Dependent on the Patient
Chronic process
Asymptomatic disease
Lack of knowledge of the disease by the patient
Lack of confidence in the benefit of the treatment by the patient
Missing scheduled appointments
Presence of psychological problems
Cognitive impairment
Social isolation
Dependent on the Treatment
Complexity or long duration of treatment
Adverse effects of medication
Inadequate patient-physician relationship
Fragmented attention: lack of coordination
Absence of scheduled periodic appointments
Cost of medication
2 Consequences of Non-compliance
Several results from adherence studies are available. Thus in a study involving more than 18,000 patients followed during 4.6 years, good adherence to antihypertensive treatment involves a lesser degree of morbidity and mortality (HR 0.62 (0.40–0)) (Mazzaglia et al. 2009). Deficiency in compliance has an impact in most of cases in an increase in costs. These are generated due to an increase in hospitalizations and visits to the outpatient centers and emergency departments as well as changes in doses and prescriptions and more invasive diagnostic tests required (Hughes et al. 2001). Only in the United States, approximately 125,000 deaths per year and 33–69 % of the hospital admissions are related to the lack of adherence to treatment, with an estimated total cost of 100 billion dollars annually: 25 billion corresponded to admissions and 70 billion to loss of productivity and premature death (Osterberg and Blaschke 2005; Ho et al. 2006; Dezii 2000; McCarthy 1998; Berg et al. 1993).
Patients with cardiovascular disease that fail to comply with their treatment regimen, have an 80 % increase in the risk of death in the first 120 days after an acute myocardial infarction (Newby et al. 2006). Non adherence to medication increases the risk of death from stroke in patients with hypertension (OR 3.81 (2.35; 3.20)) (Mayor 2013). Another study has shown that patients with diabetes, hypertension, high cholesterol, and heart failure, had higher hospitalization rates if they were low adherent (13 % vs 30 % for diabetics; 19 % vs. 28 % in hypertension) (New England Healthcare 2009). On the other side, there is a study pointing out a possible overestimation of the effect of poor compliance on the final outcomes (LaFleur et al. 2011).
3 Concept of Compliance
We can define compliance as the degree to which the behavior of the patient, in terms of medication, a diet or lifestyle changes, meets up clinical prescription or medical advice. Since compliance implies somehow blaming the patient, other terms have been used. As an example, adherence is defined as the capacity and willingness to comply with a prescribed therapeutic regimen (Sackett and Haynes 1976; Inkster et al. 2006). It is important to distinguish, as Haynes highlights (Haynes et al. 2008) between adherence and concordance in treatments. Adherence is the degree in which a patient meets the prescription ordered by his doctor, but sometimes this can have a guilty connotation. The concordance would be the degree of agreement on the treatment achieved by the patient and the physician. Three prerequisites are required in order that the patient has a good adhesion to treatment: it must be acceptable, understandable and personally manageable (James et al. 2016).
The Spanish Society of Hypertension Working Group on Compliance defines compliance as the extent that the patient assumes the rules or advices given by the physician or health professional, both from the point of view of lifestyle or the pharmacological treatment recommended. It shows the degree of overlap between the guidance given by the professional and the fulfillment by the patient after a fully reasoned decision (Márquez Contreras et al. 1998).
4 Types of Non-compliance
Non-compliance is a dynamic concept that may affect all phases of the clinical process from the first contact with the doctor until the end of the treatment. There is consensus in the literature that patients taking at least 80 % of the tablets are considered compliant.
On the basis of the Medication Event Monitoring System (MEMS) several patterns of non-compliance have been described (Márquez 2008; Márquez et al. 2012):
With the advent of integrated electronic prescribing and dispensing data they can be classified in (Tamblyn et al. 2014; Fischer et al. 2010):
Compliers
Absolute complier: person who takes quite the 100 % of medication
Masked complier: person who takes more than 80 % of medication
Sporadic failure: Non compliance with the treatment one to six times a month
Over complier: person who takes more than 100 % of medication.
Non Complier
Absolute breach: person who takes less than 50 % of medication.
Partial non-compliance: individuals taking between 50 and 80 %.
Medication abandonment: patients definitely stop taking their medication.
Others Patterns
Drug holidays: individuals who do not take their medication for three days.
Predicted non-compliance: repetitive non adherence at certain times.
White coat effect: non compliers individuals that take their medications the days before an appointment.
