The term adherence describes the adherence to therapy goals that have been jointly established by the patient and physician during the treatment process. The word adherence comes from the Latin verb “adhaerere”, which means “to adhere/cling to something”. Adherence is also often confused with the term compliance. However, there is a difference between the meaning of compliance and adherence. The term compliance has existed in medicine for quite a long time and describes the patient’s observance of the therapeutic measures prescribed by the doctor. In this case, the patient takes a rather passive role in deciding on treatment and therapy goals and performs the actions recommended by the doctor (such as the intake of medication). The patient usually has little say in decisions about therapy goals that are set during the treatment process. Adherence, on the other hand, is a different concept, which has only been developed in recent years and which places a greater focus on the patient and their participation in treatment. The patient is expected to be actively involved in decision-making during the treatment process and works with the doctor to establish the treatment plan. If a patient does not actively participate in the definition of the treatment plan and its implementation, this is referred to as non-adherence. You can read about the consequences of non-adherence and the factors that influence adherence in the next chapter.
Adherence is an important part of treatments, because only the medications which have been taken or the actions that have been performed can be effective. Regular and punctual intake of medications can have a major impact on the effectiveness of medications. The doctor and patient expect a certain effect from the prescribed medication, such as a reduction in blood pressure when blood pressure-lowering medication is prescribed for the treatment of arterial hypertension (high blood pressure). This effect may not occur or may occur only to a reduced extent if the medication is not taken as prescribed by the doctor. As a result, the attending physician may increase the medication dosage or prescribe another medication in addition to those already prescribed.
However, many patients find it difficult to be adherent. Some studies report that adherence to treatment for chronic diseases in industrialized countries is about 50%. That means that 50% of medications prescribed for chronic diseases are taken correctly. Especially in the case of chronic diseases, it is important that the medications or treatments are taken or carried out regularly and reliably. Often, chronic diseases cannot be completely cured. However, through consistent treatment, the severity and symptoms of a disease can be alleviated in many cases. At the same time, a high level of adherence can reduce the occurrence of acute complications, the frequency of hospitalizations and the development of secondary diseases. This can be well illustrated by the example of high blood pressure. Consistent intake of the prescribed antihypertensive medication and adherence to the therapy goals defined together with the doctor are important for a well-controlled blood pressure. This can also reduce the occurrence of acute complications, such as blood pressure abnormalities (a sudden and significant increase in blood pressure), and the development of secondary diseases, such as heart attack, heart failure, stroke or kidney failure.
The lack or absence of adherence to therapy is also referred to as non-adherence. In most cases, there is not just one reason, but a combination of many different reasons why a patient is not adherent. In terms of adherence, the literature talks about five dimensions that influence adherence.
These five dimensions are:
Patient-related factors include the patient’s fear of side effects, the patient’s forgetfulness, their level of motivation to take medication or follow the therapy plan, their confidence in the therapy and its effect, and their knowledge about the disease. A patient who is informed about their disease, its symptoms, and its consequences, is better able to cope with the disease, the therapy and any complications that may arise. But it is not only the patient who can affect the level of adherence.
The doctor or the health care system in general can also influence the patient’s adherence. If a patient feels understood by and trusts their doctor, this can have a positive effect on adherence. If a doctor takes the time to educate the patient about their condition and treatment plan, the adherence can be increased as well.
Another dimension that can influence adherence is represented by therapy-related factors. These include the complexity of the therapy plan, the duration of therapy, and the frequency of changes to the therapy plan. Particularly in the case of very complex medication plans, which include, for example, medications with different dosages and different times of intake, the level of adherence can be negatively impacted. In most cases, long-term therapies, for example in chronic diseases, as well as frequent medication changes can negatively influence adherence.
The above-mentioned factors that can influence adherence are just a few examples for a better understanding. There are many other factors that can have an influence on a patient’s adherence and can vary in severity for each individual patient.
Single pill therapy is the combination of several active ingredients in a single pill with the same dosage of active ingredients as in the individual pills. Single pills are often also called fixed-dose combination drugs and usually contain two active ingredients. In some cases, there are even single pills that contain three or more active ingredients and can thus replace several different tablets that a patient has to take daily. Single pills are already available for the treatment of various diseases, although they still only account for a small proportion of all available drugs. They can already be used for the treatment of cardiovascular diseases, infectious diseases, diabetes and many other diseases. In fact, many different single pills are already available for the treatment of cardiovascular diseases. A typical and very common cardiovascular disease is arterial hypertension (high blood pressure). Many different active ingredients can be used to treat high blood pressure. The European guideline recommends using a combination of two active ingredients when starting drug therapy for hypertension. In addition, it is recommended to use a single pill if possible. This can reduce the number of pills a patient has to take per day. Another example of the use of single pills is the treatment of infectious diseases, such as HIV infection or infection of the stomach with the bacterium Helicobacter pylori, which can very often contribute to the development of stomach ulcers. Here, too, the use of single pills can reduce the number of tablets to be taken.
The biggest advantage of single pill therapy is the reduction in the number of pills a patient has to take per day. In Germany, a great many people have to take several pills a day. More than half of Germans over the age of 70 take 3 or more pills a day. From the age of 75, the number of tablets is even higher. In this age group, every third German citizen takes at least 8 pills. Many studies have shown that patients often feel burdened by the intake of several pills a day and wish to reduce the number of pills. This is referred to as pill burden.
Intake of this high number of tablets can lead not only to a burden for the patient, but also to deterioration of adherence. In some studies, it has been shown that adherence decreases with the number of pills a patient has to take. This means that with each additional pill, the patient’s adherence to therapy can decrease. Conversely, this means that reducing the number of tablets can improve a patient’s adherence.
Often, however, reducing the number of tablets is not possible from a medical point of view, since all prescribed medications are important for treating the patient’s conditions and cannot simply be omitted. But in some cases, several individual pills can be combined into a single pill. A study on hypertension, for example, has shown that simplified tablet use can result in easier therapy, increased adherence, and a reduction in the risk of secondary diseases (e.g. stroke, another heart attack, or cardiovascular death).
The following questions will help you find out if single pill therapy might be suitable for you:
How many pills do I take each day?
Am I taking my pills reliably and on time?
Do I feel burdened by the intake of my pills?
Currently, there is not yet the possibility of a single pill for all diseases and their therapy. However, many single pills are already available for diseases of the cardiovascular system and they are already being used in other areas of medicine as well. If you would like to learn more about the concept of single pill therapy, talk to your doctor about it. Your doctor can advise you on whether a single pill therapy approach would work for you.
In general, you should pay attention to your therapy and talk to your doctor if you have any questions or uncertainties.
If you are interested in learning more about a possible single pill therapy, contact your doctor. Talk to your doctor about your current drug therapy and the burden you feel from the intake of several pills. Ask your doctor if in your individual case it would be possible to replace two or even three medications with a fixed-dose combination tablet (single pill). To prepare for the conversation with the doctor, you can write down the questions you want to ask them. If you find it difficult to listen carefully to them and write down the answers to your questions at the same time, it may be helpful to take another person (for example your partner) with you to the doctor’s appointment.
It is important to remember that changes to medication should never be made without consulting your doctor. If you have the impression that you cannot tolerate a medication or are not experiencing the desired effect, please talk to your doctor about it.
If you would like advice about your medications in general, you can bring it up with your doctor at your next appointment. Another option is medication counseling at your pharmacy. Ask your pharmacy if they offer this service and make an appointment. Ask as well which documents (e.g. therapy plan, allergy card) should be brought to the consultation appointment.