficiaries, found that 35.7% used more than one pharmacy in 2003.13 To the authors’ knowledge, no studies have been performed using large datasets representative of the general U.S. population, have shown trends in the prevalence of MPU over time, or have provided information about the number and type
of pharmacies patronized by multiple pharmacy users. Information about MPU is useful because of the potential burden that MPU places on pharmacists. Because little is known about MPU, identifying how commonly it occurs is important to determining the scope of the issue. In addition, evaluating information on the types of pharmacies used by multiple pharmacy users can help to inform strategies to limit the effects of MPU on pharmacist quality of care and patient safety.
Objectives This study sought to evaluate trends and patterns in the prevalence of MPU and to describe the number and types of pharmacies used by multiple pharmacy users to obtain prescription drugs from 2003 to 2009. Multiple years of respondent data obtained from a nationally representative survey of health care use, expenditures, sources of payment, and health insurance were analyzed. Data were obtained using consistent measures over time, in order to provide more reliable estimates of MPU than previously reported.
Methods This study used data from the Medical Expenditure Panel Survey (MEPS). Conducted annually by the Agency for Healthcare Research & Quality since 1996, MEPS provides nationally representative estimates of health care use, expenditures, sources of payment, and health insurance coverage for the U.S. civilian noninstitutional-
Table 1. Summary of studies estimating the prevalence of multiple pharmacy use Study Kabat8 Raffoul et al.32 Laverty19 Ostrom et al.28 Shepherd and Crawford McCombs et al.5 Ranelli and Coward33 Monane et al.10
25
Metge et al.21 Stergachis et al.17 Xu4 Safran et al.13 Polinski et al.34 Cocohoba et al.11
Study population Adult pedestrians in Minnesota Random sample of registered voters age ≥60 years in Fayette County, KY Consumer families demographically balanced to be representative of the U.S. population Low-income older and disabled individuals (≥60 years) living in two federally supported Seattle high rises Systematic random sample of older (≥60 years) Texas residents 5% sample of California Medicaid recipients who used cimetidine Random sample of older adults (≥60 years) in Florida Older (≥60 years) New Jersey Medicaid enrollees newly started on antihypertensive drug Random sample of households in the continental U.S. Random sample of households in the continental U.S. that filled at least one prescription in the previous 6 months Older individuals (≥60 years) in West Texas 1% national probability sample of noninstitutionalized Medicare beneficiaries (≥60 years) Older individuals (≥60 years) enrolled in the PACE program in Pennsylvania Cohort of women with HIV or at risk for HIV receiving pharmacist counseling
Sample size (n) 1,400 67
Using multiple pharmacies (%) 44.6 20.9
~1,500a
22.0
183 509 2,862 400
25.0b 37.9 18.5 14.3
8,643 984
21.0 28.0
1,201 2,545
26.0 23.3
17,685 182,116 783
35.7 21.7 24.0
Abbreviations used: HIV, human immunodeficiency virus; PACE, Pharmaceutical Assistance Contract for the Elderly. a Exact sample size not given. a Although 93% of the residents patronized a single pharmacy for prescription service, one-fourth had used more than one pharmacy in the previous year. Journal of the American Pharmacists Association
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ized population.29 MEPS collects information about each household member as reported by a single household respondent and uses an overlapping panel design, collecting data for respondents via five rounds of interviews during a 2.5-year period. We used the Household Component of the MEPS, which includes detailed information on health care use and expenditures, health status, health insurance coverage, and demographics. We also used the Prescribed Medicines (PM) file, which includes information on every acquisition of a prescribed medication reported by household respondents during the calendar year. The PM file contains detailed information on the medication acquired, including associated medical conditions (if any), sources of payment, and types of pharmacies from which medications were obtained. The sample included community-dwelling adults from 2003 through 2009. We excluded children younger than 18 years because parents or caregivers likely dictated their pharmacy selection. We restricted our sample to respondents who had two or more medications dispensed (i.e., opportunity to use multiple pharmacies). A medication dispensation was defined as each acquisition of a new prescription or a refill of an existing prescription. The study sample consisted of seven cross-sectional samples in consecutive years, ranging from 12,938 in 2003 to 13,612 in 2009. When nationally representative survey weights were applied, the weighted population size ranged from 129,366,234 individuals in 2003 to 137,590,486 individuals in 2009.
Study variables MPU, the number of pharmacies used, and types of pharmacies used by MEPS respondents were determined using the variables that described the type of pharmacy respondents used to obtain medications. MEPS respondents were asked to report the name and location of each pharmacy from which they obtained prescription medications. Each unique pharmacy location used by the respondent is included in the PM file as a separate variable (numbered sequentially from 1 to n), such that each different location of a pharmacy organization is treated as a separate pharmacy (M.N. Stagnitti, personal e-mail communication, April 2010). That is, a person who obtained medications from three separate locations within the same community pharmacy chain would have three separate variables in the dataset. These “type of pharmacy” variables (PHARTP1 to PHARTPn) represented all of the pharmacy providers from whom a patient’s medications were obtained during the survey year. Because every pharmacy location is entered as a separate variable, we defined the number of PHARTP variables with nonmissing values as the total number of pharmacies used by that respondent. We classified MPU as occurring when a respondent used more than one pharmacy location. The additional information about each pharmacy reported in the PHARTP variables was obtained in response to the question, “What type of pharmacy is that? Is it a mail-order pharmacy; a pharmacy located in another store such as a grocery or department store; a pharmacy located in an HMO [health maintenance or-
Prevalence of multiple pharmacy use
44% 43% 42% 41% 40% 39% 38% 37% 36% 35% 2003
2004
2005
2006
2007
2008
2009
Year
Figure 1. National prevalence of multiple pharmacy use: 2003–09 Estimates weighted to represent the national adult noninstitutionalized population.
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ganization], clinic, or hospital; a drug store that is not located within another facility; or is it an on-line pharmacy?” Because information about the type of pharmacy was obtained via self-report and no definitions were provided by MEPS personnel, the PHARTP variables reflected MEPS respondents’ perceptions of the types of pharmacies used. Of important note, two respondents may report different pharmacy types for the same pharmacy location. Although respondents were asked to report the pharmacy name and location, the pharmacy names documented by MEPS interviewers are not released to the public. As such, grouping the pharmacies used by a respondent by type, corporate owner, or health system was not possible. This precluded examining whether a patient used pharmacies that are able to link medication profiles electronically across different pharmacy locations. Thus, we report the types of pharmacies used by respondents using the predetermined categories described above and contained in the MEPS PM file. Statistical analyses The ICE command30 in Stata 11 (Stata, College Station, TX) was used to impute missing data that remained after data cleaning and editing by MEPS personnel. The ICE procedure uses the switching regression method, which incorporates nonmissing data into a series of linear or logistic regressions for each observation to generate plausible values for the missing data. Less than 4% of all observations had missing values, with no variable having more than 2% of values missing. All demographic and health characteristics variables were included to maximize available information for the imputation and to minimize bias. The imputed data were used for all analyses, and yearly MEPS person-level weight variables were used to account for the complex sampling strategy and to make nationally representative estimates for the civilian noninstitutionalized U.S. population for each year. We calculated descriptive statistics for each sample for each study year. Variables included age, gender, race and Hispanic ethnicity, education, poverty status, employment status, health insurance, drug insurance, perceived health status, and number of medical conditions. T tests and chi-squared tests were used to test for differences in demographics and health characteristics between the 2003 and 2009 samples. MPU rates and the number of pharmacies used were calculated with 95% CIs from 2003 to 2009, and linear regression was used to test for statistically significant linear trends in MPU. An alpha of P < 0.05 was used to determine statistical significance. The frequency of using each type of pharmacy across the study years was determined. This study was granted exemption status by the University of Wisconsin Health Sciences Institutional Review Board.
