Adherence is a major concern for clinicians across all disciplines. Even the most effective treatment will not be successful if the patients does not adhere to the prescribed treatment strategy. Inside learn more about the problem and ways to maximize adherence.
Adherence rates in multiple sclerosis are slightly higher than those reported in other chronic diseases. The World Health Organization has estimated the average adherence rate in chronic disease to be 50%,[see PDF] whereas adherence rates in MS are consistently between 60% and 80%.
Adherence to disease-modifying treatments (DMTs) has been defined in several ways; unfortunately, there is no “gold standard” definition. Because of the different dosing regimens between the self-administered MS DMTs (ranging from a once weekly dose [Avonex] to a daily dose [Copaxone, Gilenya]), the preferred method of measuring adherence is as a proportion.
Patients are categorized on the basis of the missed dose ratio. This ration is the number of doses missed, divided by the number of prescribed doses, in a set period of time: ≥ 80% of doses = adherent; < 80% = non-adherent.
No single attribute has been identified as the most common cause of non-adherence. Interestingly, in one study, when patients were asked why they miss doses, over half stated that they simply forget to take their DMT. Following forgetfulness, people cited fatigue and adverse effects as common reasons for missing doses. Comorbid alcohol dependence, longer disease duration and mild disability have also been implicated.
Each of the DMTs has a different dosing schedule, so it’s actually quite challenging to compare adherence rates between products. A review attempted to clarify the differences between products and found that those with less frequent dosing schedules tended to have better adherence. A Novartis-funded study found that adherence to the oral therapy, Gilenya, was better than the injectable therapies, so route of administration may play a role as well.
The acronym SIMPLE, created by a research group in the US, is a general guideline to consider in order to prevent non-adherence:
Simplify drug regimen: for instance, reduce the frequency of a dosing regimen, or ensure that it suits a patient’s daily life.
Impart knowledge: educate patients about the disease and their DMTs; patient’s understanding of both positively correlates with adherence.
Modify patient beliefs: address patient’s expectations about adverse effects and effectiveness of DMTs.
Patient communication: enhancing physician/patient and physician/family communication as well as telephone or email reminders, can improve adherence.
Leave the bias: there is a belief that certain demographic characteristics are predictive of poor adherence, but the literature has shown that nonadherence can affect anyone, regardless of sex, age, education, or race.
Evaluate adherence: physicians infrequently discuss adherence, and tend to overestimate the adherence rates of their patients. It’s important to continually ask patients about how they’re adhering to their medication.
The vast majority of the adherence literature has focused on patient-related factors, such as demographic and clinical characteristics that are associated with non-adherence. Adherence is a larger issue that involves health systems and providers. To truly address the issue of nonadherence (especially in chronic disease like MS), we need a systemic approach that focuses on training health care providers, and enhancing the capacity of our health system to educate patients.