Review Article

IJPP 2009, 17: 79–88 ß 2009 The Authors Received November 7, 2007 Accepted January 6, 2009 DOI 10.1211/ijpp/17.02.0002 ISSN 0961-7671

Consumers’ views on generic medicines: a review of the literature Mohamed A.A. Hassali, Asrul A. Shafie, Shazia Jamshed, Mohamed I.M. Ibrahim and Ahmed Awaisu School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia

Abstract Objectives To review the literature on consumers’ knowledge, attitudes and opinions of the use of generic medicines. Method A narrative review of studies conducted from 1970 to 2008 on consumers’ perceptions and views towards generic medicines was performed. An extensive literature search was undertaken using indexing services available at the authors’ institution library. The following keywords were used for the search: brand, generic, multisource, medications, medicines, drugs, pharmaceuticals and consumers, customers, and patients. Electronic databases searched were Medline, Inside Web, ISI Web of Knowledge, Science Direct, Springer Link, JSTOR, Proquest, Ebsco Host and Google Scholar. These electronic databases were searched for full text papers published in English from 1970 to October 2008. Key findings Twenty studies were identified. Eleven were from the USA, four were from Europe, two were from Canada and one each was from Australia, Brazil and Malaysia. In general, consumers showed mixed reactions towards the use of generic medicines. This was evident from the divergence of views observed by country development level, consumers’ socioeconomic characteristics, drug product characteristics, pharmaceutical reimbursement system, policy environment, contact with health care professionals, past experience with medications, and knowledge of the seriousness of a medical condition. Conclusions Patient confidence and knowledge pertaining to generic medicines use have increased over the past four decades, especially in developed countries. Mass educational efforts, financial incentives, and greater communication among patients and health care professionals were seen as major drivers to the uptake of generic medicines among consumers. Keywords consumer; generic medicines; knowledge; perceptions; policy

Introduction

Correspondence: Mohamed Azmi Ahmad Hassali, Senior Lecturer, Discipline of Social and Administrative Pharmacy, School of Pharmaceutical Science, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia. E-mail: [email protected]; [email protected]

Timely and effective use of medicines can ensure effective treatment of many illnesses and avoid or delay the need for costly hospital treatment for patients. Significantly, generic medicines can effectively treat many of today’s illnesses and their use provides the opportunity to substantially reduce costs to health care budgets and patients.[1–3] There is no doubt that branded medicines have exercised tremendous influence in medicines utilization, but generic drugs, being bioequivalent to their brand-name counterparts, are considered safe as well as cost-effective.[4] Globally, the use of generic drugs has increased steadily as a result of economic pressures on drug budgets. In this review, consumer refers to a person who buys medicinal products for either personal use or the treatment of a disease. Generic medicines provide the opportunity for major savings in health care expenditure directly to the consumers as well as to the government, given that they are generally lower in price than their brand-name equivalents.[5–7] Savings made by using generic medicines for established therapeutic care would provide leeway for health care systems and patients to finance the purchase of the generally more expensive, innovative products required to treat illnesses that at present lack adequate pharmaceutical treatment.[8,9] In the debate over the use of branded versus generic medicines, consumers’ perceptions based on their concerns regarding the risks involved and on their beliefs concerning the use of generic drug products have been neglected.[10]

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In this article we provide a chronological review of the literature on consumer and patient knowledge, attitudes and opinions about the use of generic medications. This study provides the views of consumers from various settings in a narrative way. The review also offers several recommendations that health care professionals can implement in their practice settings to improve their patients’ utilization of generic medicines.

Methods A literature search was performed from May to October 2008 to identify published studies related to the views of consumers or patients on generic medicines. In this narrative review, only studies which measured consumers’ views and perceptions towards generic medicines were included. Studies that utilized either qualitative or quantitative approaches, or both, were included in the review. However, we excluded quantitative survey studies with fewer than 50 respondents as their sample. The retrieved literature was abstracted using a standardized data-abstraction form in a table format containing most of the elements presented in Table 1 and our selection criteria. Each study was reviewed by all five authors and a consensus meeting was convened to ensure quality assurance. The search strategy involved using Boolean operators for combinations of the following terms: brand, generic, multisource and medications, medicines, medications, drugs, pharmaceuticals and consumers, customers, patients. Equivalent terms in thesauruses or Medical Subject Heading (MeSH) browsers were used whenever possible. The search was limited to full paper articles published in English between 1970 and October 2008. However, our search was not limited to prescription-only medicines, but also covered studies involving consumers’ perceptions of non-prescription medicines. Electronic databases searched included Medline, Inside Web, ISI Web of Knowledge, Science Direct, Springer Link, JSTOR, Proquest, Ebsco Host and Google Scholar. These searches were supplemented by a hand search of the reference lists in the reports identified. To determine whether or not reports met the required criteria, the lists of titles and abstracts from the searches were examined and where doubt remained, the whole paper was examined. Reports that were identified were arranged chronologically starting from the 1970s and ending in the 2000s.

