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Overcoming the obstacles — the outsider's view
Atherosclerosis 147 Suppl. 1 (1999) S53 – S56 www.elsevier.com/locate/atherosclerosis
Overcoming the obstacles — the outsider’s view Adrian Furnham * Department of Psychology, Uni6ersity College London, Gower Street, London WC1E 6BT, UK Accepted 28 June 1999
Abstract The cost to patients, their relatives, the medical establishment and the economies of individual countries is such that compliance with, or adherence to, prescribed therapy is a major issue. There are relatively simple and systematic measures by which medical specialists can increase patient compliance and so save costs, time and lives. From a psychological perspective, the earlier these measures are instigated, for example before patients are discharged from hospital after an acute coronary syndrome, the greater is the likelihood of patient adherence to treatment. © 1999 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Compliance; Adherence; Health belief model; CHD prevention
1. Introduction The question of the extent to which patients comply with advice and treatment, and the factors that influence this are important areas of concern for clinicians. This paper reviews the psychological and medical literature on compliance, and discusses some of the strategies for enhancing it.
2. Compliance and adherence The term adherence is now preferred to compliance, since it implies active collaboration and is more respectful of the patient’s role, whereas the term compliance suggests that the patient plays a very passive part. Compliance is defined as the ‘extent to which a person’s behaviour in terms of taking medication, following diets or executing lifestyle changes, coincides with the medical or health advice’ [1]. The literature suggests that a compliant patient is passive and obedient in following the doctor’s orders and instructions. Therefore, by implication, non-compliance is a form of deviance for which the patient alone is to blame. Adherence is defined as ‘to continue to give support to, to maintain loyalty, to bind oneself to joining’ and is a better descriptor for collaborative involvement of doctor and * Tel.: +44-171-5045395; fax: +44-171-4364276.
patient in planning and implementing the treatment regimen. It involves the patient actively negotiating and discussing the doctor’s recommendations, stresses the interdependence of the two parties and respects the patient’s autonomy (Table 1). Interestingly, in the course of reviewing the literature on complementary medicine [2], it emerged that one of the main reasons why patients choose complementary medicine is that they feel rejected by orthodox medicine. Patients want to be treated as sophisticated and sceptical clients, who need information so that they can be involved in healthcare decisions. They believe that, unlike conventional medicine, complementary medicine offers them involvement and a sense of partnership.
3. Measuring compliance Non-adherence is a matter of degree, and the extent depends on both the definition and the method of assessment. Patient reports are notoriously unreliable and overestimate the extent to which the patient has in fact adhered with treatment. This may reflect a deliberate intention to deceive the researcher, or it may be the result of forgetfulness or failure to understand the treatment regimen. Doctors also tend to overestimate the patient’s adherence, although other healthcare professionals may be more accurate.
0021-9150/99/$ - see front matter © 1999 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 0 2 1 - 9 1 5 0 ( 9 9 ) 0 0 2 5 6 - 7
A. Furnham / Atherosclerosis 147 (1999) S53–S56
S54
More objective methods of measuring adherence include pill counts, the use of electronic devices that record when the container is opened, checks on the dispensing of prescriptions and direct measures such as measurements of the level of the drug or metabolite in blood or urine samples. Alternatively, the expected effect of treatment can be measured, such as a fall in blood pressure or a decrease in cholesterol levels. Collectively, the evidence suggests that at least 30– 45% of patients do not take their medication as prescribed [3–5]. This is irrespective of the type of drug, the nature and severity of the disease and the likely prognosis. From the patient’s perspective, non-adherence is likely to result in the prolongation of an acute illness, or inadequate control of a chronic condition. It has been estimated that, in the UK, non-adherence may result in a 5–10% increase in visits to the doctor, a 10 – 20% increase in prescriptions, a 5 – 10% increase in the number of patients needing additional days off work and, in the most extreme cases, avoidable hospitalization [6]. Figures from the USA suggest that the annual cost of non-adherence with the ten most commonly prescribed drugs exceeds US$1 billion [6].
3.1. Correlates of non-adherence There are no obvious sociodemographic factors that correlate with adherence. Many different hypotheses have been tested and the results are equivocal, with no consistent predictors of adherence. Similarly, the role of personality differences has been investigated, again with disappointing results. However, there are some associations between adherence and the variables incorporated in the health belief model. The health belief model (Fig. 1) [7] was originally devised to explain why people do not adopt prevention measures or attend screening, but it has been extensively used in studies investigating adherence with prescribed medication. The model incorporates patients’
Table 1 Definitions of adherence and compliance Compliance
Adherence
The extent to which the person’s behaviour (taking medication, following diets, lifestyle changes) coincides with medical or health advice. The patient is passive and obedient.
