Prescription Medication Sharing: A Systematic Review of the Literature

Kebede A. Beyene, MSc; Janie Sheridan, PhD; Trudi Aspden, PhD

Disclosures

Am J Public Health. 2014;104(4):e15-e26. 

In This Article

Results

Our initial database search yielded 615 articles. The advanced Google search identified 56 articles, only 1 of which was not identified by the initial database search. We identified 16 additional articles by scanning the reference lists of articles retained for eligibility testing. Combining the results of all searches and removing duplicates yielded 514 articles. We discarded 81 because they were short communications on Web sites or were written by unspecified authors (i.e., they were not journal articles and did not have an author, casting doubt on their reliability). We read the title, abstract, or full text of the remaining 433 articles and retained 41 for further eligibility tests. We evaluated the retained articles according to our predefined inclusion and exclusion criteria and excluded 22 (Figure 1 shows detailed reasons). We performed our final qualitative synthesis on the remaining 19 articles.

Overview

A summary of the characteristics of the studies is presented in Table 2. The review comprised 19 studies with 36 182 participants from 9 countries. Eight of the studies were conducted in the United States, 4 in Australia, 2 in New Zealand, and 1 each in Canada, Nigeria, Malaysia, Qatar, and Ireland. The studies were conducted between 1990 and 2011, and the majority (73.7%; 14/19) were published between 2006 and 2011. The articles were published in 18 different journals. We retrieved 1 article from a conference proceeding.[25] The majority of the studies (73.7%; 14/19) used a quantitative, cross-sectional survey design, 21.1% (4/19) conducted qualitative interviews, and 5.3% (1/19) had a mixed-method design. The study participants ranged from children to older people. Three surveys investigated medication sharing among college students,[26–28] and 1 study focused on women of reproductive age.[23] Two studies reported on medication sharing among children and adolescents.[1,24] Of the 4 qualitative studies,[18,21,33,34] 3 assessed the experiences and attitudes of health workers about medication sharing; respondents worked in rural areas or with indigenous people.[18,21,33] Five studies focused on the sharing practices of older people;[17,19,20,29,31] 1 of these employed a mixed-methods research design.[31] The remaining 4 studies investigated medication sharing among adults with various sociodemographic characteristics.[22,25,30,32]

Of the studies that reported quantitative data (n = 15), 12 had sample sizes greater than 200 participants; only 7 studies explicitly stated that they recruited participants through random sampling.[1,17,23,26,28,29,32] Eight studies reported a participant response rate,[1,19,23,26,28,30–32] and 6 of these reported rates of 65% or higher.[19,23,26,28,30.31]

Medication Sharing

We found no reported gold standard method for measuring medication sharing. However, 2 of the surveys analyzed data collected in the US Healthstyles surveys,[1,23] and 5 studies adapted a question matrix used in these surveys to suit their own study.[22,24,25,28,31] The Healthstyles surveys asked respondents 2 separate questions to assess their lending and borrowing practices, respectively: "Have you ever shared your prescription medication with others?" and "Have you ever borrowed prescription medication from others?" For instance, in their analysis of 2001 to 2006 Healthstyles survey data, Petersen et al. considered respondents who responded positively to the first question to have lent medicines and those who responded positively to the second question to have borrowed medications;[23] they considered those who responded negatively to one of the questions and do not know–not sure to the other not to have lent or borrowed medicines.

Because self-reported survey studies used various recall periods, we could not calculate the average prevalence rate of all studies. However, prevalence rates varied across the studies (Table 3). For medication borrowing, the reported rate was between 5% and 51.9%, and for lending, between 6% and 22.9%. The lowest rates for both borrowing and lending were reported in a survey among older people,[31] and the maximum rates came from 2 separate surveys, of Nigerian university students[28] and US adult participants.[22] Of 10 studies that reported both lending and borrowing rates,[1,17,19,22–25,27,28,31] the majority (n = 6) reported rates higher than 16%.[23–25,27,28,34] Eight studies reported the prevalence rate of lending or borrowing, which ranged from 5% to 54.3%.[1,20,22,23,26–29] Of these, 5 reported a rate higher than 27%.[22,23,26–28]

Four studies reported that medication lending was more common among female than male participants;[1,17,22,23] however, in 2 other studies lending behavior was not significantly associated with gender.[24,28] Two studies found no gender difference in the rate of borrowing.[22,23] Medication sharing was also associated with age,[23,26,28] and those aged 18 to 24 years were more likely to report medicine sharing.[23,26] For medication borrowing, a study reported a higher rate among women of reproductive age (18–44 years) than among older women (≥ 45 years).[23] Findings about medication lending were not consistent across studies. For example, Petersen et al. documented a higher rate of lending among reproductive-aged than older women,[23] but Goldsworthy and Mayhorn did not find age to be a significant predictor of medication lending.[24]

In 4 studies, race/ethnicity was associated with medication sharing.[22–24,26] Ali et al. reported a higher rate of sharing among participants of Malay ethnic origin and Chinese college students;[26] however, they did not report the comparison group. Another study documented higher odds of sharing among US non-Hispanic White reproductive-aged women than among women who were Hispanic or whose race/ethnicity was not White, Black, or Hispanic.[23] However, in 3 other studies race or ethnicity was not associated with either lending or borrowing.[25,29,30] Thirteen of the surveys in our review did not assess the association between income and medication sharing.[17,19,20,22,24–32] However, in a study among US children and adolescents (aged 9–18 years), lower income was associated with sharing prescription medicines with family members or friends (P < .01).[1] Many of the reviewed studies did not explore or report the influence of the Internet on medication sharing. Petersen et al. noted that those who accessed health information from the Internet were more likely than those who did not to report medication sharing (relative risk = 1.50; 95% confidence interval = 1.44, 1.56).[23]