Results Three hundred and eighty two titles and abstracts were identified by three authors from electronic searches of the nine databases and, wherever possible, a review of the reference lists. Of these, 313 titles and abstracts not related to consumers’ views on generic drugs and duplicated citations were examined and excluded. The full text of 69 articles was retrieved and distributed among the five authors for further assessment. All authors agreed that 41 of the 69 manuscripts did not really assess consumers’ or patients’ knowledge of and views towards generic medicines and therefore were not suitable for inclusion in the review. The majority of these were largely looking at the clinical effectiveness of generic

medicines or other clinical perspectives. Thus, 28 studies were potentially appropriate for possible inclusion in the review. However, eight observational quantitative studies with a relatively small sample size (less than 50) were also eliminated. In the final review, 20 studies which satisfied the selection criteria were included in the analysis. The quorum flow chart for this review is shown in Figure 1. Here we provide a narrative review of the studies conducted during the last four decades in a chronological order.

The 1970s Early studies on generic drugs examined attitudes, perceptions of risk and knowledge of and satisfaction with generic medications, and compared the views of consumers, physicians and pharmacists. Most of these studies were conducted in the United States. The first study retrieved and included in the review was by Lambert et al.[11] This study was done in Florida to assess the predisposition of 510 consumers to acceptance of generic drugs. In this study, it was observed that approximately 66% of the respondents rejected lower-cost generic alternatives, regardless of the amount of savings suggested. Those rejecting generic drugs were older and had higher incomes, and they perceived generic medicines as less effective than did those accepting the drugs. The researchers examined the effect of 18 variables on the predisposition towards generic drugs and found only two variables to have significant effect. The first was age, which showed that older respondents were more reluctant to switch to generic alternatives. The second was perceptions of effectiveness, with rejecters perceiving low-priced drugs to be less effective in relieving an illness. Bearden and Mason,[10] in a study published in 1978, surveyed 105 consumers regarding their attitudes towards the risks involved with the use of generic medications. As a framework for this study, the investigators used Fishbein and Ajzen’s theory of reasoned action, which postulated that an individual’s attitude towards an action is based on the summation of his or her beliefs about the consequences or risks of the behaviour and weighted by the perceived value of these consequences. Risks were represented by the probability and importance of loss across six dimensions: financial, social, drug performance, psychological, physical and convenience. The investigators examined consumers’ beliefs about and evaluations of the quality, price, safety, adverse effects and efficacy of generic medications, as well as the reputations of generic drug manufacturers. Approximately one-third of the consumers surveyed were negatively inclined towards the use of generic drugs, one-third were positively inclined and the remainder were neutral. Those opposed to generic substitution perceived higher risk levels for each of the six dimensions and considered those risks to be more important than did those favouring generic substitution practices. The latter believed that generic drug products were high in quality, safe and produced by reputable manufacturers, and that they would have the intended results. Further analyses indicated that consumer preferences (negative, positive and neutral) regarding the purchase of generic drugs were influenced by their concerns about drug performance, potential financial loss and safety.

Questionnaire survey

Interview-administered survey Questionnaire survey

Questionnaire survey

Field experiment using prescription analysis Questionnaire survey

USA

USA

USA

USA

Canada

Mason and Bearden 1980[12]

Bearden and Mason 1978[10] Shepherd 1988 [13] Tootelian et al. 1988[14]

Podulka et al. 1989[15]

Kendall et al. 1991 [16]

USA

USA

USA

USA

Rosendahl 1994[17]

Muirhead 1994[18]

Ganther and Kreling 1995[19]

Momani et al. 2000[20]

USA

Questionnaire survey

USA

Lambert et al. 1980[11]