Patient is actively involved in planning and implementing a treatment regimen. Stresses independence and self-regulatory activity. Is more respectful of the patient’s role.
Non-compliance implies deviance and focuses blame on the patient.
Adherence occurs when the patient is: Willing to take treatment. Satisfied that treatment is most appropriate course of action. Fully understands the behaviours required. Not impeded in any way during course of action. Able to monitor progress to the final goal.
understanding of the threat of the disease, which depends on their perception of its seriousness and their own susceptibility. The model also outlines how patients balance the risks and benefits associated with a particular course of action. The likelihood that a particular behaviour will be adopted by patients is also influenced by specific cues to action—cues that trigger behaviour. These factors, together with the individual’s personal health motivation, determine the likelihood of that patient adopting a particular course of action. Thus, in the context of secondary prevention of coronary heart disease, it is important to establish whether the patient understands what a myocardial infarction is, what causes it, the need to continue with treatment for life and the potential benefits of treatment. These factors are all related to adherence. Eliciting and, where possible, changing patient beliefs seem to be most productive in improving adherence.
Fig. 1. The health belief model (from Sheeran and Abraham [7]).
A. Furnham / Atherosclerosis 147 (1999) S53–S56
S55
Table 2 Simple measures to improve adherence with prescribed treatment Category
Type of information
Example of information
Direct
Basic enabling information
When to take medicines during the day–the treatment regimen should be as simple as possible How to use an inhaler
Detailed enabling information on use of non-standard treatments Indirect
Information which: Corrects misunderstanding Alters attitude to treatment Makes the patient more satisfied with their care
Satisfaction with the consultation is the most consistent factor predicting adherence [8]. In the setting of long-term preventative therapy, the best predictor of adherence is early adherence, within 1 – 2 weeks of leaving hospital, indeed even within the hospital itself. Early adherence predicts later adherence, and early adherence is associated with satisfaction with the consultation. Other characteristics of the doctor – patient relationship have less clear-cut relationships with adherence.
4. Strategies for enhancing adherence There are many strategies for improving adherence. Where possible, the course of treatment should be as simple and short as possible; this is clearly not feasible in the case of long-term preventative cardiac therapy, but in this case treatment should preferably be once daily, as is the case with most statins (Table 2). The provision of adequate information clearly plays an important role. However, the crucial factor is an exchange of information, eliciting what the patient knows and believes, and making appropriate changes. In some circumstances, information can negatively influence adherence, for example, over-emphasis on the risks and side-effects of treatment may adversely influence the risk–benefit analysis the patient makes so that they perceive that the risks outweigh the benefits. An excessive amount of information or conflicting information from different sources can also have adverse effects on adherence. When patients are interviewed immediately after a consultation, many can remember very little, even when they are relatively relaxed. It is not entirely clear whether information given first or last has higher impact; however, it seems clear that the information in the middle is lost. Hence, it is a good rule during a consultation to tell the patient what you are going to tell them, then tell them, and finally tell them what you have told them, achieving a primacy and a recency effect.
The ability to drink alcohol while taking certain treatments The lack of addictive potential of steroids. The benefits of treatment A well-designed leaflet relevant to the patient’s needs
There are many ways in which information can influence people positively. Basic enabling information is very important and in this context the patient should be helped to remember the relevant information, by saying, for example, that the medicine should be taken before breakfast, lunch and dinner, rather than simply three times daily. For non-standard treatments, such as an asthma inhaler, detailed information should be given on how to use it. Indirect information, which corrects misunderstanding and clarifies the patient’s attitude to treatment or makes them more satisfied with their care, therefore contributing to improving adherence. For example, it may be important to explain to the patient that they are allowed to drink alcohol while taking the medication, or to reassure them that corticosteroids are not addictive. A clear and well-designed patient information leaflet can be an important contributor to patient satisfaction. Patients are more likely to adhere or comply when they understand the nature of the treatment and are satisfied that the treatment offered is the most appropriate course of action. Patients like to understand fully the treatment and the pattern of behaviour that is required and that they are not impeded in any way during the course of this action. It is also beneficial if patients are able to monitor their progress to the final goal and hence to have their own indicator of the success of treatment. It is important to consider the constraints of the patient’s work and lifestyle, and the regime should be tailored to fit in with the patient’s pattern of behaviour, using significant daily events as cues. Consideration should be given to the use of mechanical aids such as calendar packs or pill boxes with an audible signal. As part of the process of educating and counselling the patient, it is valuable to check the extent to which they have heard, understood and remembered the instructions. It is also important that patients understand what they should do if they miss a dose. Keeping a diary provides a valuable form of feedback, which can enhance adherence, and in some cases it may be appropriate to involve the patient’s partner in monitoring therapy.
