Challenges of Older Patients’ Knowledge About Warfarin Therapy

Abstract

Objective: To review the challenges of warfarin education for older patients (aged 65 years or older) in terms of knowledge, access to warfarin education, and education resources. Methods: A quasi-systematic review of the literature was performed via electronic database searches (eg, Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, International Pharmaceutical Abstracts, Meditext, and Google Scholar) from 1990 to May 2011. Results: The 62 articles reviewed found that improved patient knowledge results in better anticoagulation control. The review also found that between 50% and 80% of older patients have inadequate knowledge about the basic aspects of warfarin therapy (eg, action, benefits and risks, interactions with other drugs or foods, international normalized ratio management). Demographic factors, such as advancing age, lower family income, and limited health literacy, were found to inversely affect patients’ warfarin knowledge, and access to warfarin education and information resources were often suboptimal in different practice settings. Finally, a number of educational strategies and resources that could be readily incorporated to improve the effectiveness of current warfarin education programs were extracted from the review. Conclusion: This comprehensive review highlights that education about warfarin in older patients is currently suboptimal and may in part contribute to poor therapeutic outcomes. This review article also acknowledges the need to identify, target, and develop educational strategies and resources to further improve older patients’ knowledge about their warfarin therapy.

Introduction

Warfarin is the most widely prescribed oral anticoagulant in the world. ¹ While alternative agents have recently become available for the management of thromboembolic complications, they are not without risks and are associated with significant treatment costs,^1-3 which is why warfarin will remain a primary therapeutic option. ⁴ The continued use of warfarin is challenged by its complex pharmacology and inherent risk of adverse outcomes, which mandate that routine therapeutic drug monitoring is undertaken to ensure safe and effective therapy.^5-8

Individuals most likely to benefit from warfarin therapy are generally older patients with chronic risk factors for thromboembolism requiring long-term or indefinite oral anticoagulation therapy, for instance, in the management of atrial fibrillation.^9,10 Despite abundant evidence to support its use, various studies have reported that warfarin therapy remains underused in this group of patients.^6,11-16 Some of the most frequently cited barriers to warfarin use by physicians include uncertainty of patient compliance with monitoring, dietary implications, and fear of hemorrhagic complications. Experts suggest that the use of oral anticoagulants can be promoted by increasing both patient and physician education about the potential barriers. ¹⁰

Warfarin is a major contributor to potentially preventable drug-related adverse events,^17,18 partly due to inadequate patient knowledge. ¹⁹ Older individuals are particularly at greater risk of experiencing serious adverse events from oral anticoagulation therapy, highlighting the critical balance between risk and benefit. ¹ Clinicians have previously cited a reluctance to prescribe warfarin because of its impact on diet, drug interactions, and need for monitoring, ¹⁶ all of which rely on patient adherence and treatment instructions and which is therefore dependent on effective patient education.^20,21

This article cites important issues in the published literature relating to older patients’ (aged 65 years or more) knowledge about warfarin and their access to warfarin education. It highlights the importance of older patients’ knowledge about warfarin in relation to therapeutic outcomes, the level of their knowledge about warfarin therapy, the demographic factors that may influence their knowledge about warfarin, older patients’ access to warfarin education in different practice settings, and education strategies and their impact on therapy outcomes.

Methods

Data Sources

A quasi-systematic review (ie, a review that often attends to some details of a truly systematic review but misses the essential spirit of critical analysis ²² ) of recent literature regarding patient education about warfarin therapy was performed. The following electronic databases were searched to retrieve original articles, review papers, and other publications: Medline via OvidSP (1950-present), Embase (1966-present), Cumulative Index to Nursing and Allied Health Literature (CINAHL) via Ebsco (1982-present), International Pharmaceutical Abstracts via OvidSP (1950-present), Meditext via Informit online (1995-present), and Google Scholar. A time span of approximately 20 years (1990–May 2011) was selected because it was during this time that many pivotal studies relating to patient education, therapeutic benefits, and economic analyses of warfarin use in different settings were conducted.^23-31 Being a quasi-systematic review, the time was considered sufficient by the authors to include a comprehensive pool of contemporary publications.