Time table non-compliance: do not take the medication at the scheduled hours medication hours.
Mixed non-compliers: coexistence of two or more associated patterns.
Primary non adherence: it was defined as failing to fill a new incident prescription.
Persistence or secondary non adherence: the patient stop taking medications soon after filling the first prescription
5 Factors Involved
The general factors involved in adherence of the treatments can be classified in (Rosenson et al. 2016):
Cognitive losses cause forgetfulness of dose or loss of ability to understand the impact of treatments
Psychopathology: the depression, anxiety or high levels of hostility may affect compliance
Functional illiteracy affects to the compression of the treatments.
The interaction with the professionals of health may improve compliance using non-technical words and involving the patients in the decisions.
The lost in the clinical follow-up of patients with chronic diseases affects the adhesion and the final objectives of the treatment
The most frequent barriers are related to the characteristics of the patient and disease (simple forgetfulness, ignorance of the chronic disease condition, retirement (Kivimäki et al. 2013), poor social, health or family support and personal decision of the patient to give up treatment). Some are also dependent on the characteristics of the treatment (side effects, long-term therapies, difficult to understand or to take, inadequate communication, price) (Baroletti and Dell’Orfano 2010). Although age is not a risk factor per se, there are several studies that suggest that non-adherence, intentional or not, is a problem in aged patients. This is due, in part, to the lack of understanding of the schemes available and the forgetfulness, favored by the high proportion of elderly people who live alone, the impairment of cognitive function, the prevalence of co-morbidities and the polimedication (Horne et al. 2005; Wang et al. 2014)
An interesting systematic review with qualitative research methodology concludes that patients with hypertension link together stress and the presence of symptoms (Marshall et al. 2012). This perception justifies treatment abandonment when they perceive less stress or less symptoms. Sometimes they stop treatment if they are afraid of side effects or a possible addiction to treatment. No ethnic or countries differences were detected. A factor who influence in the adherence to treatment is the patient-physician relationship. It is important to know the beliefs and expectations of the patient, as well as the socio-familial support. It is the family in many cases that acts as a reminder of the treatment and can promote a change of conduct. The success of treatment depends on both: therapist and patient. For a solid grip, the doctor requires technics and tools in communication skills (Sanson-Fisher and Clover 1995).
6 Prevalence of Treatment Adherence
According to a systematic reviews, the prevalence of non-compliance with HTA treatment in the world is, at average, 30 % and probably this is one of the main causes of the lack of control of hypertension (Tamblyn et al. 2014; Cramer et al. 2008). The therapeutic compliance prevalence ranges between 40 and 90 % according to the method used to measure, the disease and the population studied. In this sense, Choo and collaborators (Choo et al. 1999) they assessed the validity of self-reported compliance, pharmacy records and counting tablets as measures of antihypertensive drugs compliance against the MEMS standard. Hansen (Hansen et al. 2009) and Horne (Horne et al. 2010) also compared different methods of measurement of compliance, with figures between 80 and 90 %. Other authors that also used MEMS system as control, found a compliance rate around 80 % (Zeller et al. 2007; Santschi et al. 2008). In a series that evaluated the compliance evolution in 3553 patients during 20 years, an increase in compliance was detected, although the final rate was 67.47 % (Márquez et al. 2006). This contrasts with a study performed in non-industrialized countries where the average compliance was 40 % even after using the same method (Qureshi et al. 2007). Besides, Schoenthaler found a compliance rate of 56 % in African Americans (Schoenthaler and Ogedegbe 2008).
The different studies available show conflicting results. It is difficult to obtain significant relations with the compliance variable, as long as this variables depends largely on individual factors that are difficult to assess. Some works highlight that the presence of other chronic diseases associated to high blood pressure adversely affect taking medication: multiple drugs are required for the control of the diseases. So, patients with high cardiovascular risk sometimes use 4 or more drugs to control several diseases that can cause undesired side effects and trigger low adhesion (Morris et al. 2006; Chapman et al. 2005; Gregorie et al. 2006; Sicras et al. 2006). DiMateo and collaborators published a meta-analysis of studies published over nearly six decades. They concluded that patients with severe disease and a poor state of health should be identified as of great risk of being non-compliant with treatment (DiMatteo et al. 2007).