S56
A. Furnham / Atherosclerosis 147 (1999) S53–S56
Table 3 Some recent concepts for improving adherence with prescribed therapy E6idence-based medicine and research findings suggest that: Patients are more likely to adhere to drug therapy if it is prescribed in hospital rather than by the primary-care physician after discharge Patients believe that treatment prescribed after they have left hospital is less important Patients are impressed by the seniority/rank/expertise of hospital consultants
Returning to the health belief model, it is clearly important that the patient has an accurate perception of the seriousness of the condition, and the risks and benefits of the treatment. The patient should be satisfied with the amount of information given about the treatment and this depends on the individual: some patients wish to find out everything about their condition while others have very different information needs and wish to know very little. However, the patient should clearly understand the dose, frequency, timing and duration of treatment, and should have information about the rationale of the treatment to understand the regimen. At follow-up, the patient should be asked whether any problems were encountered in following the regimen and be encouraged to express any doubts about it, so that solutions to problems can be identified and the treatment changed if necessary. Again feedback about progress is very important, with self-monitoring where appropriate.
5. Some recent concepts The evidence suggests that drugs prescribed by the consultant in the hospital are perceived as more important than those prescribed by the primary-care physician after discharge. Patients are impressed by seniority and expertise, and this may help to enhance early adherence. If the consultant has time to advise and discuss the prescribed treatment in the hospital setting, under ideal circumstances when the patient’s initial fear is gone, it is likely that adherence will be improved (Table 3). Despite the powerful impact of the consultant, up to 50% of patients report that they do not receive all the information they need [9]. The hospital setting provides a valuable opportunity for patients to get the information necessary for ensuring the establishment of a pattern of taking their treatment. Indeed, the recently revised joint European guidelines recommenda.
tions [10] advocate early initiation of statin therapy within the hospital setting after admission for an acute coronary event. This proactive approach provides a unique opportunity to educate patients and improve adherence with this evidence-based lifelong therapy.
6. Conclusions Enhancing patient adherence requires an effort to understand the issues and practicalities from the patient’s perspective. A good consultation, in which the doctor can find out what the patient believes, and where there is time for the patient to ask questions and for the doctor to provide necessary information and feedback to check the patient’s understanding, will help to ensure that the patient adheres to the regimen. After a myocardial infarction, in the hospital environment, at a time when the patient’s attention is highest, there is a unique and powerful opportunity to influence the patient in a positive way to enhance adherence. A good consultation predicts early adherence, which in turn is a predictor of subsequent adherence.
References [1] Haynes RB. Determinants of compliance: the disease and the mechanics of treatment. In: Haynes RB, Taylor DW, Sackett DL, editors. Compliance in Health Care. Baltimore: John Hopkins University Press, 1979. [2] Vincent C, Furnham A. Complementary Medicine. Chichester: Wiley, 1997. [3] Ley P. Psychological studies of doctor patient communication. In: Rachman S, editor. Contributions to Medical Psychology. Oxford: Pergamon Press, 1976. [4] Department of Health, Education and Welfare. Prescription drug products: patient labelling requirements. Federal Register 1979;44:40016– 41. [5] Meichenbaum D, Turk DC. Facilitating Treatment Adherence. New York: Plenum Press, 1987. [6] Ley P. Compliance among patients. In: Baum A, Newman S, Weinman J, West R, McManus C, editors. Cambridge Handbook of Psychology, Health and Medicine. Cambridge: Cambridge University Press, 1997:281 – 4. [7] Sheeran P, Abraham C. The health belief model. In: Conner M, Norman P, editors. Predicting Health Behaviour. Buckingham: Open University Press, 1996. [8] Ley P. Communicating with Patients. London: Chapman and Hall, 1988. [9] O’Brien M. Compliance among health professionals. In: Baum A, Newman S, Weinman J, West R, McManus C, editors. Cambridge Handbook of Psychology, Health and Medicine. Cambridge: Cambridge University Press, 1997:278 – 81. [10] Recommendations of the Second Joint Task Force of the European and other Societies on Coronary Prevention. Prevention of coronary heart disease in clinical practice. Eur Heart J 1998;19:1434 – 1503.