Mailed questionnaire survey

Mailed questionnaire survey

Mailed questionnaire survey

Questionnaire survey

Method

Country

Study

Household

Household

Nation-wide survey

Communitybased

Chain drug store

Communitybased

Community pharmacies College

Household

Household

Household

Setting

303

355

876

736

295

100

389

621

105

105

510

Number of participants

Outcomes

Limitations highlighted

Frequent purchasers perceived generics as high quality, safe and effective. Brand drugs were viewed as being more effective, having less potential for adverse effects and providing greater value than their generic counterparts. The greater the perceived risk of the prescription drug, the greater the respondent’s inclination to view the brand medication more favourably. Generic drugs were seen as equal in quality to their brand-name counterparts. Consumers felt confident if a physician or a pharmacist recommended a generic drug. People were less likely to take them for chronic and serious conditions. Perceptions of the illness was the influential variable in consumer attitudes, not the perception of generic products. 80% of the patients accepted the offered generic substitute prescription drug. Older patients were less likely to accept a substitute. 33% aged 45–65 years asked their physician and pharmacist for a generic medication. 29% aged 65 and older requested a generic drug from the physician/pharmacist. 29% considered generic drugs to be ‘equal’ in quality to branded products. 45% considered the two types of drug to be ‘about the same’. Lower-income patients viewed generic drugs as being lower in quality. Perceptions of risks depended on the medical condition. 54% perceived generic prescription drugs to be riskiest in heart ailments. 14% perceived generic prescription drugs to be least risky in streptococcal throat infections. Financial incentives were important to the increased use of generic products. The patient’s health plan mandated generic substitution in 51% of cases. Overall attitude towards generic substitution was somewhat positive.

(Continued)

Generalization was not possible as the study was conducted in three states only.

Limitations not mentioned by authors.

Limitations not mentioned by authors.

Limitations not mentioned by authors.

Limitations not mentioned by authors..

Limitations not mentioned by authors.

Limitations not mentioned by authors.

Limitations not mentioned by authors.

Only two variables, i.e. age and perceptions of effectiveness, have Findings were based on expressed significant effects on the predisposition towards generics. intentions and not the actual purchase behaviour. One-third of the consumers were negatively inclined toward the Generalizability was limited as use of generic drugs; one-third were positively inclined probability sampling was not (remainder were neutral). employed. Consumer’ preferences about purchase influenced by their concerns about drug performance, potential financial loss and safety. Overall consumers seemed supportive of generic prescribing and Generalizability was limited due substitution because they believed savings will result to them. to lack of probability sampling.

Table 1 A summary of the studies included in the review investigating consumers’ perception of generic drugs

Semi-structured interviewadministered survey Self-administered questionnaire survey

Australia

Canada

Norway

Finland

Portugal

USA

Malaysia

Hassali et al. 2005[23]

Pereira et al. 2005[24]

Kjoenniksen et al. 2006[25]

Heikkila et al. 2007[26]

Figueiras et al. 2007[27]

Iosifescu et al. 2008[28]

Al-Gedadi et al. 2008[29] Questionnaire survey

Interviewadministered survey

Questionnaire survey

Questionnaire survey

Mailed questionnaire survey

Structured interviewadministered survey

Brazil

Bertoldi et al. 2005[22]

A prospective randomized multi-centre (intervention) study

Method

Spain

Country

Valles et al. 2003[21]

Study

Table 1 (Continued)

Annual university open day

Tertiary care hospital

Public places

Community pharmacies

Household

Clinic

Household

Household

27 Public primary care centres

Setting

99% agreed to receive a generic formulation. Individual educational intervention with repeat prescribing resulted in a high rate of generic acceptability.

Outcomes

400

28% 64% 32% 34%

The study is not representative of the whole Portuguese population as it only covered urban residents.

Sample disparity in two geographical locations as well as the response rate of less than 50% in both geographical locations were indicative of weak methodology.

Limitations not mentioned by authors.

Limitations not mentioned by authors.

Limitations not mentioned by authors.

A low number of patients refused to change brand-name drugs to generic drugs. Duration of the study (12 months) and the relatively low percentage of generic drugs prescribed were limitations. Limitations not mentioned by authors.

Limitations highlighted

Generalizability was limited due to low recruitment rate and use of a single institution. were familiar with the term generic medicine. Generalizability was limited due to understood that generic drugs cost less to branded ones. small sample size and non-probability thought generic drugs may cause more side effects. sampling technique that may have had received information on generic drugs from pharmacists. caused response bias.

86% showed understanding that generic drugs cost less. 70% showed understanding that the quality is similar to brand-name medicines. 57% showed understanding about packaging characteristics. Important determinants in choosing medicines were price and the prescribed drug in the medical prescription. 16 There was a positive attitude towards generic drugs. Barriers to acceptance were influence from medical practitioners, side effects and confusion with different brands. 81 40% agreed that all generic products that Health Canada deems bioequivalent could be used interchangeably with their brand-name versions. Patients primarily had neutral views on generic warfarin, although a minority had concerns regarding generic warfarin substitution. 386 41% of patients did not allow substitution to generic medicine. Two-thirds of those who had used them were satisfied with generic medicines and one-third of patients who switched had negative experiences. 547 Respondents Generic substitution was a successful reform measure. who refused The most important reason for refusing substitution was satisfaction with medicines used previously. generics; 213 respondents who accepted generics 1125 There were well-defined beliefs about generic drugs concerning their efficacy and similarity with branded drugs. Age and level of education had significant effects on beliefs about efficacy. 311 Older adults with low income and low health literacy mistrusted generic drugs.