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Results The demographic and health characteristics of the sample population remained stable between 2003 and 2009, with the exception of insurance coverage and employment status (Table 2). Consistent with an economic recession, employment status and the proportion of respondents who reported having private health insurance decreased, with corresponding increases in the rates of public health insurance and being uninsured. However, the proportion of respondents with prescription drug insurance increased every year, rising from 79.8% in 2003 (95% CI 78.8–80.7) to 89.3% in 2009 (88.6– 90.0). Across the study years, individuals who used multiple pharmacies were more likely to be 65 years or older, be female, be white, be unemployed, have drug insurance, have lower perceived health status, and have a higher number of medical conditions. Figure 1 shows the weighted annual prevalence of MPU among noninstitutionalized adults in the United States from 2003 to 2009. A statistically significant increase in MPU occurred during the study period (from 36.4% in 2003 [35.2–37.6] to 43.2% in 2009 [41.9–44.4]; P < 0.001). The prevalence increased sharply in 2008 and 2009 despite no systematic changes in the way variables related to MPU were collected or measured. The prevalence of MPU increased by 6.8% (5.0–8.4; P < 0.001) during the study period—a relative increase of 18.7%. Multiple pharmacy users reported patronizing between 2 and 17 different pharmacies per year, with approximately 70% using only two pharmacies per year (Table 3). The proportion of multiple pharmacy users who reported using three or more pharmacies increased significantly from 24.1% (95% CI 22.5–25.7) in 2003 to 29.1% (27.4–30.8) in 2009 (P < 0.001). The prevalence of using three or more pharmacies increased significantly (by 5% [2.7–7.3]; P < 0.001) during the study period, which represents a 20.7% relative increase. Table 4 shows the types of pharmacies used by respondents who reported using multiple pharmacies. The top panel shows that between 2003 and 2009, an increase occurred in the proportion of multiple pharmacy users using community pharmacies (i.e., chain and independent), pharmacies located in another store (i.e., pharmacies located in mass merchandiser stores, grocery stores, or department stores), and mail service pharmacies. When these data are combined with similar data for single pharmacy users (data not shown) across the study years, approximately 75% of mail service pharmacy users and nearly 90% of online pharmacy users were multiple pharmacy users. The second panel of Table 4 shows the use of pharmacies among multiple pharmacy users who reported using only two pharmacies that were of the same type. Overall, across the study years, approximately onehalf of individuals who reported using two pharmacies used pharmacies of the same type, with the proportion j apha.org
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24.8 (23.5–26.0) 60.1 (59.3–60.8) 76.5 (75.1–78.0) 9.8 (8.8–10.8) 8.4 (7.6–9.3) 5.2 (4.5–5.9) 6.5 (6.0–7.0) 11.7 (11.0–12.4) 32.3 (31.2–33.4) 49.5 (48.2–50.9) 10.5 (9.7–11.2) 4.1 (3.6–4.5) 13.1 (12.2–13.9) 29.9 (28.7–31.2) 42.4 (40.8–44.0) 60.9 (59.7–62.1) 75.1 (73.9–76.3) 18.4 (17.4–19.4) 6.5 (5.9–7.0) 80.9 (80.0–81.8) 18.1 (17.1–19.0) 31.2 (30.1–32.2) 31.7 (30.6–32.7) 13.5 (12.8–14.3) 5.6 (5.1–6.1) 1.2 (1.2–1.3)
76.9 (75.6–78.3) 10.1 (9.2–11.0) 8.1 (7.2–8.9) 4.9 (4.2–5.5)
7.1 (6.5–7.8) 12.5 (11.7–13.4) 32.2 (31.1–33.3) 48.1 (46.6–49.6)
10.6 (9.8–11.3) 4.2 (3.7–4.7) 13.2 (12.4–14.0) 29.3 (28.1–30.5) 42.7 (41.1–44.3) 61.1 (59.8–62.4)
75.5 (74.3–76.7) 18.0 (17.0–19.0) 6.5 (5.8–7.1) 79.8 (78.8–80.7)
18.2 (17.2–19.3) 31.9 (30.8–33.0) 31.2 (30.1–32.2) 13.3 (12.5–14.2) 5.3 (4.8–5.8) 1.2 (1.2–1.3)
28.6 (27.5–29.7) 46.6 (45.4–47.8)
2004 % (95% CI) 12,961 130,242,252
24.5 (23.1–25.9) 60.2 (59.4–61.0)
29.1 (27.9–30.3) 46.4 (45.1–47.8)
2003 % (95% CI) 12,938 129,366,234
18.5 (17.4–19.6) 31.9 (30.7–33.0) 31.0 (30.0–32.0) 13.3 (12.5–14.1) 5.3 (4.8–5.8) 1.3 (1.2–1.3)
74.6 (73.4–75.8) 18.2 (17.2–19.3) 7.2 (6.6–7.7) 84.6 (83.8–85.3)
10.4 (9.7–11.1) 4.0 (3.5–4.5) 12.9 (12.0–13.7) 29.8 (28.6–31.0) 42.9 (41.3–44.6) 60.8 (59.5–62.1)
6.1 (5.6–6.7) 11.9 (11.1–12.6) 31.7 (30.6–32.9) 50.3 (48.7–51.8)
75.9 (74.4–77.4) 10.0 (9.0–11.0) 8.8 (7.8–9.7) 5.3 (4.6–6.0)
24.4 (23.3–25.6) 59.8 (59.0–60.6)
28.4 (27.3–29.6) 47.1 (45.9–48.4)
2005 % (95% CI) 12,925 133,290,595
17.8 (16.8–18.7) 32.4 (31.3–33.6) 31.8 (30.7–32.9) 12.9 (12.2–13.6) 5.1 (4.7–5.6) 1.3 (1.2–1.3)
74.1 (73.0–75.3) 18.7 (17.6–19.8) 7.2 (6.7–7.7) 86.5 (85.8–87.3)
10.4 (9.6–11.1) 4.6 (4.2–5.1) 11.9 (11.1–12.7) 29.3 (28.2–30.4) 43.8 (42.3–45.3) 61.5 (60.2–62.8)
6.3 (5.7–6.8) 11.4 (10.7–12.1) 30.8 (29.6–32.0) 51.5 (50.0–53.1)
75.5 (73.9–77.2) 10.2 (9.1–11.2) 9.1 (8.2–10.0) 5.2 (4.4–5.9)
24.9 (23.8–26.0) 59.3 (58.4–60.2)
28.2 (27.0–29.5) 46.9 (45.7–48.0)
2006 % (95% CI) 13,263 133,224,180
18.5 (17.4–19.5) 31.3 (30.2–32.4) 32.1 (31.0–33.2) 13.4 (12.7–14.1) 4.7 (4.3–5.1) 1.4 (1.3–1.4)
72.7 (71.5–73.9) 20.1 (19.1–21.1) 7.3 (6.7–7.9) 86.6 (85.9–87.4)
10.7 (9.9–11.4) 4.1 (3.7–4.6) 12.2 (11.4–13.0) 29.0 (27.8–30.2) 44.0 (42.5–45.5) 61.5 (60.3–62.7)
6.0 (5.5–6.5) 11.2 (10.6–11.9) 30.5 (29.3–31.8) 52.2 (50.8–53.7)
74.9 (73.5–76.4) 10.4 (9.4–11.4) 9.3 (8.4–10.2) 5.4 (4.7–6.1)
24.9 (23.8–26.0) 58.9 (58.1–59.7)
27.6 (26.4–28.8) 47.5 (46.3–48.7)
2007 % (95% CI) 12,007 133,800,147
Abbreviation used: FPL, federal poverty level. Estimates weighted to represent the national adult noninstitutionalized population. a P < 0.01, 2003 vs. 2009. b P < 0.005, 2003 vs. 2009. c Medical conditions included high blood pressure, coronary heart disease, angina, myocardial infarction, other unspecified heart disease, stroke, emphysema, diabetes, arthritis, and asthma.
≥65 Womenb Race/ethnicity White, non-Hispanic Black, non-Hispanic Hispanic, any race Other Education Elementarya High school, no diplomaa High school, diploma Any collegea Poverty status <100% FPL 100–124% FPL 125–199% FPL 200–399% FPL >399% FPL Employeda Health insurance Any privatea Public onlya Uninsureda Has drug insurancea Perceived health status Excellent Very good Good Fair Poor Medical conditionsa,c
Characteristic Sample size (n) Population size (N) Age (years) 18–39a 40–64
Table 2. Demographic and health characteristics of weighted samples: 2003–09
18.4 (17.5–19.4) 31.7 (30.6–32.8) 30.8 (29.7–31.9) 13.6 (12.9–14.4) 5.5 (4.9–6.0) 1.6 (1.5–1.6)
70.6 (69.3–72.0) 21.5 (20.3–22.6) 7.9 (7.3–8.5) 88.4 (87.7–89.2)
10.6 (9.8–11.4) 4.3 (3.8–4.8) 13.1 (12.1–14.0) 29.1 (27.9–30.3) 42.9 (41.2–44.5) 60.7 (59.2–62.1)
5.5 (4.9–6.0) 10.8 (10.1–11.5) 30.9 (29.6–32.2) 52.8 (51.3–54.4)
75.1 (73.4–76.9) 10.3 (9.1–11.5) 9.3 (8.2–10.4) 5.3 (4.3–6.3)
25.2 (23.7–26.7) 58.6 (57.8–59.5)
26.7 (25.4–27.9) 48.1 (46.9–49.4)
2008 % (95% CI) 12,235 136,945,056
17.4 (16.2–18.5) 32.4 (31.3–33.5) 31.8 (30.8–32.8) 13.5 (12.8–14.2) 4.9 (4.5–5.4) 1.6 (1.5–1.6)
70.2 (68.8–71.6) 21.7 (20.5–22.9) 8.1 (7.4–8.8) 89.3 (88.6–90.0)
11.1 (10.3–12.0) 4.4 (3.9–4.8) 12.8 (11.9–13.6) 29.5 (28.3–30.7) 42.2 (40.5–43.9) 58.4 (57.1–59.7)
5.2 (4.6–5.7) 10.9 (10.2–11.6) 30.9 (29.7–32.1) 53.0 (51.6–54.3)
75.4 (73.8–77.0) 10.0 (8.9–11.2) 9.4 (8.2–10.6) 5.1 (4.2–6.0)
25.7 (24.4–27.0) 59.0 (58.2–59.7)
26.5 (25.3–27.8) 47.8 (46.5–49.0)
2009 % (95% CI) 13,612 137,590,486
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Table 3. Weighted prevalence of number of pharmacies used: 2003–09 All pharmacy users (%) 1 pharmacy 2 pharmacies ≥3 pharmacies Multiple pharmacy users (%) 2 pharmacies ≥3 pharmacies
2003
2004
2005
2006
2007
2008
2009
63.6 27.6 8.7
62.5 27.8 9.7
62.6 27.7 9.8
62.1 28.4 9.5
62.3 28.8 8.9
59.0 30.3 10.8
56.8 30.6 12.6
75.9 24.1
74.0 26.0
73.9 26.1
75.1 24.9
76.5 23.5
73.8 26.2
70.9 29.1
2006
2007
2008
2009
66.5 33.4 27.3 17.7 1.8
67.1 33.5 27.0 15.6 1.7
71.2 36.3 26.2 15.1 1.7
70.7 41.5 25.0 15.9 1.9
33.7 9.0 4.3 2.0 0.2
34.4 9.2 3.7 2.5 0.2
37.3 11.6 4.5 2.5 0.2
34.6 12.1 3.6 2.2 0.3
18.3 3.4 2.0 1.2 0
16.2 4.4 1.3 1.0 0.1
25.6 5.4 2.2 0.7 0.4
23.1 6.2 2.4 0.6 0
Table 4. Weighted prevalence of use of pharmacy types by multiple pharmacy users: 2003–2009 2003 2004 2005 All multiple pharmacy users (%)a Community pharmacy 67.3 67.6 66.5 Other pharmacy 34.6 33.5 33.9 Mail service 21.9 25.7 28.9 HMO/clinic/hospital 17.8 17.1 16.8 Online 2.1 2.2 1.9 Multiple pharmacy users using 2 pharmacies of same type (%)b Multiple community pharmacies 35.0 35.4 34.1 Multiple other pharmacies 10.1 9.3 8.6 Multiple HMO/clinic/hospital pharmacies 3.7 3.5 4.4 Multiple mail service pharmacies 1.0 2.1 2.6 Multiple online pharmacies 0.3 0.3 0.4 Multiple pharmacy users using ≥3 pharmacies of same type (%)b Multiple community pharmacies 18.8 17.8 16.1 Multiple other pharmacies 3.9 3.2 2.4 Multiple HMO/clinic/hospital pharmacies 2.2 1.0 1.7 Multiple mail service pharmacies 0.8 0.7 0.7 Multiple online pharmacies 0.1 0.3 0
Abbreviation used: HMO, health maintenance organization. Community pharmacies include chain and independent. Other pharmacies include those located in mass merchandiser stores, grocery stores, or department stores. a Panel estimates include all respondents who used more than one pharmacy location. Because they could report the use of multiple pharmacy types (e.g., community, mail service), respondents may be included in more than one category; therefore, the percentages for each year do not total 100%. b Panel only includes individuals who used multiple pharmacies of the same type. For example, a respondent using multiple community pharmacies could be using a chain and an independent pharmacy.