Overcoming the obstacles — the outsider’s view Adrian Furnham * Department of Psychology, Uni6ersity College London, Gower Street, London WC1E 6BT, UK Accepted 28 June 1999
Abstract The cost to patients, their relatives, the medical establishment and the economies of individual countries is such that compliance with, or adherence to, prescribed therapy is a major issue. There are relatively simple and systematic measures by which medical specialists can increase patient compliance and so save costs, time and lives. From a psychological perspective, the earlier these measures are instigated, for example before patients are discharged from hospital after an acute coronary syndrome, the greater is the likelihood of patient adherence to treatment. © 1999 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Compliance; Adherence; Health belief model; CHD prevention
1. Introduction The question of the extent to which patients comply with advice and treatment, and the factors that influence this are important areas of concern for clinicians. This paper reviews the psychological and medical literature on compliance, and discusses some of the strategies for enhancing it.
2. Compliance and adherence The term adherence is now preferred to compliance, since it implies active collaboration and is more respectful of the patient’s role, whereas the term compliance suggests that the patient plays a very passive part. Compliance is defined as the ‘extent to which a person’s behaviour in terms of taking medication, following diets or executing lifestyle changes, coincides with the medical or health advice’ [1]. The literature suggests that a compliant patient is passive and obedient in following the doctor’s orders and instructions. Therefore, by implication, non-compliance is a form of deviance for which the patient alone is to blame. Adherence is defined as ‘to continue to give support to, to maintain loyalty, to bind oneself to joining’ and is a better descriptor for collaborative involvement of doctor and * Tel.: +44-171-5045395; fax: +44-171-4364276.
patient in planning and implementing the treatment regimen. It involves the patient actively negotiating and discussing the doctor’s recommendations, stresses the interdependence of the two parties and respects the patient’s autonomy (Table 1). Interestingly, in the course of reviewing the literature on complementary medicine [2], it emerged that one of the main reasons why patients choose complementary medicine is that they feel rejected by orthodox medicine. Patients want to be treated as sophisticated and sceptical clients, who need information so that they can be involved in healthcare decisions. They believe that, unlike conventional medicine, complementary medicine offers them involvement and a sense of partnership.
3. Measuring compliance Non-adherence is a matter of degree, and the extent depends on both the definition and the method of assessment. Patient reports are notoriously unreliable and overestimate the extent to which the patient has in fact adhered with treatment. This may reflect a deliberate intention to deceive the researcher, or it may be the result of forgetfulness or failure to understand the treatment regimen. Doctors also tend to overestimate the patient’s adherence, although other healthcare professionals may be more accurate.
0021-9150/99/$ - see front matter © 1999 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 0 2 1 - 9 1 5 0 ( 9 9 ) 0 0 2 5 6 - 7
A. Furnham / Atherosclerosis 147 (1999) S53–S56
S54
More objective methods of measuring adherence include pill counts, the use of electronic devices that record when the container is opened, checks on the dispensing of prescriptions and direct measures such as measurements of the level of the drug or metabolite in blood or urine samples. Alternatively, the expected effect of treatment can be measured, such as a fall in blood pressure or a decrease in cholesterol levels. Collectively, the evidence suggests that at least 30– 45% of patients do not take their medication as prescribed [3–5]. This is irrespective of the type of drug, the nature and severity of the disease and the likely prognosis. From the patient’s perspective, non-adherence is likely to result in the prolongation of an acute illness, or inadequate control of a chronic condition. It has been estimated that, in the UK, non-adherence may result in a 5–10% increase in visits to the doctor, a 10 – 20% increase in prescriptions, a 5 – 10% increase in the number of patients needing additional days off work and, in the most extreme cases, avoidable hospitalization [6]. Figures from the USA suggest that the annual cost of non-adherence with the ten most commonly prescribed drugs exceeds US$1 billion [6].
3.1. Correlates of non-adherence There are no obvious sociodemographic factors that correlate with adherence. Many different hypotheses have been tested and the results are equivocal, with no consistent predictors of adherence. Similarly, the role of personality differences has been investigated, again with disappointing results. However, there are some associations between adherence and the variables incorporated in the health belief model. The health belief model (Fig. 1) [7] was originally devised to explain why people do not adopt prevention measures or attend screening, but it has been extensively used in studies investigating adherence with prescribed medication. The model incorporates patients’
Table 1 Definitions of adherence and compliance Compliance
Adherence
The extent to which the person’s behaviour (taking medication, following diets, lifestyle changes) coincides with medical or health advice. The patient is passive and obedient.