To achieve the therapeutic objectives in hypertension, health professional must consider that each patient has priorities in health and that each person has an “acceptable therapeutic load”; i.e. the maximum number of medications that are considered reasonable to take every day. This number varies from person to person and the physician needs to know it in order to plan treatment (van Duijn et al. 2011). Some authors suggest that non adherence to treatment is induced by the health system. They propose a “minimally disruptive medicine” (May et al. 2009; Dabrh et al. 2015) with 4 principles: determine the load weight which is acceptable for each patient, enhance coordination in clinical practice with an holistic vision, increase the knowledge of the co-morbidity in clinical practice, and prioritize the patient autonomy and its perspective.
7 Methods to Measure Adherence
It is necessary to know the degree of adherence both to make decisions on the follow-up of the patient as to assess the outcome of clinical trials. There are several methods to measure compliance and are classified into direct and indirect (Márquez 2008; MacFadyen and Struthers 1997). In general, the former tend to be more sensitive and specific, but less acceptable to the more invasive.
Direct methods measure the amount of drug, metabolites, or markers found in some body fluids. Methods are more objective and specific but expensive and inaccessible in primary care. They are also inefficient for short half-life drugs. The use of liquid chromatography-mass spectrometry analysis for antihypertensive drugs in urine analysis can detect low compliance in patients with refractory hypertension (Jung et al. 2013; Tomaszewski et al. 2014).
Indirect methods are simple and economic, useful in the clinic, but their disadvantage is that they are not objective and tend to overestimate the adherence to the treatment. They are based on the quantification of the number of tablets or on clinical interviews. These are the most widely used (Table 2).
Table 2
Indirect methods for evaluating compliance of hypertension
Method
Advantages
Disadvantages
Validationa
S
S
PPV
NPV
Based on the table count
Simple count of tablets
Objective, quantifiable
It takes time. It does not detect the drug intake. High price
Gold standard in research studies
Medication Event Monitoring System (MEMS)
Based on the clinical interview
Haynes-Sackett test
Simple, quick. Useful in clinical practice
It overestimates the adhesion
0.33
0.93
0.73
0.69
Test of Morysky
0.49
0.68
0.48
0.68
Other methods
Professional judgment
Simple, fast
Vague
0.28
0.78
0.44
0.64
Assistance to appointments
Simple
It also depends on the health care organization
0.71
0.83
0.43
0.65
Improvement of disease
Simple, easy to apply
Interference from other factors such as co-morbidities
0.53
0.62
0.46
0.68
Knowledge of disease
Simple
Dependent on the level of culture of the patient
0.82
0.41
0.46
0.79
7.1 Clinical Interview-Based Methods Most Commonly Used Are
7.1.1 Haynes-Sackett or Self-Reported Compliance Test (Sackett et al. 1975)
It consists of two parts. The first part avoids a direct question, and in a friendly environment, the following sentence is inserted:
This approach eases the identification of poor adhesion. If the answer is Yes, the patient is non-compliant, and he will be questioned on the tablets taken in the last month. The authors considered complier a patient whose percentage of self-reported compliance is between 80 and 110 % (Stephenson et al. 1993).
“the majority of patients have difficulty taking their tablets, do you have difficulty in taking all your own?”.
7.1.2 Morinsky-Green Test (Morisky Medication Adherence Scale-4 Items, MMAS-4) (Morisky et al. 1986)
It is a questionnaire that can help the professional to identify the poor adherence to antihypertensive treatment. This method has been validated for several chronic diseases, although it was initially developed by Morinsky, Green and Levine to assess compliance with medication in patients with arterial hypertension. A patient is considered a good complier if answers correctly to 4 questions conducted, interspersed in a cordial way, during a conversation about her illness:
There is a version of the questionnaire with 8 items (MMAS-8) (Morisky et al. 2008; Gallagher et al. 2015) It also includes questions on the reasons for non-adherence. It is useful to propose improvement strategies with the patient. The authors determinate low adhesion if the patient has less than 6 correct answers, average adhesion between 6 and 8 and high adhesion if 8 questions are correct.
- 1.
Do you ever forget to take the drugs for your illness?;
- 2.
Do you take your medication at the indicated hours?;
- 3.
Do you stop taking your medication when you feel well?
- 4.
If you ever feel ill, do you quit your treatment?
- 1.
Do you sometimes forget your high blood pressure pills?
- 2.