19 Centres (control group); 8 centres with 4620 subjects (intervention group) 3182

Number of participants

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Titles and abstracts identified by electronic search of all nine databases and, wherever possible, review of the reference lists (n = 382)

Titles and abstracts not related to consumer views on generic medicines and duplications (n = 313)

Full text of articles retrieved for further assessment (n = 69) Papers not really assessing patient/consumer views on generic drugs, but rather largely looking at the clinical effectiveness of generic medicines in patient populations (n = 41)

Potentially appropriate studies for possible inclusion in the review (n = 28)

Observational quantitative studies with a sample size of less than 50 were excluded from the review (n = 8)

Studies related to consumers’ perceptions of generic drugs, and which satisfied the selection criteria, were included in the review (n = 20) Figure 1 Quorum flow chart of the review process.

The 1980s To supplement the findings from their previous research,[10] Mason and Bearden conducted another study to explore salient issues affecting prescribing, dispensing and use of generic medicine.[12] Consumers did not feel that they would face greater risks if prescribing generic drugs became a practice. Although neutral on generic substitution practices by pharmacists, they believed that prescribing generics would maintain a steady and continued supply of drugs. They endorsed the idea that generic drugs would produce the intended therapeutic effects, but showed hesitancy in utilizing drugs produced by unknown manufacturers and agreed that the high prices of branded drugs were due to high expenditure on advertising to encourage physicians to prescribe brand-name products. Overall, consumers seemed supportive of generic drug prescribing and substitution because they believed this would result in them saving money. The authors concluded by emphasizing the role of educating physicians early in their career about generic prescribing and the viable role other health professionals, such as pharmacists, can play in health care.

In a 1988 study involving 621 consumers in Austin and San Antonio, Texas, USA, 33% of those interviewed had never purchased generic prescription medications.[13] Consumers felt that, compared with branded drugs, generic drugs were of lower quality, more risky, less effective and less healthful. Yet, contrary to findings from previous studies, individuals older than age 55 years thought that generic drugs were of higher quality than did younger respondents. A study conducted by Tootelian et al. in 1988,[14] which focused on 389 college students and their perceptions of eight types of prescription medication, found that branded drugs were viewed as being more effective, having less potential for adverse effects and providing greater value than their generic counterparts. The greater the perceived risk of the prescription drug, the greater the respondent’s inclination to view the brand medication more favourably. Age may have influenced the views of this group, since more than 85% of individuals in the sample were 30 years or younger. Furthermore, in a study of 100 consumers in the Chicago area, published in 1989, the majority of consumers replied that generic medications were equal in quality to their brand-name

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counterparts.[15] Almost all the consumers surveyed said they would feel confident about a generic drug if a physician or a pharmacist recommended it. Although consumers knew what generic drugs were, had positive experiences with them and thought they were equal in quality to brand-name products, they were less likely to take them for chronic and serious conditions. The authors concluded that the influential variable in consumers’ attitude towards generic drugs may have been their perception of their illnesses and not that of the generic products. The factors that influence generic substitution, satisfaction and intention to purchase generic drugs surfaced again in a field experiment involving 295 patients who had obtained prescriptions for one of two brand-name products at one chain pharmacy in Vancouver, British Columbia, Canada.[16] More than 80% of the patients offered a generic substitute for one of the study drugs accepted it. Patients who were older, less educated and had prescription drug coverage were less likely to accept a substitute. Satisfaction with generic drugs was lowest for those who had no choice in their use and did not have to pay anything to receive the medication. Intention to purchase another generic drug product in the future was influenced by having recently accepted a generic substitute, perceiving that the cost savings would be high and having to pay some or all of the cost of the medication. As did previous authors, Kendall et al. concluded that having pharmacists actively promote generic drugs and having patients pay some part of the cost of the medication would increase the rate of generic substitution.