Patient is actively involved in planning and implementing a treatment regimen. Stresses independence and self-regulatory activity. Is more respectful of the patient’s role.
Non-compliance implies deviance and focuses blame on the patient.
Adherence occurs when the patient is: Willing to take treatment. Satisfied that treatment is most appropriate course of action. Fully understands the behaviours required. Not impeded in any way during course of action. Able to monitor progress to the final goal.
understanding of the threat of the disease, which depends on their perception of its seriousness and their own susceptibility. The model also outlines how patients balance the risks and benefits associated with a particular course of action. The likelihood that a particular behaviour will be adopted by patients is also influenced by specific cues to action—cues that trigger behaviour. These factors, together with the individual’s personal health motivation, determine the likelihood of that patient adopting a particular course of action. Thus, in the context of secondary prevention of coronary heart disease, it is important to establish whether the patient understands what a myocardial infarction is, what causes it, the need to continue with treatment for life and the potential benefits of treatment. These factors are all related to adherence. Eliciting and, where possible, changing patient beliefs seem to be most productive in improving adherence.
Fig. 1. The health belief model (from Sheeran and Abraham [7]).
A. Furnham / Atherosclerosis 147 (1999) S53–S56
S55
Table 2 Simple measures to improve adherence with prescribed treatment Category
Type of information
Example of information
Direct
Basic enabling information
When to take medicines during the day–the treatment regimen should be as simple as possible How to use an inhaler
Detailed enabling information on use of non-standard treatments Indirect
Information which: Corrects misunderstanding Alters attitude to treatment Makes the patient more satisfied with their care
Satisfaction with the consultation is the most consistent factor predicting adherence [8]. In the setting of long-term preventative therapy, the best predictor of adherence is early adherence, within 1 – 2 weeks of leaving hospital, indeed even within the hospital itself. Early adherence predicts later adherence, and early adherence is associated with satisfaction with the consultation. Other characteristics of the doctor – patient relationship have less clear-cut relationships with adherence.
4. Strategies for enhancing adherence There are many strategies for improving adherence. Where possible, the course of treatment should be as simple and short as possible; this is clearly not feasible in the case of long-term preventative cardiac therapy, but in this case treatment should preferably be once daily, as is the case with most statins (Table 2). The provision of adequate information clearly plays an important role. However, the crucial factor is an exchange of information, eliciting what the patient knows and believes, and making appropriate changes. In some circumstances, information can negatively influence adherence, for example, over-emphasis on the risks and side-effects of treatment may adversely influence the risk–benefit analysis the patient makes so that they perceive that the risks outweigh the benefits. An excessive amount of information or conflicting information from different sources can also have adverse effects on adherence. When patients are interviewed immediately after a consultation, many can remember very little, even when they are relatively relaxed. It is not entirely clear whether information given first or last has higher impact; however, it seems clear that the information in the middle is lost. Hence, it is a good rule during a consultation to tell the patient what you are going to tell them, then tell them, and finally tell them what you have told them, achieving a primacy and a recency effect.
The ability to drink alcohol while taking certain treatments The lack of addictive potential of steroids. The benefits of treatment A well-designed leaflet relevant to the patient’s needs
There are many ways in which information can influence people positively. Basic enabling information is very important and in this context the patient should be helped to remember the relevant information, by saying, for example, that the medicine should be taken before breakfast, lunch and dinner, rather than simply three times daily. For non-standard treatments, such as an asthma inhaler, detailed information should be given on how to use it. Indirect information, which corrects misunderstanding and clarifies the patient’s attitude to treatment or makes them more satisfied with their care, therefore contributing to improving adherence. For example, it may be important to explain to the patient that they are allowed to drink alcohol while taking the medication, or to reassure them that corticosteroids are not addictive. A clear and well-designed patient information leaflet can be an important contributor to patient satisfaction. Patients are more likely to adhere or comply when they understand the nature of the treatment and are satisfied that the treatment offered is the most appropriate course of action. Patients like to understand fully the treatment and the pattern of behaviour that is required and that they are not impeded in any way during the course of this action. It is also beneficial if patients are able to monitor their progress to the final goal and hence to have their own indicator of the success of treatment. It is important to consider the constraints of the patient’s work and lifestyle, and the regime should be tailored to fit in with the patient’s pattern of behaviour, using significant daily events as cues. Consideration should be given to the use of mechanical aids such as calendar packs or pill boxes with an audible signal. As part of the process of educating and counselling the patient, it is valuable to check the extent to which they have heard, understood and remembered the instructions. It is also important that patients understand what they should do if they miss a dose. Keeping a diary provides a valuable form of feedback, which can enhance adherence, and in some cases it may be appropriate to involve the patient’s partner in monitoring therapy.