Search Strategies

A 2-tiered search strategy was initially developed for the database searches. A generalized search was employed during tier 1 using the keywords/MeSH headings warfarin and oral anticoagulant. More specific searches were then performed in tier 2 using a number of relevant keywords/MeSH headings such as health information, medicine information, patient education, patient counseling, medication counseling, health education, patient information needs, information-seeking behavior, access to information, source of information, patient knowledge, and health knowledge. Both warfarin and oral anticoagulant were used as search terms; however, only articles relating to warfarin were included for review. Other oral anticoagulants were not included in the review. The search was restricted to the English language, studies involving human subjects, patients aged 65 years or older, and original articles and review papers. With regard to the handling of review papers, which included both critical/narrative and systematic reviews, only the inferences drawn by the authors of the review were taken into account. Studies covering both simple and more complex interventions (eg, information provision plus self-management) were included in the review. Reference lists of papers included in this critical review were also searched for potentially missed articles. For all of the selected papers, full texts were retrieved and were verified following the review objectives. The literature search, data extraction, and evaluation were principally conducted by the research pharmacist. However, the review procedure was verified by two co-researchers to ensure the reliability and accuracy of the search process.

Results

Literature Retrieval and Characteristics of Patient Population

A total of 62 articles were reviewed and the relevant data extracted. A more detailed schematic representation of the article selection is indicated in Figure 1.

Figure 1.

Schematic presentation for the selection of potential articles included in the review.

Within the 55 original patient intervention studies reviewed, 36 were conducted in community settings, with the other 19 in hospital-based settings. A total of 14 541 older patients were identified as study participants, comprising 51.4% (n = 7470) from community settings and 48.6% (n = 7071) from hospital settings. Two studies pertaining to evaluations of patient information resources did not include human subjects but rather assessed warfarin information brochures only; hence, these were not taken into account when calculating the total patient numbers.

Importance of Knowledge About Warfarin in Relation to Effective Therapeutic Outcomes

There is a general consensus in the literature that improved patient knowledge about warfarin therapy improves therapeutic outcomes.^8,11,32-41 Kagansky et al ⁸ showed that older patients (N = 323) with better knowledge about their warfarin therapy (measured by a warfarin knowledge–testing questionnaire) had 45% of their international normalized ratio (INR) values within the therapeutic range as compared with patients with poorer knowledge (35%; P < .001). Tang et al ³⁴ also reported a weak but positive correlation between patients’ knowledge of warfarin therapy and the number of INR values that were within the target range (P = .024). These findings were supported by another study, ¹¹ which reported that older patients (N = 125) who possessed a better understanding of warfarin therapy spent about 70% of the time within the therapeutic INR range as compared with those with a poorer understanding (63%). The results of this latter study, however, were not statistically significant, reflecting the large amount of variability (eg, in concordance and in perceived benefits and barriers of warfarin therapy) within each group and also possibly due to the limited number of patients included. Interestingly, evidence from other studies, such as Davis et al (N = 52), ⁴² The Newcastle Anticoagulation Study Group (N = 242), ⁴³ Arnsten et al (N = 132), ⁴⁴ Fang et al (N = 179), ⁴⁵ and Baker et al (N = 260) ⁴⁶ suggested no association between patients’ warfarin knowledge and anticoagulation control. Results of these latter studies, however, cannot be generalized because of their use of small sample sizes,^42,44,45 retrospective and/or cross-sectional data evaluation techniques,^42-45 limited number of variables relating to patient knowledge measured, ⁴² and use of nonstandardized data collection techniques. ⁴⁶

Another important issue with regard to warfarin knowledge and therapeutic outcomes identified in this review was the inverse relationship between an individual patient’s level of knowledge about warfarin and the rate of adverse outcomes.^8,34,47-49 In relation to adverse events, specifically haemorrhage, the study by Pernod et al ⁴⁸ reported significantly fewer bleeding events (n = 3, 1.9%) in the patients who had better knowledge about warfarin compared with those patients who had a poor level of knowledge (n = 12, 8.5%; P = .01). Similarly, Kagansky et al ⁸ found that the rate of major bleeding events was highest among patients who had poor knowledge about warfarin, reporting 5.2 bleeding events/1000 patient-months, compared with only 0.5 bleeding events/1000 patient-months among the patients who had satisfactory knowledge (P < .001). Beyth et al ⁵⁰ also showed the positive effects of patient knowledge on clinical outcomes, reporting a reduction in hospitalizations among patients receiving structured warfarin education compared with those in a control group (3 vs 9 hospitalizations, respectively, out of a total of 12 hospitalizations; P = .08).

