An overview of the common methods used to measure treatment adherence

Abstract

Background and aims. The success of a treatment depends on the effectiveness of the medication regimen, provided that patients take the medicines as prescribed. A low rate of adherence in chronic conditions is associated with poor outcome and decreased quality of life, which constitutes an additional burden for the healthcare systems. To correctly identify the dimension of this problem may be a challenge, as there are numerous methods, definitions, patient settings and factors, each with their specific roles. Our aim was to give an appropriate overview of the most common validated methods that can be used to identify non-adherent patients.
 Methods. This overview is based on an online search of PubMed database and includes the relevant articles in this field.
 Results. We included both direct and indirect methods for measuring treatment adherence and presented concise information that can help researchers and clinicians when choosing an appropriate method. Both subjective and objective methods have advantages and disadvantages that should be fully understood and taken into consideration.
 Conclusions. Choosing a simple, accurate and inexpensive method that can give supplementary information about the patterns, beliefs and barriers of adherence would be desirable. But because this perfect method to measure treatment adherence does not exist, the best solution seems to be the combined use of at least two methods.

Adherence to treatment for polycystic ovarian syndrome: A systematic review

“…A recent review suggests that at least two methods of measuring adherence should be included in every study as there is no "gold standard" method for measuring adherence. [29] Future studies of PCOS treatments should measure and report adherence to each treatment component to facilitate a better understanding of the role adherence may play in treatment effectiveness. Clinicians should consider whether adherence is reported when evaluating the reported outcomes of a particular treatment.…”

How the EMERGE guideline on medication adherence can improve the quality of clinical trials

“…However, it is easily censored by participants and only provides an aggregate summary of adherence between visit periods. It does not allow precise estimates of initiation, implementation or persistence …”

“…It does not allow precise estimates of initiation, implementation or persistence. 30,31 F I G U R E 1 Illustration of the process of medication adherence according to the ABC taxonomy 28 adapted to a clinical trial setting. The example is illustrating a twice-a-day dosing schedule…”

“…A great advantage of self‐report, which is often overlooked in the literature on adherence measurements, is that it is the only way to explore why a participant has acted in a certain way regarding treatment and/or trial protocol adherence . This approach can be helpful in determining reasons for nonadherence during initiation of therapy, implementation and ongoing persistence, providing valuable and timely insight to the drug development and study design team.…”

Development of a PATIENT-Medication Adherence Instrument (P-MAI) and a HEALTHCARE PROFESSIONAL-Medication Adherence Instrument (H-MAI) using the nominal group technique

“…All 48 studies only assessed medication adherence from the patient's perspective [10,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] except one study which only assessed from the HCP's perspective [28]. Previous literature has recommended that adherence to medications should be assessed by more than one method as it can offer more accurate and reliable information [59]. It is well known that patients tend to overestimate their adherence to medications when using selfreported medication adherence instruments for fear of reprimand from their HCP [60].…”