The 1990s A study conducted by the American Association of Retired Persons (AARP) and published in 1994 found that more than 84% of consumers were familiar with the term generic drug.[17] The author of the study estimated that approximately 33% of Americans aged 45–65 years had asked their physician for a generic medication and asked their pharmacist to fill a prescription with a generic medication. However, a slightly lower proportion (29%) of those aged 65 and older were likely to request a generic version of a drug from their physician or pharmacist. In 1994, a survey by Muirhead[18] examined how 876 consumers across the USA viewed managed care and generic medications. Approximately 40% of respondents reported that they were likely to request generic substitution. The findings indicated that 34% of pharmacists and 36% of physicians had initiated generic substitution on consumers’ behalf. Generic products were considered ‘equal’ in quality to brand-name products by 29% of consumers, and 45% indicated that the two were ‘about the same’. Patients with lower incomes were more likely than higher-income individuals to view generic drugs as lower in quality. A study of consumers conducted in 1995 but published in 2000[19] rekindled the concept of risk with the use of generic medicines. Ganther and Kreling[19] surveyed 355 adults in central Wisconsin, USA, and found that consumers’ perceptions of the risks of generic prescription drugs depended on the medical condition being treated. Study participants were asked to assess the comparative risk associated with purchasing a generic drug instead of a brand product for

heart problems, high blood pressure, streptococcal throat infection, pain and cough. Respondents thought that substituting generic prescription drugs was riskiest when treating heart problems (54%) and least risky when treating streptococcal throat infection (14%). Respondents also indicated the amount of savings they would require before they would accept a generic version of a drug instead of the branded product. As the risk rating for the medical condition decreased, more respondents were willing to take the generic product for less than a US$2 cost saving. As the risk rating increased, so did the percentage who wanted a cost savings of more than $15 before they would buy the generic drug or who would not buy the generic product at any cost saving. The authors concluded that financial incentives might be important to increasing consumers’ use of generic products. Similar to authors of previous studies, Ganther and Kreling[19] identified patient education by the pharmacist as another important factor in increasing generic drug use for medical conditions perceived by patients as high risk.

The 2000s Momani et al.,[20] in a study published in 2000, investigated consumer awareness of drug-management strategies (formularies, drug co-payments, prior authorization and generic substitution). This mail survey was sent to 303 members of managed care organizations in Maryland, Pennsylvania and West Virginia, USA. Approximately 51% of the respondents indicated that their health plan mandated generic substitution. Consumers agreed that generic substitution affected their compliance with medications. In addition, consumers were neutral in regard to the following statements: ‘generic substitution makes it more convenient to get my medicines’ and ‘generic substitution limits my chances to get the best medicine’. Consumers agreed mildly with the statements ‘generic substitution results in less effective medicines’ and ‘generic substitutions compromises the quality of my medicines’. Although these statements reflected a slightly negative view towards generic substitution, when consumers were asked a general question regarding their overall attitude towards generic substitution, a somewhat positive response was obtained (mean ± SD = 4.6 ± 1.99 on a seven-point scale where 1 is negative and 7 is positive). The authors concluded that, overall, this group of consumers held a slightly positive attitude towards generic drugs and were most aware of generic substitution and drug co-payments as means to manage drug costs. In Spain, where the implementation of drug patent legislation was introduced in late 1997 and generic drugs shared only 0.15% of the Spanish drug market, Valles et al.[21] assessed patients’ acceptance of the substitution of brand-name drugs for generic drugs for chronic conditions in primary health care practices. A prospective randomized multicentre study was conducted over a 12-month period in which patients taking medications for chronic disorders received an educational intervention on generic drugs at the time they attended different general practices in the city of Barcelona for repeat prescribing. Twenty-seven public primary care centres were randomized to the intervention group (eight centres) or the control group (19 centres). Of 4620 patients in the intervention group who received verbal

Consumers’ views on generic medicines

information and handout materials on the advantages and disadvantages of generic equivalents and brand-name drugs, 98.9% agreed to receive a generic formulation. The primary care centre and the class of drug were associated with statistically significant differences in the percentage acceptance of generic drugs. In the overall population, generic prescribing in the intervention practices increased to 5.9% as compared with 2.8% in controls. Individual educational intervention in patients with repeat prescribing resulted in a high rate of generic acceptability. In the context of developing countries, only one study, which was conducted in Brazil, was retrieved.[22] In this study, the authors estimated the proportion of generic drug use from the total of medicines used, assessed the population’s knowledge of generic drug characteristics and studied the most common criteria used by consumers for purchasing medicines. A representative household sample was selected, making a final sample of 3182 individuals. Data were collected using a structured interview. Interviewees were asked about the utilization of any medicine in the previous 15 days and requested to show the packaging and prescription, and according to these packages drugs were classified as branded or generic. Population knowledge of generic drug characteristics were assessed by asking the following questions: (a) Does the generic drug cost more, the same or less than the brand-name drug? (b) Is the quality of generic drugs better, the same or worse than that of brand-name drugs? (c) What does the generic drug packaging contain that differentiates it from other drugs? Strategies for choosing preparations when purchasing a medical prescription were investigated for the last purchase in the previous 15 days, or the habitual strategy for interviewees who had not purchased medicines during that period. Interviewees were asked whether they (a) buy (or always buy) exactly the prescribed medicine, (b) replace (or usually replace) the prescribed drug with the corresponding generic one, (c) replace (or usually replace) the prescribed drug with a formulated product and (d) replace (or usually replace) the prescribed drug with a lower-priced alternative, regardless of whether it was a generic, formulated or similar drug. Findings showed that the proportion of generics in total medicines was 3.9%. While 86% knew that generic drugs cost less and 70% knew that the quality is similar to brand-name medicines, only 57% knew any packaging characteristics that distinguish generic medicines from other ones. The authors concluded that the most important determinants in choosing medicines are price and the medical prescription, as the majority of individuals reported buying exactly what was prescribed. In a recent Australian study,[23] the researchers used a qualitative approach to explore consumers’ perceptions and opinions of generic medicines and to identify barriers to their use of generic medicines. The researchers interviewed 16 consumers aged 22–80 years, living in the metropolitan area of Melbourne, Australia, and using thematic content analysis they identified four themes related to generic medicine utilization. These were: knowledge about generics, acceptance of generics, non-acceptance of generics and educational needs pertaining to generics. In this study, it was found that most patients were not familiar with the term generic medicine but they were more familiar with the term