Deficiencies in Patient Knowledge About Basic Aspects of Warfarin Therapy

Evidence from the review suggests older patients’ knowledge about their warfarin therapy is generally poor, with between 50% and 80% of patients having little knowledge about important basic aspects. ^* It is important, however, to highlight that nonvalidated and purpose-built warfarin knowledge–testing instruments were used in many of the studies^{36,47,49,51,53,55,58-60} when assessing patient knowledge about warfarin, unlike the recent studies conducted by Winans et al ⁶¹ and Baker et al. ⁴⁶

*

References 19, 33, 34, 36, 37, 42, 43, 47, 49, 51-57.

A UK study ⁵³ revealed that as many as 81% of patients (n = 93) receiving warfarin therapy had no knowledge about its benefits with regard to the treatment of their medical condition. Furthermore, evidence from this review indicates that between 45% and 70% of older patients on warfarin therapy had insufficient knowledge about the potential risks associated with their treatment.^{49,53,58-60,62} Other studies highlighted that only between 15% and 57% of the older patients knew their own INR targets or therapeutic ranges.^47,53,63 Also, Lane et al ⁵³ found that approximately 63% of patients were unaware of factors such as other medications and diet that could affect their INR levels.

This review also found that older patients’ knowledge about potential drug-food interactions with warfarin was poor, with as many as 60% to 80% of the patients being unaware that such interactions could occur.^36,42,47,63 Notably, between 22% and 49% of older patients receiving warfarin therapy were unaware of the restrictions of alcohol use required when taking warfarin.^49,51,55

Interestingly, Baker et al, ⁴⁶ in a single-center, cross-sectional study, showed that 74% (N = 185) of patients receiving long-term warfarin therapy had achieved a good warfarin knowledge score (78%) based on the validated 29-point Anticoagulation Knowledge Assessment instrument. They did, however, suggest that the score may have been inflated because of the self-completed questionnaire completed at home with possible assistance from others.

Demographic Factors Influencing Patients’ Knowledge About Warfarin

According to the evidence in this review, it appears that increasing age negatively affects both knowledge about warfarin therapy^34,47 and the retention of warfarin information over time.^35,64 In their study, Tang et al ³⁴ found that the mean warfarin knowledge scores (out of a possible total score of 1.0) declined with advancing age; patients <65 years old scored 0.47; patients 65 to 74 years old scored 0.44; and patients>75 years old scored 0.39. Similarly, McCabe et al ⁴⁷ found that patients aged between 65 and 74 years had knowledge scores of 26.6 (out of a possible 50) as compared with 19.1 for those aged between 75 and 94 years (P = .001).

Unlike gender, which was not found to influence patients’ knowledge about their warfarin therapy,^33,34,47 various sociodemographic factors such as lower family income, limited health literacy, unemployment status, and lower education levels appeared to negatively influence patients’ knowledge. ^† Hu et al ³³ reported that patients who had an annual family income of less than US $25 000 achieved significantly lower knowledge scores compared with patients who had higher family incomes (knowledge score 13.1 vs 14.7 out of a total of 20; P = .007).

†

References 33, 34,45, 47, 52, 58-60, 65, 66

There is very limited data regarding the influence of ethnicity on knowledge about warfarin. A small number of studies^59,60,66 highlighted that knowledge about warfarin is suboptimal among ethnic patients who are immigrants in English-speaking countries; however, older age and low educational status (contributing to low health literacy) appear to be more significant influences on knowledge than ethnicity per se in these patients. A key issue arising from studies involving ethnically diverse patient groups is a perceived lack of engagement in decision-making processes regarding warfarin therapy because patients are unable to fully comprehend the information (due to language barriers) provided verbally during health consultations.^59,66

Accessibility to Warfarin Education for Patients in Different Clinical Practice Settings

The review found that provision of warfarin education and/or information in both community and hospital settings was inadequate, that is, a small proportion of patients received warfarin education^8,19,34,67 or unsatisfactory warfarin education (ie, a lack of appropriate information or a lack of clarity of the information) for those older patients who had received information about warfarin.^8,52