ranging from a low of 49.2% in 2006 to a high of 56.1% in 2008. Among these respondents, community pharmacies were the most common pharmacy type used, followed by pharmacies located in another store. Among two-pharmacy users who reported using pharmacies of different types (data not shown), the most common pairs were a combination of a mail service pharmacy and community pharmacy (~14% per year), followed by a combination of a pharmacy located in another store and a community pharmacy (~13% per year). The bottom panel of Table 4 shows the use of pharmacies among multiple pharmacy users who reported using three or more pharmacies of the same type. Overall, between 2003 and 2009, the proportion of multiple pharmacy users using three or more pharmacies of the same type increased, ranging from a low of 20.9% in Journal of the American Pharmacists Association
2005 to a high of 34.3% in 2008. The most common type of pharmacy used by this population was community pharmacies, and the proportion exclusively using community pharmacies increased between 2003 and 2009. A majority of multiple pharmacy users who used three or more pharmacies were using a combination of different types of pharmacies.
Discussion This study describes MPU and the types of pharmacies used by multiple pharmacy users from 2003 to 2009 obtained from nationally representative samples of U.S. households. Of concern for pharmacists is the trend showing that MPU is becoming increasingly common on a national level, with more than two in five individuals reporting the use of more than one pharmacy in j apha.org
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2009. This is an important finding, as a lack of coordination between different pharmacy providers may have important safety, quality, and workload implications for pharmacists and their ability to deliver high-quality, efficient patient care, akin to the use of multiple physicians.1 It is unclear why MPU remained fairly stable from 2003 to 2007, then suddenly began to increase in 2008 and 2009, as no systematic changes occurred in the way MEPS collected or entered these data. One explanation for the increasing prevalence of MPU could be patients using coupons and $4 generic programs as they sought lower prices for their prescription drugs. Walmart established the first $4 prescription program in 2006 and expanded nationwide and to other pharmacy organizations shortly thereafter.31 Another contributing factor may be the increasing prevalence of prescription drug insurance seen during the study period. Further research examining the reasons patients use multiple pharmacies and factors contributing to the increasing rates of MPU is needed. The MPU rates found in this study are higher than a majority of estimates available in the literature for ambulatory adults in the United States (mean 26% [range 7.0–44.6]). The difference in results could be due to several factors, such as the time period, sample size, and patient population studied. However, our results are consistent with the MPU rate of 35.7% seen among Medicare beneficiaries in 2003.13 Our study is the first to examine MPU using nationally representative data for adults in the general U.S. population. Future research using these data could examine patient and system factors associated with MPU and examine MPU within specific patient populations (e.g., patients 65 years or older, the uninsured). The increasing trend in MPU could be due in part to increased use of mail service pharmacies by insurers and employers. Overall, the proportion of respondents using mail service pharmacies during the study period increased. The use of mail service pharmacy promotes MPU because patients use mail service pharmacies to obtain maintenance medications and use another local pharmacy to obtain acute medications. Across the study years, approximately 75% of mail service pharmacy users were multiple pharmacy users, such that they were about twice as likely to use multiple pharmacies compared with respondents who did not use a mail service pharmacy. MPU can result in increased workload for pharmacists because of the need to obtain medication profile information from all of the pharmacies used by patients. The greater the number of pharmacies used by a patient, the greater the potential degree of fragmentation of the medication profile and the greater the effort required by pharmacists to obtain up-do-date information. According to our results, a strong majority of multiple phar608 JAPhA | 5 3:6 | NOV/DEC 2013
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macy users were using only two pharmacies, implying limited fragmentation of medication information. However, as the prevalence of MPU increased in 2008 and 2009, the prevalence of multiple pharmacy users using more than two pharmacies also increased. Our study is the first to examine this aspect of multiple pharmacy use, and the trend in our results has important implications for pharmacists and should continue to be monitored. It will continue to be important for pharmacists to work with patients to identify other pharmacies that are used to obtain prescription medications. Examining the different types of pharmacies used by multiple pharmacy users is important, as it suggests the frequency of using pharmacies that potentially were electronically linked and thus may allow pharmacists to share patient medication information electronically across practice settings. For example, if a multiple pharmacy user is using two pharmacy types, an HMO/ clinic/hospital pharmacy and a community pharmacy (e.g., a Walgreens), these pharmacy types likely do not share medication profiles with one another. In addition, even if a multiple pharmacy user is using two community pharmacies, the pharmacies may (e.g., if they both are Walgreens) or may not (e.g., if one pharmacy is a Walgreens and the other is a CVS) share information. Our results across the study years showed that of multiple pharmacy users using only two pharmacies, roughly one-half were using a pair of pharmacies of the same type. Among multiple pharmacy users using more than two pharmacies, approximately 30% were using pharmacies of the same type. Taken together, less than one-half of all multiple pharmacy users were using pharmacies that had the potential to share information electronically. Given the variety of pharmacy ownership models within each pharmacy type category, the actual proportion of multiple pharmacy users using pharmacies that potentially are linked electronically was much lower. Strategies exist to help reduce unnecessary MPU at both the pharmacist and health system levels. Pharmacists can warn their patients of the potential risks of using multiple pharmacies and encourage them to consolidate their medications to one pharmacy or to the fewest number of pharmacies possible (e.g., one mail service pharmacy and one community pharmacy). In addition, pharmacists can ask patients to bring printouts listing all prescription and over-the-counter medications they currently are taking to each pharmacy visit. Pharmacists can then use the printouts to check for drug interactions against patients’ complete medication profiles. At the health system level, the use of electronic medication records (EMRs) that span across pharmacy organizations may be one way to ensure pharmacists are working with more complete patient medication profiles. Statewide prescription drug monitoring programs are examples of such initiatives; they have been estabJournal of the American Pharmacists Association
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lished in many states to improve patient care and safety and to reduce the abuse and diversion of prescription drugs. These programs contain information submitted to them by pharmacies and practitioners about monitored prescription drugs dispensed to patients in each state and provide pharmacists a more complete record of the use of these medications by patients. Other initiatives exist to share medical data among physicians and hospitals located in the same region across different organizations (e.g., when a patient is admitted to an emergency department). However, this may not be a complete fix, as any medications filled at pharmacies outside a shared EMR network still would be omitted from patients’ medication profiles. Given the nature of the MEPS data, identifying the pharmacy types that are under the same ownership or within the same health system is not possible. At a minimum, we can conclude that for a majority of multiple pharmacy users, pharmacists likely have to contact at least one additional pharmacy to obtain medication profile information. With the increasing trend of using more than two pharmacies, the burden of MPU on pharmacists likely is growing. Future research could explore the prevalence of multiple pharmacy users using pharmacies that have the ability to share information electronically by using, for example, prescription claims data that identify the name of the dispensing pharmacy. In addition, research could study the actual burden of MPU for pharmacists and explore the expansion of pharmacist access to electronic medical records and whether and how EMRs reduce the burden of MPU on pharmacists.