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cheaper brand of medicine. The major reason for acceptance was cost, and the major barriers to acceptance were influence from medical practitioners, side effects from generic brands and confusion from using different brands. Finally, the authors concluded that consumers generally had positive attitudes towards the use of generic medicines and suggested that direct patient education by the health care providers on issues relating to safety and efficacy of generic medicines could further enhance their uptake. Since 2000, three generic brands of warfarin have been approved in Canada as bioequivalent to Coumadin“ (BristolMyers Squibb) and generic warfarin has been added to provincial drug formularies. In this context, Pereira et al.[24] investigated perceptions and attitudes towards usage and prescribing of generic alternatives to branded warfarin. Respondents were required to indicate their level of agreement on a scale of 1–7 (1 being ‘strongly disagree’ and 7 being ‘strongly agree’) to 10 statements regarding their perceptions of generic brands and, more specifically, the safety and efficacy of the generic brands of warfarin compared to brand-name warfarin. From 500 patients of an anticoagulation clinic, 81 responded to the surveys. Overall, respondents were familiar with generic brands and comfortable taking generic brands of drugs (42.5 and 46.9% respectively). Of all respondents, fewer than 5% agreed or strongly agreed that the lower cost of generic warfarin was a good reason to take it rather than brand-name warfarin. However, patients taking branded warfarin did not see that low price of generic warfarin is a good incentive for its use. Fourteen percent of respondents agreed or strongly agreed that generic warfarin was neither as safe nor as effective as brand-name warfarin. Additionally, 32.1% of respondents agreed or strongly agreed that they were aware that generic products such as warfarin must undergo bioequivalence testing with brand-name warfarin and the same percentage were satisfied that such testing ensured their safety. Patients taking brand-name warfarin were less likely to agree that generic warfarin products are as safe and as effective as brand-name warfarin. A large percentage of patients who completed the surveys indicated that they were unaware that generic drugs are tested as rigorously as brand-name warfarin. The authors concluded that the patients held neutral views on generic warfarin, although a minority had concerns regarding generic substitution, and an obvious lack of awareness of bioequivalence regulations as they pertain to warfarin. In Norway, new pharmacy legislation implemented in March 2001 allowed Norwegian pharmacies to switch the medication originally prescribed to a generic medicine. Pharmacists in Norway are obliged to inform the patient about the cheapest available generic drug according to a list produced by the Norwegian Medicines Agency. The patient and/or the doctor can refuse generic substitution, but the patient may as a result pay a higher price in some cases. Kjoenniksen et al. conducted a study in 2006[25] to assess patients’ attitudes towards and experiences of generic substitution 3 years after generic substitution of prescription medicines was permitted. A mailed questionnaire was sent to 404 patients receiving eight or more different drugs on the fifth level in the Anatomical Therapeutic Chemical (ATC)