Access to warfarin education for patients in the community settings

Overall, the provision of warfarin education for patients in community settings is generally considered to be inadequate in terms of accessibility to both information sources and resources.^16,34,49,51 This review found that most (between 45% to 88%) older patients in community settings regarded their treating physicians as the main sources of information about their warfarin therapy.^34,51,63 This is supported to some extent by a recent Australian study, ¹⁸ which found that only 39% (n = 36) of general practitioners (GPs) considered that it was their responsibility to deliver warfarin education to their patients. The review also found that a comparatively small proportion of patients indicated pharmacists (0.8%–27%)^17,34,51,68 and nurses (1.6%-50%)^34,51,68 as their major sources of information about warfarin therapy. This represents an underutilization of the available resources of warfarin educators because patients often have limited access to their GP, who may not have prioritized discussing warfarin therapy during their consultations times. ⁵² Similarly, this could also be considered problematic in terms of being satisfactory for the older patients because, according to Tang et al, ³⁴ only 49% of the patients reported having received a warfarin booklet from their GPs, which would be important in terms of reinforcement and providing follow-up information about their warfarin therapy.

Currently, many older patients in community settings are being treated by anticoagulation services, which provide a wide range of services such as INR monitoring, warfarin dosage adjustment, and, supposedly, ongoing education about their warfarin therapy.^11,34 Despite the common perception that these patients receive superior education about their warfarin therapy, ⁶⁰ between 17% and 35% of them still do not receive any education about basic aspects of their warfarin therapy.^49,69

Factors that may contribute to inadequate patient education for older patients about warfarin in the community setting include time constraints, availability of resources, and cognitive decline in old age. Other factors are beyond the control of health care providers, such as poor patient recall, learning difficulties of older patients due to age-related cognitive impairments, and patient complacency with the education provided, and may have contributed to information deficits in this setting or, for that matter, any other setting.^16,60

Access to warfarin education for hospital inpatients

This review also suggests that patient education about warfarin in the hospital setting is also inadequate.^16,47,56 Kagansky et al ⁸ and Cheah and Martens ¹⁹ identified that between 16% and 61% of hospital inpatients reported not having received any warfarin education during their hospital stay. On discharge from hospital, only 30% to 57% of patients reported having received any type of warfarin information from hospital-based health professionals (including physicians).^19,70 Kagansky et al ⁸ found that only 21% of patients who received in-hospital warfarin education considered it to have been satisfactory. The factors contributing to the satisfaction with the warfarin education were mostly related to the amount, content, clarity, and usefulness of information provided to patients.^8,67

Education Strategies for Improving Older Patients’ Knowledge About Warfarin

In recognition of the reported knowledge deficits, several structured and interventional education strategies (eg, individualized face-to-face verbal consultations, group-based patient education, and other) about warfarin have been evaluated and reported in the literature.^{11,37,50,53,64,67,71} These strategies are described as follows.

Individual face-to-face patient education session

Interventions and strategies to improve the education of patients taking warfarin have, to date, largely focused on providing individual face-to-face counseling by key health care professionals within their respective practice settings (eg, GPs counseling patients in their surgeries or community pharmacists counseling their customers in their pharmacies).^34,48,53,67 This mode of education is most often used because it is convenient, easy to deliver, and allows the educator to target the patient’s individual needs.^35,37,71

Group-based warfarin education session

Group-based education sessions have been successfully implemented in environments where it is feasible to convene a group of patients, such as in a hospital and/or in anticoagulation clinics.^11,37,71 This mode of patient education may also include the use of prerecorded information sessions, such as videos.^64,71 In addition to the time-saving advantage of group-based education approaches, other advantages cited in the literature include patient-peer support and the opportunity to learn from their peers about alternative aspects of their therapy. ¹⁶

Written information for warfarin education

The review identified that written warfarin information resources, available as both printed materials and via the Internet, could not be read or understood by between 50% and 88% of the older patient population.^58,72 Bajorek et al ¹⁶ further reported that both health professionals and patients perceived existing written information materials to be suboptimal in terms of content regarding day-to-day warfarin management issues (eg, interactions with other drugs or foods). Given the suboptimal nature of existing warfarin-related written information materials, ¹⁶ various strategies have been suggested in the reviewed literature to improve the comprehensibility and usability of these materials.