Daniel et al.[1] and Petersen et al.[23] found that a larger household size was a positive predictor of medication sharing. A study that assessed the use of nonprescribed medications for pain management among veterans found substance use disorders (P = .006) and pain interference activities (P = .047) to be positive predictors of sharing.[29]

A study among adults visiting an urban medical center in the United States reported less likelihood of medication borrowing among participants with Medicare insurance (P = .03) or a primary health care provider who frequently asked about medication usage (P = .049).[30] Petersen et al. reported less likelihood of lending or borrowing among reproductive-aged women who used a multivitamin daily (relative risk = 1.28; 95% confidence interval = 1.18, 1.40).[23]

Commonly Shared Prescription Medicines

Study participants reported sharing a wide range of prescription medicines. Twelve of the 15 surveys reported the types of medicines shared.[17,19,20,22–25,27,28,30–32] Seven of the surveys used a predetermined list of medications and asked participants to indicate the medications they shared from the list.[1,22–25,28,31] The qualitative studies mainly explored the reasons behind prescription medicine sharing and did not report the specific types of shared medicines.

A study of US adults that involved one-on-one interviews found allergy medications, pain medications, and antibiotics to be the most commonly shared medication classes.[22] Acne medications were also found to be widely shared.[17,22–24] Petersen et al. reported a high rate of isotretinoin sharing (25%) among women of child-bearing age.[23] Four studies documented sharing of birth control pills among women.[22–24,27] Hogan et al. reported the sharing of prescription topical corticosteroids and other dermatologic medications among randomly selected dermatology outpatients.[17] Sharing of antibiotics among the general adult population was also common.[17,22–24,27,28,30–32] In addition, studies reported sharing of antidiabetic, cardiovascular, and antihypertensive medications.[19,20,22,30–32]

Seven surveys gave respondents a predetermined list of reasons and asked them to indicate those that influenced them to share their medicines.[1,19,22,23,28,30,31] In 4 of these studies, respondents received an additional list of hypothetical scenarios to assess situations in which they would be willing to share.[1,22,23,31] In 3 studies, the main situation in which borrowing occurred involved a person already taking a medicine but running out of it or having the same medical problem as the person who had the medicine.[22,23,31] Participants also expressed their willingness to borrow medications if they were obtaining the medicines from a family member or a friend,[1,30] if the medicine was unaffordable,[31] if the situation was an emergency,[1,22] if they obtained a lot information about the medicine from advertisements and commercials,[23,28] for convenience,[30] or for pain management.[1] The primary explanations for lending behavior were having leftover medication[22,23] and the desire to help others.[22] Respondents were also willing to lend their medicines if asked by a family member or friend or by a person with a similar problem or taking similar medicine and or in emergency circumstances.[19,22]

Consequences of Medication Sharing

Although the surveys in our review focused on investigating the adverse consequences of sharing, the qualitative studies reported both benefits and adverse consequences. Kamutingondo et al., in a qualitative study among 4 Zimbabwean households in New Zealand, noted that sharing medicines during illness is a means of expressing a caring relationship among family members in a time of sickness.[34] Hodgetts et al., in a focus group discussion with 7 Māori health workers in New Zealand, reported that sharing is a convenient means of accessing prescription medicines among Māori.[33] Moreover, the research team revealed a process of accessing medications on behalf of others by the use of proxy symptoms (i.e., pretending they were ill to obtain prescriptions from general practitioners) among members of a whānau (an extended family group that may span 3–4 generations). Anglin and White documented that sharing was a means of accessing prescription medicines in a rural eastern Kentucky neighborhood largely populated by poor and unemployed people.[18]

In a study among 594 adolescents recruited from 11 cities,[24] which was part of a larger survey (n = 2773) designed to investigate medication sharing in the United States,[25] among respondents who borrowed medicines (n = 115), 37.4% had experienced a side effect or an allergic reaction and only about half reported receiving either verbal (55.6%) or written (47.8%) instructions from the person lending the medicine. Moreover, 75% (n = 86) of the borrowers were trying to avoid a medical visit; however, 26.7% (23/86) of these ended up visiting health care providers after their effort to self-medicate with borrowed medicines failed, and one third (28/86) did not inform their health care providers during their next medical visit about the medications they borrowed.

Recommended Interventions

The studies suggested various interventions to reduce the harms and risks of sharing medications. Daniel et al.[1] noted that sharing behaviors might be formulated early in the life course, during childhood or adolescence, and they suggested providing targeted messages about the safe use of prescription medications to parents and their children. Authors also recommended providing health messages on the risks of sharing.[23,24,30] These included alerting women to the dangers of sharing teratogenic medications,[23] regular cautioning of patients about risks of inappropriate medication usage,[30] and adding messages that prohibit sharing in product packaging.[24] Researchers also recommended informing patients about appropriate disposal practices for leftover medications[27] and reexamining the cost of health care access, particularly for low-income persons.[33] Recommended strategies to increase access were reconsidering physicians' fee structures and reducing prescription charges in pharmacies.[33]

Authors also suggested methods to identify medication borrowers and lenders. One suggested technique was inquiring about patients' medication usage during health care provision.[30] Even when patients deny borrowing or lending medications, researchers advocate cautioning them about the risks as a potentially effective deterrent.[30]

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