Over the last two weeks, were there any days that you did not take your high blood pressure medicine?
- 3.
Have you ever cut back or stopped taking your medication without telling your doctor because you felt worse when you took it?
- 4.
Do you sometimes forget to bring along your medication when you travel or leave home?
- 5.
Did you take your hight blood pressure medicine yesterday?
- 6.
Do you sometimes stop taking your medicine when you feel your blood pressure is under control?
- 7.
Taking medication everyday is a real inconvenience for some people. Do you ever feel hassled about sticking to your blood pressure treatment plan?
- 8.
How often do you have difficulty remenbering to take all your blood pressure medication?
7.2 Methods Based on Tablet Quantification
7.2.1 Medication Event Monitoring System (MEMS)
They use the Medication Event Monitoring System (MEMS). These are monitoring systems based on a computerized registration. A microchip placed on the top of the container records the date and the time in which the container is opened. This method is often regarded as the gold standard to measure the adhesion. However, it only detects the opening, not the drug intake, it is not useful in routine clinical practice and it is expensive (Choo et al. 1999; Rosen et al. 2004).
7.2.2 Simple Tablets Count
It is a simple and objective method that compares the number of pills remaining in the container, taking into account the prescribed and the time elapsed between the prescription and the moment when they are measured. A patient is considered good compliant when has consumed 80–100 % of the prescribed tablets. This method tends to overestimate compliance when the patient assumes that it is controlled or if the drug is consumed by another member of the family (Bond and Hussar 1991).
7.3 Additional Compliance Estimations (Márquez et al. 2006)
There are other practical measures, although less used as the Batalla test. This test analyze the degree of knowledge that the patient has of his illness, assuming that the greater patient awareness, the more compliant he will be.
The health professional judgement: based on the opinion of the doctor or the nurse on the patient. The compliance is considered according to the health professional criteria.
The assistance to scheduled appointments: if the patient does not attend the appointments, he is considered a bad compliant.
Method based on the improvement of the treated disease: If hypertension is controlled that would indicate us that the patient is a good complier.
Method based on the medication collection: It is based on the quantification of the medication withdrawn from the pharmacy. The computer records (e-prescribing) report if the patient goes to renew prescriptions on time.
Usually, patients tend to overestimate their adherence to medication, and unless a patient fails to respond to therapy, it is difficult detect a low compliance. If the patient affirms he is a good complier in the clinical interview and we are suspecting non-compliance, we will have to check medication collection in the chemist records and count the tablets used either in the clinic or at home. The count can be masked indicating the patient that we are simultaneously evaluation the expiration. This is the method of choice for general research, but if you want to know the pattern of non-compliance the count will be used through MEMS.
8 Improvement Strategies
8.1 Doctor-Patient Relationship and Treatment Compliance
The style of communication preferred to improve the performance of treatments is a patient-centered style. Thus, it is useful to ask how the patient understands his illness (“what do you known about hypertension?, Which organs can be affected? Do you think that you can control it?). In this way we explore their attitudes and expectations. Patients who understand the personal consequences of their risk factors can manage better the information. In a structured way and to advance in the knowledge of the beliefs of the patient on the arterial hypertension we can use questionnaires based on the Self-Regulatory Model (Ross et al. 2004).
Patients often express their fears to take several drugs or become dependent on them (eg: “When I have to take so many medications, I feel old” “When my labs are normal, I can quit treatment”). Therefore we should ask about the compliance in a non-punitive manner and in the context of the particular values of the patients (eg: “it’s hard to take so many pills, How many times does it happen to you?”). Clinicians must have a long-term perspective and see failures as a learning tool.
The communication strategy to improve adherence should include: the use of non-technical language adapted to the cultural level of each person, personal experience in other drug use, discuss with the patient expectations of benefit and adverse effects, modify ideas and misconceptions, incorporate the preferences of the patient in the treatment plan, give written instructions in a clear and simple way, recommend pill boxes to organize the medication, involve family members, discuss the need to keep the medication despite feeling well. Try to improve the adhesion with a confrontational style with the patient is rarely useful (James et al. 2016).