The use of specially designed written materials that contain relevant figures or images, pictograms, larger font or page size, and other formatting elements that could improve the comprehensibility of written materials, especially for older patients, has been proposed in the literature.^34,48,72 The use of cue cards that contain short but important pieces of information was similarly suggested. ⁵⁴ Although these could help in tailoring written materials for older patients receiving warfarin therapy, to date, no information about the practical uses of these different strategies has been found in the literature.

Audiovisual resources for warfarin education

Audiovisual media that portray the health care professional talking to the patient about their warfarin therapy are sometimes used as a lateral extension of conventional patient education interventions. ⁶⁴ This prerecorded, multimedia, face-to-face counseling disseminates information to patients in any treatment setting, including their own homes. The potential of this media as a resource is acknowledged in an Australian study, ¹⁶ where health care professionals involved in the management of warfarin therapy recommended the use of television campaigns for educating patients, particularly regarding the prevalent misconceptions regarding warfarin therapy.

Basic aspects in warfarin education programs

Integral to effective warfarin education programs is the inclusion of a minimum set of basic aspects targeting patient knowledge and understanding about warfarin therapy, irrespective of who is providing the education (eg, physician, pharmacist, nurse).^71,73 These basic aspects, as suggested in the literature, include the name of the medicine, mode of action, adverse events, interactions with other drugs or foods, issues related to INR monitoring, the importance of good adherence, lifestyle behavioral adjustments, managing emergency situations such as missed or underdoses/overdoses, and recognizing signs of bleeding complications.^{11,34,37,48,50,53,67,71} Importantly, while some of the reviewed education programs have included most of these aspects,^37,48,67 others focused primarily on just a few.^34,50,71 In most cases, the selection and inclusion of the basic information about warfarin within patient education programs was primarily decided by the health care personnel providing the education.^{34,50,64,67,71}

Effects of Education Interventions on the Level of Control of Therapy and Outcomes by Improving the Patient’s Knowledge

Various interventions^{11,48,53,63,64,71} have been developed and trialed on patients to evaluate their impact on the level of control of therapy and outcomes through improved warfarin education for patients. In a UK-based study, ⁵³ patients who received a structured education session had significant knowledge gains, particularly regarding understanding INR targets (67% patients vs 56% at baseline, P = .001) and factors affecting INR values (58% patients vs 37% at baseline, P = .014) when compared with their baseline knowledge status. In this study, patients from an anticoagulation clinic received individualized, face-to-face education from their treating physicians along with a purpose-designed warfarin booklet. Furthermore, in a multicenter study, ⁴⁸ patients from both community and hospital settings who received a specifically designed individualized education program (including face-to-face verbal consultation from members of a multidisciplinary team, a picture book describing the disease and treatment, and a specific booklet summarizing the information) achieved higher mean warfarin knowledge scores (13.9 out of a total score of 20) when compared with the control group (mean score, 12.4), who received unstructured warfarin counseling sessions (P = .08). The latter study ⁴⁸ also reported a statistically significant (P < .01) cumulative risk reduction in major bleeding events in the experimental group who had received warfarin education.

In a US–based study, ⁷¹ 180 anticoagulation, clinic-based patients were educated in groups of 15 by either a pharmacist or a nurse via an hour-long slide presentation. The study showed that significantly more patients had better knowledge about the important aspects of warfarin therapy after the intervention, particularly about the importance of the INR test (91% patients vs 36% at baseline; P < .001) and effects of vitamin K on the therapy (96% patients vs 49% at baseline; P < .001), as compared with their baseline knowledge about warfarin. Furthermore, Khan et al ¹¹ demonstrated a significant decline in the INR standard deviation (SD) by 0.26 (P < .0001) in the group receiving education alone, 0.24 (P < .0001) in the group allocated to education and self-monitoring, and 0.16 (P = .003) in the control group who had received usual care. However, intergroup comparisons showed no statistically significant difference in the decline of INR SD (intervention groups 0.25 vs control group 0.16; P = .12), which may be because of, first, the large amount of variability within each group (eg, in concordance and in perceived benefits and barriers of warfarin therapy) and, second, possibly due to the limited number of patients who were studied.