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system, which yielded 386 usable responses. The study showed that a high percentage of patients (41%) did not allow their medicines to be substituted, two-thirds of the patients who had used generic medicines were satisfied, and about one-third of patients who switched had negative experiences. This confirms that generic drug substitution for a number of patients is not perceived as an equal alternative to branded drugs, and these patients may need additional information and support. Information about generic substitution strongly affected whether patients had switched or not, where a combined effort from doctors and pharmacy staff seemed to be the most effective, and this confirms that efforts to increase generic substitutions should be targeted first and foremost at health care practitioners. Generic substitution was introduced in Finland at the beginning of April 2003 with the aim of curbing the rise in the medical expenses of society and individuals. Pharmacists are obligated to substitute the cheapest or close to the cheapest medicine for prescribed medicine unless the customer refuses or the physician forbids substitution, which the physician can do for medical or therapeutic reasons. Heikkila et al.[26] conducted a descriptive study to explore the opinions, attitudes and experiences that physicians and customers had of this legislative reform. Customers’ views were explored using two questionnaires: the first questionnaires were handed out in 15 pharmacies in five geographical areas of Finland to customers (n = 544) who had refused generic substitution, and the second in 18 pharmacies in six geographical areas to customers (n = 214) who had accepted substituted medicines at least once. They found that the majority of customers thought generic substitution was a good reform measure, and the physicians had accepted it. Generic substitution was thought to be a good reform measure especially among customers who had accepted it and had experience with it. Customers who had refused substitution might have a negative prejudice or they were careful with this reform. The savings in medical expenses and the advice given by the pharmacists were the main reasons for accepting substitutes. The most important reason for refusing substitution was satisfaction with medicines used previously. Most of them thought cheaper medicines were as effective and safe as more expensive ones. The authors concluded that generic substitution had been a successful reform measure, but that some customers had been confused and cautious, at least in the early stage, because the situation was new to them. In 2007, Figueiras et al.[27] conducted a cross-sectional survey in Portugal to explore the influence of the common illnesses influenza, asthma and angina pectoris on the level of agreement with the prescription of generic medicines as well as to investigate the implication of socio-demographic factors on lay beliefs about generic medicines. The opportunistic sample (n = 1278) was recruited from the general population of Portugal over a 4-week period. A total of 101 questionnaires were incomplete and 52 people declined to participate, so the final sample was 1125 Portuguese (61% females; mean age 33 years), giving a response rate of 88%. Participants seemed to have had well-defined beliefs about generic drugs concerning their efficacy and similarity with brand medicines. Beliefs about

the efficacy of generic medicines differed significantly according to age group and level of education. Although participants exhibited a moderate level of agreement with the prescription of generic medicines for influenza, asthma and angina pectoris, their agreement decreased significantly when the illness was perceived as more serious. The overall results indicated that participants generally believed that generic medicines were effective and similar to their brand equivalents. The strongest beliefs in the efficacy of generic medicines were held by the more educated and younger participants, whereas the strongest beliefs in the similarity of generics to their branded equivalents were held by older participants. Iosifescu et al. published a study in 2008[28] about the beliefs of older adults regarding generic drugs and assessed potential correlates of these beliefs, including socioeconomic and health status variables, health literacy and physician communication skills. Adults more than 65 years of age (n = 311) were interviewed in two primary care practices of a tertiary care hospital. Beliefs about generic drugs were measured using a scale that compared generic and brandname drugs across four domains. Negative beliefs about generics were associated with non-white race, lower levels of education and income and having Medicaid coverage. Individuals with low health literacy and who reported that their physicians had poor communication skills were more likely to hold negative views. A recent study in Malaysia[29] explored consumer perceptions and knowledge about the issues of generic medicines. Survey forms were given to 400 respondents on an annual university open day for 5 consecutive days. Analysis of the 396 usable forms revealed that only 28.3% respondents were aware of the term generic medicine. Seventy per cent of the respondents were unaware of the marketing of generic medicines with different names, and 34% of the respondents stated that information about generic medicines was passed to them by pharmacists. Most of the consumers (64%) showed their understanding about generics being less costly than their branded counterparts and 32% perceived generics to cause more side effects. This survey showed a gap in consumer knowledge and understanding about generic medicines; educational outreach by health care providers can be a key to increase generic uptake. Table 1 presents a comparison of the reviewed studies, outlining methodologies, study setting, sample size, outcomes and limitations.

Discussion This review encompassed 20 studies on consumers’ views and their perceptions of generic prescription and non-prescription medicines. Based on the review undertaken, the majority of the consumers have mixed reactions towards the acceptance of generic medications. Although a positive attitude seems to have remained fairly stable across the years, as approximately 40–60% of consumers from the studies reviewed held favourable views about generic medications, a positive attitude does not necessarily translate to increased use of generic drug products. In a Florida-based study,[11] irrespective of the cost savings, 66% of the older respondents, even those with lower incomes, rejected lower-cost generic alternatives and cited