Limitations Our study had several limitations. First, we restricted our sample to respondents who had the opportunity to use multiple pharmacies (i.e., who had two or more prescription dispensations), whereas previous research has not made this distinction. A post hoc sensitivity analysis showed that this restriction resulted in a 3% to 4% higher rate of MPU than if all respondents were included. Second, the values for the type of pharmacy variables are determined solely by the household respondent and how they view the pharmacy establishment, with no definitions of the categories provided to the household respondents by MEPS interviewers (M.N. Stagnitti, personal e-mail communication, April 2010). Verification of these variables is not performed by MEPS personnel, resulting in general categories that do not provide details on the pharmacy locations (i.e., unable to divide community pharmacies into chain and independent pharmacies). Third, given the structure of the MEPS PM file, linking a specific medication fill with a particular pharmacy is not possible, which precludes analyses of the patterns Journal of the American Pharmacists Association
of MPU. Individuals may choose to patronize one main pharmacy while infrequently using additional pharmacies, for example, in an emergency, for an acute illness, or while traveling. These individuals may differ considerably in terms of health behaviors and outcomes from a person who uses multiple pharmacies on a consistent basis (e.g., individuals who routinely transfer their prescriptions to take advantage of coupons or promotions).
Conclusion The use of multiple pharmacies on a national level is common, and it increased between 2003 and 2009. These results have important implications for pharmacists and other health care providers, as they reinforce the fragmented nature of the medication use process. Although a majority of multiple pharmacy users used only two pharmacies, an increasing trend occurred in the use of three or more pharmacies. Further, our results examining the types of pharmacies used by multiple pharmacy users suggested that a majority of MPU occurred at pharmacies where medication profiles were likely not linked electronically. The results suggest that MPU may be requiring additional work for pharmacists to ensure complete and safe medication dispensing. Future research will further explore MPU and its relationship to patient characteristics and health outcomes. References 1. Shih A, Davis K, Schoenbaum S, et al. Organizing the U.S. health care delivery system for high performance. www.commonwealthfund.org/ Publications/Fund-Reports/2008/Aug/Organizing-the-U-S--HealthCare-Delivery-System-for-High-Performance.aspx. Accessed February 15, 2013. 2. Elhauge E. The fragmentation of U.S. health care: causes and solutions. New York: Oxford University Press; 2010. 3. Pham HH, Schrag D, O’Malley AS, et al. Care patterns in Medicare and their implications for pay for performance. N Engl J Med. 2007;356(11):1130–9. 4. Xu KT. Choice of and overall satisfaction with pharmacies among a community-dwelling elderly population. Med Care. 2002;40(12):1283–93. 5. McCombs JS, Nichol MB, Sclar DA. Single-pharmacy patronage and adverse drug reactions: a case study of cimetidine. J Res Pharmaceut Econ. 1993;5(1):3–24. 6. Gupta S, Rappaport HM, Bennett LT. Inappropriate drug prescribing and related outcomes for elderly Medicaid beneficiaries residing in nursing homes. Clin Ther. 1996;18(1):183–96. 7. Tamblyn RM, McLeod PJ, Abrahamowicz M, Laprise R. Do too many cooks spoil the broth? Multiple physician involvement in medical management of elderly patients and potentially inappropriate drug combinations. CMAJ. 1996;154(8):1177–84. 8. Kabat HF. Choice of source of pharmaceutical service. J Am Pharm Assoc. 1969;9(2):73–5. 9. Wu C, Bell CM, Wodchis WP. Incidence and economic burden of adverse drug reactions among elderly patients in Ontario emergency departments: a retrospective study. Drug Saf. 2012;35(9):769–81.
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10. Monane M, Bohn RL, Gurwitz JH, et al. The effects of initial drug choice and comorbidity on antihypertensive therapy compliance: results from a population-based study in the elderly. Am J Hypertens. 1997;10(7 pt 1):697–704. 11. Cocohoba JM, Althoff KN, Cohen M, et al. Pharmacist counseling in a cohort of women with HIV and women at risk for HIV. Patient Prefer Adherence. 2012;6:457–63. 12. Blake SG. The effect of the Louisianan Medicaid lock-in on prescription drug utilization and expenditures. Drug Benefit Trends. 1999;11(3):45–55. 13. Safran DG, Neuman P, Schoen C, et al. Prescription drug coverage and seniors: findings from a 2003 national survey. Health Aff (Millwood). 2005(suppl web exclusives):W5-152–66. 14. Liberman JN, Hutchins DS, Shrank WH, et al. Adherence to medication under mandatory and voluntary mail benefit designs. Am J Manag Care. 2011;17(7):e260–9. 15. Pharmacy Benefit Management Institute. Prescription drug benefit cost and plan design report: 2012-2013. www.benefitdesignreport. com. Accessed February 12, 2013. 16. Wiederholt JB. Development of an instrument to measure evaluative criteria that patients use in selecting a pharmacy for obtaining prescription drugs. J Pharm Mark Manage. 1987;1(4):35–59.
23. Jamaldinian M. Can a drug coupon put you at risk? www.consumerhealth.com/services/cons_take71.php. Accessed February 12, 2013. 24. Fulda TR, Lyles A, Pugh MC, Christensen DB. Current status of prospective drug utilization review. J Manag Care Pharm. 2004;10(5):433–41. 25. Shepherd MD, Crawford SY. An investigation of what factors are important to the elderly in selecting a pharmacy and purchasing drug products. J Pharm Mark Manage. 1987;2(1):63–82. 26. Lipowski EE. Predictors of community pharmacy preference: a logistic regression analysis of consumers’ socioeconomic and shopping characteristics. J Pharm Mark Manage. 1991;6(2):43–61. 27. Franic DM, Haddock SM, Tucker LT, et al. Pharmacy patronage: identifying key factors in the decision making process using the determinant attribute approach. J Am Pharm Assoc. 2008;48(1):71–85. 28. Ostrom JR, Hammarlund ER, Christensen DB, et al. Medication usage in an elderly population. Med Care. 1985;23(2):157–64. 29. Ezzati-Rice TM, Rohde F, Greenblatt J. Sample design of the Medical Expenditure Panel Survey Household Component, 1998–2007. Methodology report no. 22. Rockville, MD: Agency for Healthcare Research & Quality; 2008. 30. Royston P. Multiple imputation of missing values. Stata Journal. 2004;4(3):227–41.
17. Stergachis A, Maine LL, Brown L. The 2001 National Pharmacy Consumer Survey. J Am Pharm Assoc. 2002;42(4):568–76.
31. Walmart. 2007 annual report. http://stock.walmart.com/annual-reports. Accessed February 15, 2013.
18. Gagnon JP. Factors affecting pharmacy patronage motives: a literature review. J Am Pharm Assoc. 1977;17(9):556–9, 566.
32. Raffoul PR, Cooper JK, Love DW. Drug misuse in older people. Gerontologist. 1981;21(2):146–50.
19. Laverty RF. Patients loyal but need more Rx information. Drug Topics. 1984;128:35–40, 42–5.
33. Ranelli PL, Coward RT. Residential differences in the use of pharmacies by older adults and their communication experiences with pharmacists. J Rural Health. 1996;12(1):19–32.
20. Schommer JC. The effect of age on pharmacy patronage: is locational convenience a lurking variable? J Pharm Mark Manage. 1994;9(1):33– 46. 21. Metge CJ, Hendricksen C, Maine L. Consumer attitudes, behaviors, and perceptions about pharmacies, pharmacists, and pharmaceutical care. J Am Pharm Assoc. 1998;38(1):37–47.
34. Polinski JM, Schneeweiss S, Levin R, Shrank WH. Completeness of retail pharmacy claims data: implications for pharmacoepidemiologic studies and pharmacy practice in elderly patients. Clin Ther. 2009;31(9):2048–59.
22. Franic DM, Grauer DW, Law AV. An evaluation of patients’ attitudes toward pharmacy selection: a determinant attribute approach. J Pharm Mark Manage. 2005;17(1):35–50.
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Multiple pharmacy use and types of pharmacies used to obtain prescriptions Kevin A. Look and David A. Mott Received February 20, 2013, and in revised form May 5, 2013. Accepted for publication June 11, 2013.
Abstract Objectives: To evaluate trends and patterns in the prevalence of multiple pharmacy use (MPU) and to describe the number and types of pharmacies used by multiple pharmacy users from 2003 to 2009. Design: Retrospective, cross-sectional, descriptive study. Setting: United States from 2003 to 2009. Participants: 89,941 responses to the Medical Expenditure Panel Survey over 7 years. Intervention: Analysis of respondent pharmacy use behaviors. Main outcome measures: Annual use of more than one pharmacy and number and types of pharmacies used. Results: MPU among patients using medications increased significantly during the study period (from 36.4% [95% CI 35.2–37.6] in 2003 to 43.2% [41.9–44.4] in 2009)—a relative increase of 18.7% (P = 0.01). Multiple pharmacy users used between 2 and 17 different pharmacies per year to obtain prescription medications. Although approximately 70% of multiple pharmacy users used only two pharmacies, the proportion using three or more pharmacies increased from 24.1% (22.5–25.7) in 2003 to 29.1% (27.4–30.8) in 2009. Mail service pharmacy use had the largest relative increase among multiple pharmacy users during the study period (27.2%), and MPU was nearly twice as high (75%) among mail service users compared with non– mail service users.
Kevin A. Look, PharmD, MS, is a PhD candidate and American Foundation for Pharmaceutical Education Fellow; and David A. Mott, PhD, is Hammel/Sanders Distinguished Professor and Division Chair, School of Pharmacy, University of Wisconsin–Madison. Correspondence: Kevin A. Look, PharmD, MS, School of Pharmacy, University of Wisconsin, 777 Highland Ave., Madison, WI 53705-2222. Fax: 608-262-5262. E-mail: [email protected] Disclosure: Dr. Look is supported by an American Foundation for Pharmaceutical Education Predoctoral Fellowship. The authors declare no conflicts of interest or financial interests in any product or service mentioned in this article, including grants, employment, gifts, stock holdings, or honoraria. Previous presentation: American Pharmacists Association Annual Meeting & Exposition, New Orleans, LA, March 9–12, 2012; and Midwest Social and Administrative Pharmacy Conference, Madison, WI, August 8–10, 2012. Published online ahead of print at www. japha.org on October 4, 2013.