Mazor et al ⁶⁴ showed that 317 intervention patients (56% of whom were aged 65 years and older) who received and watched mailed copies of videos in their homes depicting a virtual face-to-face patient education session about warfarin management (unknown length and duration) had significant knowledge gains measured by knowledge-testing questionnaires (68% correct answers of the total 22 questions) when compared with the control group (57% correct answers; P < .001) who received the usual, unstructured education.

Discussion

The main focus of this review article was to highlight the level of, and access to, warfarin education/information and the effects of existing warfarin education interventions on patient knowledge and therapeutic outcomes.

The complexity of warfarin therapy is such that the patients’ command of anticoagulation-related knowledge is a very important component in maintaining optimal control of the therapy and reducing related adverse events. ⁷⁴ This review highlights that a significant proportion of older patients have deficits in their knowledge regarding warfarin, although it is generally accepted that patients on warfarin therapy receive more comprehensive warfarin information from their health professionals when compared with patients taking other types of regular medications. ⁶² Nevertheless, the apparent lack of adequate knowledge has considerable clinical importance as it diminishes therapeutic outcomes in oral anticoagulation therapy, especially in the more vulnerable, older patient population. Because of the use of nonvalidated and purpose-built knowledge testing tools reported in the reviewed literature, it is difficult to judge the actual prevalence of knowledge deficits among patients receiving warfarin therapy. Although 2 validated knowledge-testing tools^32,75 have been identified in the literature, for reasons not stated, these have not been commonly used in the reviewed articles, apart from being described as pilot studies and the 2 recently published studies by Winans et al ⁶¹ and Baker et al ⁴⁶ as mentioned before. The authors suggest further investigation to determine the characteristics and actual prevalence of older patients’ knowledge deficits about warfarin by using validated and standard knowledge-evaluation methods.

Patients’ age^34,47 and other demographic factors such as poor family income, limited health literacy, unemployment, lower education levels, ^‡ and, potentially, ethnicity to some extent^59,60,66 have been found to negatively affect patient knowledge about warfarin. The provision of additional resources such as audiovisual/multimedia resources (when available), pictograms, and/or cue cards could also be recommended to help improve their warfarin knowledge and understanding. These flexible delivery resources may help deliver lengthy and time-consuming information more efficiently and may also provide patients with ample time to process the information during an education session. As an added advantage, the audiovisual resources can be repeated at the patient’s convenience without burdening the health care professional. However, the wider use of audiovisual patient education resources may be restricted by the need for specific equipment to play the videos/DVDs and/or operational skills, suggesting the need for exploring other audiovisual media such as public television (given its effectiveness in other areas of medicine).^16,64

‡

References 33, 34, 45, 47, 52, 58-60, 65, 66

On commencement of warfarin therapy, patients generally receive an unstructured, verbal education session from their health care provider that includes the basic aspects of their warfarin therapy. ³⁷ In some circumstances, patients who are keen may also seek additional information from various other sources (eg, community pharmacist, nurses, the Internet).^33,34 This review, however, highlights the current lack of access or availability of suitable warfarin education and/or information resources in both community and hospital settings. In addition, an underutilization of the available resources of warfarin education by patients is also apparent in this review. Inadequate provision of warfarin education in the hospital settings is particularly of concern since a large proportion of patients commence warfarin therapy in hospitals and are at a 10-fold risk of bleeding within the first month of therapy, postdischarge. ¹⁹ Furthermore, lack of adequate access to warfarin education is a major concern for older patients who are increasingly being prescribed warfarin therapy for chronic conditions such as atrial fibrillation, given their susceptibility to warfarin-related adverse events, which are further potentiated by poor knowledge about their warfarin therapy. ¹⁶ It is therefore imperative that older patients in particular should be provided with appropriate and suitable warfarin education and/or information sessions, reinforcement, and follow-up^76,77 to ensure that they retain the information provided.^35,64

The time or resource constraints of health care providers, which have the potential to affect the availability and the quality of education provided,^17,18,21 are real and are often cited as a major barrier to patient education in the hospital settings of many developed countries such as Australia and the United States. ⁷⁸ A multidisciplinary approach inclusive of pharmacists, nurses, and dieticians could be helpful in educating patients about their warfarin therapy in busy treatment settings, such as hospitals. ¹⁷ For other developed countries (eg, European countries), the resource implications and needs may be different; however, this review’s exclusion criteria (ie, non-English language) may have precluded access to this relevant information.