S56
A. Furnham / Atherosclerosis 147 (1999) S53–S56
Table 3 Some recent concepts for improving adherence with prescribed therapy E6idence-based medicine and research findings suggest that: Patients are more likely to adhere to drug therapy if it is prescribed in hospital rather than by the primary-care physician after discharge Patients believe that treatment prescribed after they have left hospital is less important Patients are impressed by the seniority/rank/expertise of hospital consultants
Returning to the health belief model, it is clearly important that the patient has an accurate perception of the seriousness of the condition, and the risks and benefits of the treatment. The patient should be satisfied with the amount of information given about the treatment and this depends on the individual: some patients wish to find out everything about their condition while others have very different information needs and wish to know very little. However, the patient should clearly understand the dose, frequency, timing and duration of treatment, and should have information about the rationale of the treatment to understand the regimen. At follow-up, the patient should be asked whether any problems were encountered in following the regimen and be encouraged to express any doubts about it, so that solutions to problems can be identified and the treatment changed if necessary. Again feedback about progress is very important, with self-monitoring where appropriate.
5. Some recent concepts The evidence suggests that drugs prescribed by the consultant in the hospital are perceived as more important than those prescribed by the primary-care physician after discharge. Patients are impressed by seniority and expertise, and this may help to enhance early adherence. If the consultant has time to advise and discuss the prescribed treatment in the hospital setting, under ideal circumstances when the patient’s initial fear is gone, it is likely that adherence will be improved (Table 3). Despite the powerful impact of the consultant, up to 50% of patients report that they do not receive all the information they need [9]. The hospital setting provides a valuable opportunity for patients to get the information necessary for ensuring the establishment of a pattern of taking their treatment. Indeed, the recently revised joint European guidelines recommenda.
tions [10] advocate early initiation of statin therapy within the hospital setting after admission for an acute coronary event. This proactive approach provides a unique opportunity to educate patients and improve adherence with this evidence-based lifelong therapy.
6. Conclusions Enhancing patient adherence requires an effort to understand the issues and practicalities from the patient’s perspective. A good consultation, in which the doctor can find out what the patient believes, and where there is time for the patient to ask questions and for the doctor to provide necessary information and feedback to check the patient’s understanding, will help to ensure that the patient adheres to the regimen. After a myocardial infarction, in the hospital environment, at a time when the patient’s attention is highest, there is a unique and powerful opportunity to influence the patient in a positive way to enhance adherence. A good consultation predicts early adherence, which in turn is a predictor of subsequent adherence.
References [1] Haynes RB. Determinants of compliance: the disease and the mechanics of treatment. In: Haynes RB, Taylor DW, Sackett DL, editors. Compliance in Health Care. Baltimore: John Hopkins University Press, 1979. [2] Vincent C, Furnham A. Complementary Medicine. Chichester: Wiley, 1997. [3] Ley P. Psychological studies of doctor patient communication. In: Rachman S, editor. Contributions to Medical Psychology. Oxford: Pergamon Press, 1976. [4] Department of Health, Education and Welfare. Prescription drug products: patient labelling requirements. Federal Register 1979;44:40016– 41. [5] Meichenbaum D, Turk DC. Facilitating Treatment Adherence. New York: Plenum Press, 1987. [6] Ley P. Compliance among patients. In: Baum A, Newman S, Weinman J, West R, McManus C, editors. Cambridge Handbook of Psychology, Health and Medicine. Cambridge: Cambridge University Press, 1997:281 – 4. [7] Sheeran P, Abraham C. The health belief model. In: Conner M, Norman P, editors. Predicting Health Behaviour. Buckingham: Open University Press, 1996. [8] Ley P. Communicating with Patients. London: Chapman and Hall, 1988. [9] O’Brien M. Compliance among health professionals. In: Baum A, Newman S, Weinman J, West R, McManus C, editors. Cambridge Handbook of Psychology, Health and Medicine. Cambridge: Cambridge University Press, 1997:278 – 81. [10] Recommendations of the Second Joint Task Force of the European and other Societies on Coronary Prevention. Prevention of coronary heart disease in clinical practice. Eur Heart J 1998;19:1434 – 1503.