Conclusion: MPU is common on a national level and has increased greatly in recent years. Patient use of pharmacies that have the potential to share medication information electronically is low among multiple pharmacy users, suggesting increased workload for pharmacists and potential medication safety concerns. This has important implications for pharmacists, as it potentially impedes their ability to maintain accurate medication profiles for patients. Keywords: Multiple pharmacy use, pharmacy types, pharmacy patronage. J Am Pharm Assoc. 2013;53:601–610. doi: 10.1331/JAPhA.2013.13040
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T
he U.S. health care system has long been characterized as a fragmented system that delivers poor-quality, high-cost care lacking coordination among different providers that a patient might see.1,2 The use of multiple physicians has long been a concern, as Medicare beneficiaries see a median of two primary care physicians and five specialists working in four different practices in a single year.3 This fragmentation leads to frustrating and dangerous patient experiences, waste and duplication, and medical errors, hindering providers’ ability to deliver high-quality, efficient patient care.1 Multiple pharmacy use (MPU) is an analogous and important safety and quality issue for pharmacists and patients. MPU occurs when an individual obtains prescription drugs from more than one pharmacy location and stems from a patient’s experience and satisfaction with different pharmacies.4 MPU can result in fragmented patient care because pharmacists may not have access to the medications dispensed at other pharmacies. This decreases pharmacists’ ability to monitor for drug interactions and provide appropriate patient consultation.4–7 MPU has been linked to many undesirable outcomes affecting patient safety or quality of care, including inappropriate drug use and adverse drug reactions,7–9 de-
At a Glance Synopsis: An analysis of data from the Medical Expenditure Panel Survey showed that multiple pharmacy use (MPU) increased from 36.4% in 2003 to 43.2% in 2009—a relative increase of 18.7%. Although approximately 70% of multiple pharmacy users used only two pharmacies per year, the proportion using three or more pharmacies increased by 20.7% from 2003 to 2009. Approximately 75% of patients who used mail service pharmacy were multiple pharmacy users. Analysis: Of concern for pharmacists is the trend showing that MPU is becoming increasingly common on a national level, with more than two in five individuals reporting the use of more than one pharmacy in 2009. In addition, the use of three or more pharmacies increased. The increasing trend in MPU could be a result of increased use of mail service pharmacies by insurers and employers, as respondents who used a mail service pharmacy were about twice as likely to use multiple pharmacies compared with respondents who did not use mail service pharmacy. These results suggest that a majority of patients using multiple pharmacies are using pharmacies where medication profiles are not linked electronically. This lack of coordination among different pharmacy providers can result in increased workload for pharmacists, as well as important safety and quality concerns.
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creased patient adherence,10,11 increased mortality,6 and an increase in ambulatory care and hospital expenditures.5,6,12 The prevalence of MPU and the number of pharmacies used likely is associated with several changing trends in the U.S. health care system. Access to employer-based prescription drug insurance has reduced the impact of price as a barrier to medication use and may be associated with higher rates of MPU.13 Mail service pharmacy increasingly is being used as a cost-saving measure for insurers and employers.14 In 2012, 93% of employers offered access to a mail service pharmacy for maintenance medications and 23% of employers had mandatory mail service plans (5% increase from 2011).15 In addition, pharmacy location and convenience to a patient’s home, work, or medical providers are consistently rated as one of the most important reasons for selecting a pharmacy,16–22 which could result in increased MPU when patients select the most convenient pharmacy to obtain a medication rather than patronizing one pharmacy provider. The fact that certain pharmacy types (e.g., community chain pharmacies) use linked computer systems that enable medication profiles to be shared electronically across stores also may promote MPU. A final contributing factor is the use of incentives by pharmacies to encourage patients to transfer prescriptions among pharmacy corporations.23 The number and type of pharmacies used by multiple pharmacy users have important implications for pharmacists. When patients use multiple pharmacies having a centralized computing system that allows pharmacists at different sites to share patient medication profiles electronically (e.g., pharmacies from the same community chain, group of independent pharmacies), it is easier for pharmacists to link fragmented medication profiles that exist across multiple pharmacies. However, when patients use multiple types of pharmacies that are not linked electronically, and thus do not share patient medication profile information electronically (e.g., multiple independent or community pharmacies, multiple health systems, mail service pharmacies in combination with community pharmacies), patients may be at highest risk of harmful effects resulting from pharmacists’ inability to review and maintain a complete and current medication profile.4–7 When this occurs, pharmacists must spend additional time coordinating with the patients’ other pharmacies to link fragmented medication profiles, likely adding to pharmacist workload and stress. Prospective drug use review (PDUR) systems may provide a limited safety net for patients with drug insurance that use multiple pharmacy types that are not electronically linked. Although PDUR systems communicate potential drug–drug interactions and other drug use warnings to dispensing pharmacists via a centralized claims processing system, the interaction checks often are incomplete and do not account for prescriptions that are obtained outside the insurance plan (e.g., cash prescriptions, $4 Journal of the American Pharmacists Association
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generics).24 In addition, such a system does not exist for individuals without drug insurance. Little is known on a national level about trends in the prevalence of MPU or the number and types of pharmacies used by patients who visit multiple pharmacies. A total of 14 studies were identified that included any estimate of the prevalence of MPU (Table 1), with even fewer describing the types of pharmacies used. In addition, only four studies have included information on the total number of pharmacies used by the study sample. MPU estimates among noninstitutionalized adults have ranged from 7.0% to 44.6% (mean 26%) and have varied considerably depending on patient population, sample size, geographic location of participants, time period, and methods and instruments used for data collection.16,25–28 An additional limitation is that few recent studies have estimated the prevalence of MPU. To date, only two studies that included MPU estimates were performed using national data. A telephone survey of households located throughout the continental United States found that patients rarely used more than one (72%) or two (24%) pharmacies on a regular basis in 1996.21 The second study, a nationally representative survey of Medicare beneficiaries, found that 35.7% used more than one pharmacy in 2003.13 To the authors’ knowledge, no studies have been performed using large datasets representative of the general U.S. population, have shown trends in the prevalence of MPU over time, or have provided information about the number and type
of pharmacies patronized by multiple pharmacy users. Information about MPU is useful because of the potential burden that MPU places on pharmacists. Because little is known about MPU, identifying how commonly it occurs is important to determining the scope of the issue. In addition, evaluating information on the types of pharmacies used by multiple pharmacy users can help to inform strategies to limit the effects of MPU on pharmacist quality of care and patient safety.
Objectives This study sought to evaluate trends and patterns in the prevalence of MPU and to describe the number and types of pharmacies used by multiple pharmacy users to obtain prescription drugs from 2003 to 2009. Multiple years of respondent data obtained from a nationally representative survey of health care use, expenditures, sources of payment, and health insurance were analyzed. Data were obtained using consistent measures over time, in order to provide more reliable estimates of MPU than previously reported.
Methods This study used data from the Medical Expenditure Panel Survey (MEPS). Conducted annually by the Agency for Healthcare Research & Quality since 1996, MEPS provides nationally representative estimates of health care use, expenditures, sources of payment, and health insurance coverage for the U.S. civilian noninstitutional-
Table 1. Summary of studies estimating the prevalence of multiple pharmacy use Study Kabat8 Raffoul et al.32 Laverty19 Ostrom et al.28 Shepherd and Crawford McCombs et al.5 Ranelli and Coward33 Monane et al.10
25
Metge et al.21 Stergachis et al.17 Xu4 Safran et al.13 Polinski et al.34 Cocohoba et al.11
Study population Adult pedestrians in Minnesota Random sample of registered voters age ≥60 years in Fayette County, KY Consumer families demographically balanced to be representative of the U.S. population Low-income older and disabled individuals (≥60 years) living in two federally supported Seattle high rises Systematic random sample of older (≥60 years) Texas residents 5% sample of California Medicaid recipients who used cimetidine Random sample of older adults (≥60 years) in Florida Older (≥60 years) New Jersey Medicaid enrollees newly started on antihypertensive drug Random sample of households in the continental U.S. Random sample of households in the continental U.S. that filled at least one prescription in the previous 6 months Older individuals (≥60 years) in West Texas 1% national probability sample of noninstitutionalized Medicare beneficiaries (≥60 years) Older individuals (≥60 years) enrolled in the PACE program in Pennsylvania Cohort of women with HIV or at risk for HIV receiving pharmacist counseling
Sample size (n) 1,400 67
Using multiple pharmacies (%) 44.6 20.9
~1,500a
22.0
183 509 2,862 400
25.0b 37.9 18.5 14.3
8,643 984
21.0 28.0
1,201 2,545
26.0 23.3
17,685 182,116 783
35.7 21.7 24.0
Abbreviations used: HIV, human immunodeficiency virus; PACE, Pharmaceutical Assistance Contract for the Elderly. a Exact sample size not given. a Although 93% of the residents patronized a single pharmacy for prescription service, one-fourth had used more than one pharmacy in the previous year. Journal of the American Pharmacists Association
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ized population.29 MEPS collects information about each household member as reported by a single household respondent and uses an overlapping panel design, collecting data for respondents via five rounds of interviews during a 2.5-year period. We used the Household Component of the MEPS, which includes detailed information on health care use and expenditures, health status, health insurance coverage, and demographics. We also used the Prescribed Medicines (PM) file, which includes information on every acquisition of a prescribed medication reported by household respondents during the calendar year. The PM file contains detailed information on the medication acquired, including associated medical conditions (if any), sources of payment, and types of pharmacies from which medications were obtained. The sample included community-dwelling adults from 2003 through 2009. We excluded children younger than 18 years because parents or caregivers likely dictated their pharmacy selection. We restricted our sample to respondents who had two or more medications dispensed (i.e., opportunity to use multiple pharmacies). A medication dispensation was defined as each acquisition of a new prescription or a refill of an existing prescription. The study sample consisted of seven cross-sectional samples in consecutive years, ranging from 12,938 in 2003 to 13,612 in 2009. When nationally representative survey weights were applied, the weighted population size ranged from 129,366,234 individuals in 2003 to 137,590,486 individuals in 2009.