8.1.1 Shared Decision Making (SDM)
Involving the patient in decision-making and a collaborative integration is beneficial in the management of chronic diseases. We have studies in hypertensive patients where shared decision-making strategy improves therapeutic adherence and control of hypertension. There are studies with SDM in several health care professionals such as physicians, pharmacists, nurses and dieticians. This strategy also showed benefit in poorly controlled hypertension patients with computer-based decision-making tools (van Duijn et al. 2011; Houle et al. 2014; Buhse et al. 2015; Tinsel et al. 2013; Buchholz et al. 2012; Abel and Barksdale 2012; Paasche-Orlow 2011; Roshanov et al. 2011).
8.1.2 Motivational Interview
The motivational interview technics based on the stages of change model of Prochaska and Di Clemente demonstrated some benefit in lifestyle and adherence to treatments (Miller and Rollnick 2013). There are three systematic reviews of clinical trials performed with this technique that presents a statistically significant improvement over conventional interventions with an estimated OR 1.55 (1.40; 1.71). The benefit is particularly promising in weight loss, alcohol and tobacco consumption, sedentary life style self-monitoring and treatment adherence (Lundahl et al. 2013). O’Halloran meta-analysis was performed with studies on people with chronic diseases (O’Halloran et al. 2014). VanBuskirk published another systematic review on primary care population with good results for weight loss and blood pressure. The motivational interview seems to be useful in clinical settings and one single session can improve the willingness to change and an action for health goals for behavior changes (VanBuskirk and Wetherell 2014).
The benefit of the motivational interview has been validated in different healthcare professionals: physicians, nurses and pharmaceuticals (Stewart et al. 2014; Klamerus et al. 2014; Ma et al. 2014; Drevenhorn et al. 2012). The health professional must know in which stage of change is the patient for lifestyles or taking medication changes, as long as the management strategy is different in each stage. The stage of the change of the patient can be classified as shown below:
Not thinking about it at all (pre-contemplation stage)
Thinking about it (contemplation stage)
Ready to start planning (preparation stage)
Ready to implement it (Action stage)
Already making the change (Maintenance stage)
8.2 Factors Associated with Disease and Treatment
We have three Cochrane reviews on different intervention studies to improve compliance and control of hypertension. The different interventions can be classified as:
8.2.1 Health Education to Patients and Professionals
Trials of educational interventions to patients or professionals in general are not related to significant reductions in blood pressure. Clinical studies show that the effects of reducing the BP with changes in lifestyle can be equivalent to monotherapy with drug but the main drawback is the low level of adhesion as time passes (Elmer et al. 2006). There is a consensus that when patients get the information material available in press, pharmacies, medical clinics or other public places offices, it can have a favorable effect on information and motivation of the persons concerned (Guthrie et al. 2007).
A Cochrane review (Glynn et al. 2010) including 20 randomized clinical trials (RCTs) educational interventions directed to the patient was performed. The combination of the results of all RCTs produced mixed results. The mean difference in systolic blood pressure (SBP) and diastolic (DBP) was not statistically significant. With respect on the blood pressure control, there was a trend towards an improvement in the control (Odds Ratio 0.83; 95 % CI: 0.75–0.91). In the same systematic review, ten RCT with educational interventions directed to the health professional were analyzed. These interventions were not associated with a significant decrease in SBP and DBP, nor with a significant increase in the blood pressure control.
8.2.2 Reminder Systems
Glynn reviewed eight RCTs with interventions aimed at reminding the patient appointments and encourage self-monitoring of the efficacy of the treatment. The systems were diverse: from postcards, phone reminder notices by text messages to computer feedbacks. Pooled results were associated with an improvement during follow-up (Odds Ratio of losses to follow up 0.4; 95 % CI: 0.3–0.5). However, we have the study could not determine which reminder system was the most effective (Glynn et al. 2010).
The impact of information and communication technologies in general, and particularly the computerized decision support systems, is discussed in detail in the health security report published by the European Commission in 2007. The report argues that these systems can prevent medical errors and adverse events, promote the participation of the patient with an advantage due to cooperation and adherence (OECD www.oecd.org; Russell et al. 2009).
New technologies, allow that more patients can be controlled, the contacts may be more frequent, with a greater chance to address their concerns, adapt treatment and ultimately improve the adhesion. However, it is important to note that these new care delivery models do not represent a substitute for visits to the physician’s office. Rather, they offer support for the strategy of establishing a good relationship between the patient and the health care professionals. Studies using communication technologies have demonstrated that there are many ways to communicate with patients, with the theoretical advantage of appropriate adjustment and effective care plans.
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