For warfarin education to be effective, it is generally agreed by patients and/or their carers that both verbal and written patient information are equally important. ¹⁶ Interestingly, even though this review highlighted the importance of providing simple and easy-to-read written information about warfarin, which to date appears to be generally unavailable, it did not identify any findings about the use of appropriate verbal communication skills when speaking to older patients. Given that evidence from other research^79-81 has emphasized that effective verbal communication between health practitioners and patients can be achieved by incorporating simple strategies such as using simple language; speaking slowly; repeating and reinforcing key points by incorporating the “teach-back” method, whereby the patient is asked to repeat back what they have heard and what it means to them; encouraging them to ask questions; and not giving too many directives that may overwhelm them, it seems that this would be an important area for future research, especially with regard to incorporating such strategies into effective education programs.

The review found that both individual and group-based education sessions could effectively educate older patients. Given the need to offer older patients reinforcement and follow up, offering group-based education in addition to individual education would be beneficial, particularly in resource-poor settings, such as hospital settings. At the same time, it is also important to consider the limitations of group-based education sessions, which include the difficulty in scheduling the group session and inability to meet individual information needs. ⁷¹ In the reviewed literature, methodological issues arose relating to the design and mode of implementation of educational interventions, which will require improvements. Also, given the wide variability of basic aspects (eg, action, benefits and risks, interactions with other drugs or foods, and INR management) in the existing education programs, it is important to ensure that these aspects are carefully selected and included in future education programs to inform older patients more effectively and appropriately.

The review encounters several limitations. Although every effort was made to include a comprehensive pool of relevant literature, the quasi-systematic review method may have excluded some potential papers from being included, and the exclusion of non–English-language papers may also have been a limitation. Furthermore, following from the objectives of the review, other important issues relevant to anticoagulation management (eg, self-management or monitoring by patients, medication adherence, and anticoagulation control) have been either discussed only very briefly or excluded to keep the focus on the scope of the review.

Practice Implications

Patient education and relevant resources are currently applied in an ad hoc manner in all facets of education about warfarin. It is, however, timely and important now to identify, target, and develop (where appropriate) effective educational materials and resources and to incorporate them into an educational strategy that improves knowledge and therapeutic outcomes in warfarin therapy, especially among the older patient population. Based on the literature reviewed, a number of practice points have been outlined (Box 1) to help practitioners improve the education of older persons about their warfarin.

Box 1.

Potential Practice Points That May Help Practitioners Improve the Education of Older Patients About Warfarin

• Sociodemographic factors, which can negatively affect warfarin knowledge and understanding, need to be taken into consideration when developing warfarin education programs. These factors include older patients, low income, unemployment status, low education levels, poor health literacy skills, and, possibly, ethnicity.

• Provision of adequate and appropriate warfarin education services to patients may require coordinated efforts from all health professionals (eg, physicians, pharmacists, nurses) to ensure that patient education is provided consistently and in a structured format. Also, all patients commenced on warfarin therapy, in particular hospital inpatients, should have access to follow-up services within the community.

• Warfarin education programs, both individual and group based, need to be comprehensive and systematically cover the key aspects of warfarin therapy. These key aspects should consist of the name of the medicine, purpose of the therapy (including the risks versus benefits), mode of action, adverse events, interactions with other drugs or foods, issues related to INR monitoring, the importance of good adherence, lifestyle behavioral adjustments, management of emergency situations (eg, missed or underdoses/overdoses) and recognizing signs of bleeding complications.

• Warfarin education resources may be most effective when they include simple and easy-to-understand written information, taking into account readability of the information, as well as presentation, as a supplement to verbal counseling and purpose-designed additional communication tools such as cue cards, audiovisual resources depicting real-life scenarios, and/or socioculturally appropriate images/figures (eg, pictograms/drawings, videotapes/DVDs, online videos, podcasts, television programs, Internet sites).

Conclusion

This comprehensive review highlights that education about warfarin in older patients is currently suboptimal and may in part contribute to poor therapeutic outcomes. This review also acknowledges the need to identify, target, and develop educational strategies and resources to further improve older patients’ knowledge about their warfarin therapy.