Study variables MPU, the number of pharmacies used, and types of pharmacies used by MEPS respondents were determined using the variables that described the type of pharmacy respondents used to obtain medications. MEPS respondents were asked to report the name and location of each pharmacy from which they obtained prescription medications. Each unique pharmacy location used by the respondent is included in the PM file as a separate variable (numbered sequentially from 1 to n), such that each different location of a pharmacy organization is treated as a separate pharmacy (M.N. Stagnitti, personal e-mail communication, April 2010). That is, a person who obtained medications from three separate locations within the same community pharmacy chain would have three separate variables in the dataset. These “type of pharmacy” variables (PHARTP1 to PHARTPn) represented all of the pharmacy providers from whom a patient’s medications were obtained during the survey year. Because every pharmacy location is entered as a separate variable, we defined the number of PHARTP variables with nonmissing values as the total number of pharmacies used by that respondent. We classified MPU as occurring when a respondent used more than one pharmacy location. The additional information about each pharmacy reported in the PHARTP variables was obtained in response to the question, “What type of pharmacy is that? Is it a mail-order pharmacy; a pharmacy located in another store such as a grocery or department store; a pharmacy located in an HMO [health maintenance or-
Prevalence of multiple pharmacy use
44% 43% 42% 41% 40% 39% 38% 37% 36% 35% 2003
2004
2005
2006
2007
2008
2009
Year
Figure 1. National prevalence of multiple pharmacy use: 2003–09 Estimates weighted to represent the national adult noninstitutionalized population.
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ganization], clinic, or hospital; a drug store that is not located within another facility; or is it an on-line pharmacy?” Because information about the type of pharmacy was obtained via self-report and no definitions were provided by MEPS personnel, the PHARTP variables reflected MEPS respondents’ perceptions of the types of pharmacies used. Of important note, two respondents may report different pharmacy types for the same pharmacy location. Although respondents were asked to report the pharmacy name and location, the pharmacy names documented by MEPS interviewers are not released to the public. As such, grouping the pharmacies used by a respondent by type, corporate owner, or health system was not possible. This precluded examining whether a patient used pharmacies that are able to link medication profiles electronically across different pharmacy locations. Thus, we report the types of pharmacies used by respondents using the predetermined categories described above and contained in the MEPS PM file. Statistical analyses The ICE command30 in Stata 11 (Stata, College Station, TX) was used to impute missing data that remained after data cleaning and editing by MEPS personnel. The ICE procedure uses the switching regression method, which incorporates nonmissing data into a series of linear or logistic regressions for each observation to generate plausible values for the missing data. Less than 4% of all observations had missing values, with no variable having more than 2% of values missing. All demographic and health characteristics variables were included to maximize available information for the imputation and to minimize bias. The imputed data were used for all analyses, and yearly MEPS person-level weight variables were used to account for the complex sampling strategy and to make nationally representative estimates for the civilian noninstitutionalized U.S. population for each year. We calculated descriptive statistics for each sample for each study year. Variables included age, gender, race and Hispanic ethnicity, education, poverty status, employment status, health insurance, drug insurance, perceived health status, and number of medical conditions. T tests and chi-squared tests were used to test for differences in demographics and health characteristics between the 2003 and 2009 samples. MPU rates and the number of pharmacies used were calculated with 95% CIs from 2003 to 2009, and linear regression was used to test for statistically significant linear trends in MPU. An alpha of P < 0.05 was used to determine statistical significance. The frequency of using each type of pharmacy across the study years was determined. This study was granted exemption status by the University of Wisconsin Health Sciences Institutional Review Board.
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Results The demographic and health characteristics of the sample population remained stable between 2003 and 2009, with the exception of insurance coverage and employment status (Table 2). Consistent with an economic recession, employment status and the proportion of respondents who reported having private health insurance decreased, with corresponding increases in the rates of public health insurance and being uninsured. However, the proportion of respondents with prescription drug insurance increased every year, rising from 79.8% in 2003 (95% CI 78.8–80.7) to 89.3% in 2009 (88.6– 90.0). Across the study years, individuals who used multiple pharmacies were more likely to be 65 years or older, be female, be white, be unemployed, have drug insurance, have lower perceived health status, and have a higher number of medical conditions. Figure 1 shows the weighted annual prevalence of MPU among noninstitutionalized adults in the United States from 2003 to 2009. A statistically significant increase in MPU occurred during the study period (from 36.4% in 2003 [35.2–37.6] to 43.2% in 2009 [41.9–44.4]; P < 0.001). The prevalence increased sharply in 2008 and 2009 despite no systematic changes in the way variables related to MPU were collected or measured. The prevalence of MPU increased by 6.8% (5.0–8.4; P < 0.001) during the study period—a relative increase of 18.7%. Multiple pharmacy users reported patronizing between 2 and 17 different pharmacies per year, with approximately 70% using only two pharmacies per year (Table 3). The proportion of multiple pharmacy users who reported using three or more pharmacies increased significantly from 24.1% (95% CI 22.5–25.7) in 2003 to 29.1% (27.4–30.8) in 2009 (P < 0.001). The prevalence of using three or more pharmacies increased significantly (by 5% [2.7–7.3]; P < 0.001) during the study period, which represents a 20.7% relative increase. Table 4 shows the types of pharmacies used by respondents who reported using multiple pharmacies. The top panel shows that between 2003 and 2009, an increase occurred in the proportion of multiple pharmacy users using community pharmacies (i.e., chain and independent), pharmacies located in another store (i.e., pharmacies located in mass merchandiser stores, grocery stores, or department stores), and mail service pharmacies. When these data are combined with similar data for single pharmacy users (data not shown) across the study years, approximately 75% of mail service pharmacy users and nearly 90% of online pharmacy users were multiple pharmacy users. The second panel of Table 4 shows the use of pharmacies among multiple pharmacy users who reported using only two pharmacies that were of the same type. Overall, across the study years, approximately onehalf of individuals who reported using two pharmacies used pharmacies of the same type, with the proportion j apha.org