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Consumers’ views on generic medicines

them to be less effective. The studies we reviewed indicated several probable reasons for this discrepancy. For example, differences were found according to the economic development of the country, whether a developed or developing nation. Except for two studies from Brazil[22] and Malaysia,[29] no other studies were retrieved regarding consumers’ views about generic medications in developing countries. In developing countries where approximately 77% of medicine expenditures are out of pocket,[30] low cost is an important advantage of generic drugs.[31] This review has managed to contribute substantial additional information on consumers’ views about generic medicines, depicting the diversity across different countries, in addition to what has not been reported in the literature.[32] The narrative review was not intended to be exhaustive, but merely an attempt to examine the general trend of consumers’ views towards generic medicines over time. However, the review has a number of limitations. Most notable was the limitation of access to databases subscribed to by our university library; as a result, important studies available through other databases might have been missed. Another major drawback was that studies published in languages other than English were excluded from the review. This review has reaffirmed that the pharmaceutical reimbursement system implemented in a particular country has an effect on consumers’ use of generic drugs. If a third party pays for the medication or if there were no differences in co-payments between branded and generic drugs, a branded product is preferred. Consumers tended to look more favourably on generic medications as the difference in co-payments increased.[32] Interestingly, two of the studies[16,19] showed financial incentives to be strong predictors of generic prescription drug use. Moreover, these studies also ascertained the role of the pharmacist in patient education for increasing generic drug use. It is worthwhile to mention that implementation of policy changes, such as the adoption of new legislation for drug patenting in Spain[21] and the adoption of a policy on generic drugs in Brazil,[22] would result in more positive views of consumers towards generic medicines. Likewise, the findings from the study conducted in Portugal[27] are in line with the study of Ganther and Kreling[19] which showed less inclination towards and acceptance of generic drugs by patients with serious illnesses. Furthermore, demographic and socioeconomic characteristics of consumers have an effect on their views of generic drug products. Among these characteristics we identified the following: income, education level, ethnicity, age, gender and chronicity of the medical condition. In general, individuals with lower incomes and less education held more negative attitudes towards, and were less knowledgeable about, generic drugs than were those with higher incomes and more education. Also, low-income non-white seniors mistrusted generic medicines.[28] The influence of age was mixed. Several studies indicated that older consumers held more negative views, but others found that younger individuals held more negative views. This may mean that there is a segment of the population (young and old) that is brand-conscious and will always view non-branded (generic) drug products with some suspicion.

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In addition, drug product characteristics have important influences on consumer views of generic drug products. Among these characteristics are price, perceived quality, perceived effectiveness and manufacturer reputation. Price of generic drugs is the reason for them to be considered in the first place and the potential savings by consumers play the main role in the spread of generic drugs.[31] Perceived quality, safety, effectiveness and manufacturer reputation are proportionately related to the acceptance of generic drugs and therefore to their increased usage. Similarly, consultation with health care professionals regarding generic medications seems to influence their use. When consumers had talked with their health care professionals about a generic substitute, and these had positive views about generic medicines, the drugs were more likely to be accepted or used. It was also found that past experience and knowledge of generics, and the risks associated with them, were all important influences on consumers’ views of generic drug products. Several studies found that the use of generic products (non-prescription drugs, groceries, etc.) in the past and knowledge or awareness of generic drugs were important influences on current or future use. Also, the more serious or risky a consumer believed a medical condition to be, the less likely he or she would be to choose or accept a generic drug product for treatment.[27,32] Finally, the prescription itself has a substantial effect on use of generic drugs, especially in developing countries where patients seek to buy exactly what is prescribed.[22]

Conclusions As per our literature review, which was focused on developed countries, consumer confidence and knowledge about generic medicines use have increased steadily over time. Mass education efforts, financial incentives and greater communication between patients and health care professionals were seen as major influences on the uptake of generics among consumers. Safety and efficacy issues were viewed as major barriers to the acceptance of generic drug substitutions. The following conclusions and recommendations are provided on the basis of our analyses of the literature published over the past three decades related to consumers’ views of generic drugs. First, more research about consumers’ views on generic drug products should be carried out in developing countries, where cost savings are needed more than in developed countries. This will enable us to contrast the findings with those from the developed world and to reach a universal view. Second, researchers should consider further study of consumers’ decision-making processes regarding generic medications. Third, better communication among patients and health care professionals regarding the equivalency between most branded and generic products should increase the use of generic medications. Finally, mass educational efforts should be directed by consumer and health professional organizations and individual health care practitioners (pharmacists, physicians, nurses and others) towards consumers to make them more aware and to increase their knowledge about generic medications, and to encourage

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them to take an active role in managing their medical conditions. Educational efforts should take into account the concerns of specific groups, such as those with low levels of literacy, to overcome their fears or misconceptions about generic medications.

Declarations Conflict of interest The Author(s) declare(s) that they have no conflicts of interest to disclose. Funding This review received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Acknowledgement This paper is dedicated to the late Mr. Nabil Abdo Al-Gedadi who passed away peacefully in 2008. Nabil was instrumental in devising the first version of this manuscript and his sudden demise is a great loss for all the authors.

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