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24.8 (23.5–26.0) 60.1 (59.3–60.8) 76.5 (75.1–78.0) 9.8 (8.8–10.8) 8.4 (7.6–9.3) 5.2 (4.5–5.9) 6.5 (6.0–7.0) 11.7 (11.0–12.4) 32.3 (31.2–33.4) 49.5 (48.2–50.9) 10.5 (9.7–11.2) 4.1 (3.6–4.5) 13.1 (12.2–13.9) 29.9 (28.7–31.2) 42.4 (40.8–44.0) 60.9 (59.7–62.1) 75.1 (73.9–76.3) 18.4 (17.4–19.4) 6.5 (5.9–7.0) 80.9 (80.0–81.8) 18.1 (17.1–19.0) 31.2 (30.1–32.2) 31.7 (30.6–32.7) 13.5 (12.8–14.3) 5.6 (5.1–6.1) 1.2 (1.2–1.3)
76.9 (75.6–78.3) 10.1 (9.2–11.0) 8.1 (7.2–8.9) 4.9 (4.2–5.5)
7.1 (6.5–7.8) 12.5 (11.7–13.4) 32.2 (31.1–33.3) 48.1 (46.6–49.6)
10.6 (9.8–11.3) 4.2 (3.7–4.7) 13.2 (12.4–14.0) 29.3 (28.1–30.5) 42.7 (41.1–44.3) 61.1 (59.8–62.4)
75.5 (74.3–76.7) 18.0 (17.0–19.0) 6.5 (5.8–7.1) 79.8 (78.8–80.7)
18.2 (17.2–19.3) 31.9 (30.8–33.0) 31.2 (30.1–32.2) 13.3 (12.5–14.2) 5.3 (4.8–5.8) 1.2 (1.2–1.3)
28.6 (27.5–29.7) 46.6 (45.4–47.8)
2004 % (95% CI) 12,961 130,242,252
24.5 (23.1–25.9) 60.2 (59.4–61.0)
29.1 (27.9–30.3) 46.4 (45.1–47.8)
2003 % (95% CI) 12,938 129,366,234
18.5 (17.4–19.6) 31.9 (30.7–33.0) 31.0 (30.0–32.0) 13.3 (12.5–14.1) 5.3 (4.8–5.8) 1.3 (1.2–1.3)
74.6 (73.4–75.8) 18.2 (17.2–19.3) 7.2 (6.6–7.7) 84.6 (83.8–85.3)
10.4 (9.7–11.1) 4.0 (3.5–4.5) 12.9 (12.0–13.7) 29.8 (28.6–31.0) 42.9 (41.3–44.6) 60.8 (59.5–62.1)
6.1 (5.6–6.7) 11.9 (11.1–12.6) 31.7 (30.6–32.9) 50.3 (48.7–51.8)
75.9 (74.4–77.4) 10.0 (9.0–11.0) 8.8 (7.8–9.7) 5.3 (4.6–6.0)
24.4 (23.3–25.6) 59.8 (59.0–60.6)
28.4 (27.3–29.6) 47.1 (45.9–48.4)
2005 % (95% CI) 12,925 133,290,595
17.8 (16.8–18.7) 32.4 (31.3–33.6) 31.8 (30.7–32.9) 12.9 (12.2–13.6) 5.1 (4.7–5.6) 1.3 (1.2–1.3)
74.1 (73.0–75.3) 18.7 (17.6–19.8) 7.2 (6.7–7.7) 86.5 (85.8–87.3)
10.4 (9.6–11.1) 4.6 (4.2–5.1) 11.9 (11.1–12.7) 29.3 (28.2–30.4) 43.8 (42.3–45.3) 61.5 (60.2–62.8)
6.3 (5.7–6.8) 11.4 (10.7–12.1) 30.8 (29.6–32.0) 51.5 (50.0–53.1)
75.5 (73.9–77.2) 10.2 (9.1–11.2) 9.1 (8.2–10.0) 5.2 (4.4–5.9)
24.9 (23.8–26.0) 59.3 (58.4–60.2)
28.2 (27.0–29.5) 46.9 (45.7–48.0)
2006 % (95% CI) 13,263 133,224,180
18.5 (17.4–19.5) 31.3 (30.2–32.4) 32.1 (31.0–33.2) 13.4 (12.7–14.1) 4.7 (4.3–5.1) 1.4 (1.3–1.4)
72.7 (71.5–73.9) 20.1 (19.1–21.1) 7.3 (6.7–7.9) 86.6 (85.9–87.4)
10.7 (9.9–11.4) 4.1 (3.7–4.6) 12.2 (11.4–13.0) 29.0 (27.8–30.2) 44.0 (42.5–45.5) 61.5 (60.3–62.7)
6.0 (5.5–6.5) 11.2 (10.6–11.9) 30.5 (29.3–31.8) 52.2 (50.8–53.7)
74.9 (73.5–76.4) 10.4 (9.4–11.4) 9.3 (8.4–10.2) 5.4 (4.7–6.1)
24.9 (23.8–26.0) 58.9 (58.1–59.7)
27.6 (26.4–28.8) 47.5 (46.3–48.7)
2007 % (95% CI) 12,007 133,800,147
Abbreviation used: FPL, federal poverty level. Estimates weighted to represent the national adult noninstitutionalized population. a P < 0.01, 2003 vs. 2009. b P < 0.005, 2003 vs. 2009. c Medical conditions included high blood pressure, coronary heart disease, angina, myocardial infarction, other unspecified heart disease, stroke, emphysema, diabetes, arthritis, and asthma.
≥65 Womenb Race/ethnicity White, non-Hispanic Black, non-Hispanic Hispanic, any race Other Education Elementarya High school, no diplomaa High school, diploma Any collegea Poverty status <100% FPL 100–124% FPL 125–199% FPL 200–399% FPL >399% FPL Employeda Health insurance Any privatea Public onlya Uninsureda Has drug insurancea Perceived health status Excellent Very good Good Fair Poor Medical conditionsa,c
Characteristic Sample size (n) Population size (N) Age (years) 18–39a 40–64
Table 2. Demographic and health characteristics of weighted samples: 2003–09
18.4 (17.5–19.4) 31.7 (30.6–32.8) 30.8 (29.7–31.9) 13.6 (12.9–14.4) 5.5 (4.9–6.0) 1.6 (1.5–1.6)
70.6 (69.3–72.0) 21.5 (20.3–22.6) 7.9 (7.3–8.5) 88.4 (87.7–89.2)
10.6 (9.8–11.4) 4.3 (3.8–4.8) 13.1 (12.1–14.0) 29.1 (27.9–30.3) 42.9 (41.2–44.5) 60.7 (59.2–62.1)
5.5 (4.9–6.0) 10.8 (10.1–11.5) 30.9 (29.6–32.2) 52.8 (51.3–54.4)
75.1 (73.4–76.9) 10.3 (9.1–11.5) 9.3 (8.2–10.4) 5.3 (4.3–6.3)
25.2 (23.7–26.7) 58.6 (57.8–59.5)
26.7 (25.4–27.9) 48.1 (46.9–49.4)
2008 % (95% CI) 12,235 136,945,056
17.4 (16.2–18.5) 32.4 (31.3–33.5) 31.8 (30.8–32.8) 13.5 (12.8–14.2) 4.9 (4.5–5.4) 1.6 (1.5–1.6)
70.2 (68.8–71.6) 21.7 (20.5–22.9) 8.1 (7.4–8.8) 89.3 (88.6–90.0)
11.1 (10.3–12.0) 4.4 (3.9–4.8) 12.8 (11.9–13.6) 29.5 (28.3–30.7) 42.2 (40.5–43.9) 58.4 (57.1–59.7)
5.2 (4.6–5.7) 10.9 (10.2–11.6) 30.9 (29.7–32.1) 53.0 (51.6–54.3)
75.4 (73.8–77.0) 10.0 (8.9–11.2) 9.4 (8.2–10.6) 5.1 (4.2–6.0)
25.7 (24.4–27.0) 59.0 (58.2–59.7)
26.5 (25.3–27.8) 47.8 (46.5–49.0)
2009 % (95% CI) 13,612 137,590,486
RESEARCH MULTIPLE PHARMACY USE
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Table 3. Weighted prevalence of number of pharmacies used: 2003–09 All pharmacy users (%) 1 pharmacy 2 pharmacies ≥3 pharmacies Multiple pharmacy users (%) 2 pharmacies ≥3 pharmacies
2003
2004
2005
2006
2007
2008
2009
63.6 27.6 8.7
62.5 27.8 9.7
62.6 27.7 9.8
62.1 28.4 9.5
62.3 28.8 8.9
59.0 30.3 10.8
56.8 30.6 12.6
75.9 24.1
74.0 26.0
73.9 26.1
75.1 24.9
76.5 23.5
73.8 26.2
70.9 29.1
2006
2007
2008
2009
66.5 33.4 27.3 17.7 1.8
67.1 33.5 27.0 15.6 1.7
71.2 36.3 26.2 15.1 1.7
70.7 41.5 25.0 15.9 1.9
33.7 9.0 4.3 2.0 0.2
34.4 9.2 3.7 2.5 0.2
37.3 11.6 4.5 2.5 0.2
34.6 12.1 3.6 2.2 0.3
18.3 3.4 2.0 1.2 0
16.2 4.4 1.3 1.0 0.1
25.6 5.4 2.2 0.7 0.4
23.1 6.2 2.4 0.6 0
Table 4. Weighted prevalence of use of pharmacy types by multiple pharmacy users: 2003–2009 2003 2004 2005 All multiple pharmacy users (%)a Community pharmacy 67.3 67.6 66.5 Other pharmacy 34.6 33.5 33.9 Mail service 21.9 25.7 28.9 HMO/clinic/hospital 17.8 17.1 16.8 Online 2.1 2.2 1.9 Multiple pharmacy users using 2 pharmacies of same type (%)b Multiple community pharmacies 35.0 35.4 34.1 Multiple other pharmacies 10.1 9.3 8.6 Multiple HMO/clinic/hospital pharmacies 3.7 3.5 4.4 Multiple mail service pharmacies 1.0 2.1 2.6 Multiple online pharmacies 0.3 0.3 0.4 Multiple pharmacy users using ≥3 pharmacies of same type (%)b Multiple community pharmacies 18.8 17.8 16.1 Multiple other pharmacies 3.9 3.2 2.4 Multiple HMO/clinic/hospital pharmacies 2.2 1.0 1.7 Multiple mail service pharmacies 0.8 0.7 0.7 Multiple online pharmacies 0.1 0.3 0
Abbreviation used: HMO, health maintenance organization. Community pharmacies include chain and independent. Other pharmacies include those located in mass merchandiser stores, grocery stores, or department stores. a Panel estimates include all respondents who used more than one pharmacy location. Because they could report the use of multiple pharmacy types (e.g., community, mail service), respondents may be included in more than one category; therefore, the percentages for each year do not total 100%. b Panel only includes individuals who used multiple pharmacies of the same type. For example, a respondent using multiple community pharmacies could be using a chain and an independent pharmacy.
ranging from a low of 49.2% in 2006 to a high of 56.1% in 2008. Among these respondents, community pharmacies were the most common pharmacy type used, followed by pharmacies located in another store. Among two-pharmacy users who reported using pharmacies of different types (data not shown), the most common pairs were a combination of a mail service pharmacy and community pharmacy (~14% per year), followed by a combination of a pharmacy located in another store and a community pharmacy (~13% per year). The bottom panel of Table 4 shows the use of pharmacies among multiple pharmacy users who reported using three or more pharmacies of the same type. Overall, between 2003 and 2009, the proportion of multiple pharmacy users using three or more pharmacies of the same type increased, ranging from a low of 20.9% in Journal of the American Pharmacists Association
2005 to a high of 34.3% in 2008. The most common type of pharmacy used by this population was community pharmacies, and the proportion exclusively using community pharmacies increased between 2003 and 2009. A majority of multiple pharmacy users who used three or more pharmacies were using a combination of different types of pharmacies.
Discussion This study describes MPU and the types of pharmacies used by multiple pharmacy users from 2003 to 2009 obtained from nationally representative samples of U.S. households. Of concern for pharmacists is the trend showing that MPU is becoming increasingly common on a national level, with more than two in five individuals reporting the use of more than one pharmacy in j apha.org
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2009. This is an important finding, as a lack of coordination between different pharmacy providers may have important safety, quality, and workload implications for pharmacists and their ability to deliver high-quality, efficient patient care, akin to the use of multiple physicians.1 It is unclear why MPU remained fairly stable from 2003 to 2007, then suddenly began to increase in 2008 and 2009, as no systematic changes occurred in the way MEPS collected or entered these data. One explanation for the increasing prevalence of MPU could be patients using coupons and $4 generic programs as they sought lower prices for their prescription drugs. Walmart established the first $4 prescription program in 2006 and expanded nationwide and to other pharmacy organizations shortly thereafter.31 Another contributing factor may be the increasing prevalence of prescription drug insurance seen during the study period. Further research examining the reasons patients use multiple pharmacies and factors contributing to the increasing rates of MPU is needed. The MPU rates found in this study are higher than a majority of estimates available in the literature for ambulatory adults in the United States (mean 26% [range 7.0–44.6]). The difference in results could be due to several factors, such as the time period, sample size, and patient population studied. However, our results are consistent with the MPU rate of 35.7% seen among Medicare beneficiaries in 2003.13 Our study is the first to examine MPU using nationally representative data for adults in the general U.S. population. Future research using these data could examine patient and system factors associated with MPU and examine MPU within specific patient populations (e.g., patients 65 years or older, the uninsured). The increasing trend in MPU could be due in part to increased use of mail service pharmacies by insurers and employers. Overall, the proportion of respondents using mail service pharmacies during the study period increased. The use of mail service pharmacy promotes MPU because patients use mail service pharmacies to obtain maintenance medications and use another local pharmacy to obtain acute medications. Across the study years, approximately 75% of mail service pharmacy users were multiple pharmacy users, such that they were about twice as likely to use multiple pharmacies compared with respondents who did not use a mail service pharmacy. MPU can result in increased workload for pharmacists because of the need to obtain medication profile information from all of the pharmacies used by patients. The greater the number of pharmacies used by a patient, the greater the potential degree of fragmentation of the medication profile and the greater the effort required by pharmacists to obtain up-do-date information. According to our results, a strong majority of multiple phar608 JAPhA | 5 3:6 | NOV/DEC 2013
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macy users were using only two pharmacies, implying limited fragmentation of medication information. However, as the prevalence of MPU increased in 2008 and 2009, the prevalence of multiple pharmacy users using more than two pharmacies also increased. Our study is the first to examine this aspect of multiple pharmacy use, and the trend in our results has important implications for pharmacists and should continue to be monitored. It will continue to be important for pharmacists to work with patients to identify other pharmacies that are used to obtain prescription medications. Examining the different types of pharmacies used by multiple pharmacy users is important, as it suggests the frequency of using pharmacies that potentially were electronically linked and thus may allow pharmacists to share patient medication information electronically across practice settings. For example, if a multiple pharmacy user is using two pharmacy types, an HMO/ clinic/hospital pharmacy and a community pharmacy (e.g., a Walgreens), these pharmacy types likely do not share medication profiles with one another. In addition, even if a multiple pharmacy user is using two community pharmacies, the pharmacies may (e.g., if they both are Walgreens) or may not (e.g., if one pharmacy is a Walgreens and the other is a CVS) share information. Our results across the study years showed that of multiple pharmacy users using only two pharmacies, roughly one-half were using a pair of pharmacies of the same type. Among multiple pharmacy users using more than two pharmacies, approximately 30% were using pharmacies of the same type. Taken together, less than one-half of all multiple pharmacy users were using pharmacies that had the potential to share information electronically. Given the variety of pharmacy ownership models within each pharmacy type category, the actual proportion of multiple pharmacy users using pharmacies that potentially are linked electronically was much lower. Strategies exist to help reduce unnecessary MPU at both the pharmacist and health system levels. Pharmacists can warn their patients of the potential risks of using multiple pharmacies and encourage them to consolidate their medications to one pharmacy or to the fewest number of pharmacies possible (e.g., one mail service pharmacy and one community pharmacy). In addition, pharmacists can ask patients to bring printouts listing all prescription and over-the-counter medications they currently are taking to each pharmacy visit. Pharmacists can then use the printouts to check for drug interactions against patients’ complete medication profiles. At the health system level, the use of electronic medication records (EMRs) that span across pharmacy organizations may be one way to ensure pharmacists are working with more complete patient medication profiles. Statewide prescription drug monitoring programs are examples of such initiatives; they have been estabJournal of the American Pharmacists Association
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lished in many states to improve patient care and safety and to reduce the abuse and diversion of prescription drugs. These programs contain information submitted to them by pharmacies and practitioners about monitored prescription drugs dispensed to patients in each state and provide pharmacists a more complete record of the use of these medications by patients. Other initiatives exist to share medical data among physicians and hospitals located in the same region across different organizations (e.g., when a patient is admitted to an emergency department). However, this may not be a complete fix, as any medications filled at pharmacies outside a shared EMR network still would be omitted from patients’ medication profiles. Given the nature of the MEPS data, identifying the pharmacy types that are under the same ownership or within the same health system is not possible. At a minimum, we can conclude that for a majority of multiple pharmacy users, pharmacists likely have to contact at least one additional pharmacy to obtain medication profile information. With the increasing trend of using more than two pharmacies, the burden of MPU on pharmacists likely is growing. Future research could explore the prevalence of multiple pharmacy users using pharmacies that have the ability to share information electronically by using, for example, prescription claims data that identify the name of the dispensing pharmacy. In addition, research could study the actual burden of MPU for pharmacists and explore the expansion of pharmacist access to electronic medical records and whether and how EMRs reduce the burden of MPU on pharmacists.
Limitations Our study had several limitations. First, we restricted our sample to respondents who had the opportunity to use multiple pharmacies (i.e., who had two or more prescription dispensations), whereas previous research has not made this distinction. A post hoc sensitivity analysis showed that this restriction resulted in a 3% to 4% higher rate of MPU than if all respondents were included. Second, the values for the type of pharmacy variables are determined solely by the household respondent and how they view the pharmacy establishment, with no definitions of the categories provided to the household respondents by MEPS interviewers (M.N. Stagnitti, personal e-mail communication, April 2010). Verification of these variables is not performed by MEPS personnel, resulting in general categories that do not provide details on the pharmacy locations (i.e., unable to divide community pharmacies into chain and independent pharmacies). Third, given the structure of the MEPS PM file, linking a specific medication fill with a particular pharmacy is not possible, which precludes analyses of the patterns Journal of the American Pharmacists Association
of MPU. Individuals may choose to patronize one main pharmacy while infrequently using additional pharmacies, for example, in an emergency, for an acute illness, or while traveling. These individuals may differ considerably in terms of health behaviors and outcomes from a person who uses multiple pharmacies on a consistent basis (e.g., individuals who routinely transfer their prescriptions to take advantage of coupons or promotions).
Conclusion The use of multiple pharmacies on a national level is common, and it increased between 2003 and 2009. These results have important implications for pharmacists and other health care providers, as they reinforce the fragmented nature of the medication use process. Although a majority of multiple pharmacy users used only two pharmacies, an increasing trend occurred in the use of three or more pharmacies. Further, our results examining the types of pharmacies used by multiple pharmacy users suggested that a majority of MPU occurred at pharmacies where medication profiles were likely not linked electronically. The results suggest that MPU may be requiring additional work for pharmacists to ensure complete and safe medication dispensing. Future research will further explore MPU and its relationship to patient characteristics and health outcomes. References 1. Shih A, Davis K, Schoenbaum S, et al. Organizing the U.S. health care delivery system for high performance. www.commonwealthfund.org/ Publications/Fund-Reports/2008/Aug/Organizing-the-U-S--HealthCare-Delivery-System-for-High-Performance.aspx. Accessed February 15, 2013. 2. Elhauge E. The fragmentation of U.S. health care: causes and solutions. New York: Oxford University Press; 2010. 3. Pham HH, Schrag D, O’Malley AS, et al. Care patterns in Medicare and their implications for pay for performance. N Engl J Med. 2007;356(11):1130–9. 4. Xu KT. Choice of and overall satisfaction with pharmacies among a community-dwelling elderly population. Med Care. 2002;40(12):1283–93. 5. McCombs JS, Nichol MB, Sclar DA. Single-pharmacy patronage and adverse drug reactions: a case study of cimetidine. J Res Pharmaceut Econ. 1993;5(1):3–24. 6. Gupta S, Rappaport HM, Bennett LT. Inappropriate drug prescribing and related outcomes for elderly Medicaid beneficiaries residing in nursing homes. Clin Ther. 1996;18(1):183–96. 7. Tamblyn RM, McLeod PJ, Abrahamowicz M, Laprise R. Do too many cooks spoil the broth? Multiple physician involvement in medical management of elderly patients and potentially inappropriate drug combinations. CMAJ. 1996;154(8):1177–84. 8. Kabat HF. Choice of source of pharmaceutical service. J Am Pharm Assoc. 1969;9(2):73–5. 9. Wu C, Bell CM, Wodchis WP. Incidence and economic burden of adverse drug reactions among elderly patients in Ontario emergency departments: a retrospective study. Drug Saf. 2012;35(9):769–81.
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610 JAPhA | 5 3:6 | NOV/DEC 2013
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