Breakthrough Insights into Medication Adherence: Unpacking the MMAS-8’s Four Key Questions on Unintentional Non-Adherence

The 8-item Morisky Medication Adherence Scale (MMAS-8) has emerged as a gold standard for assessing adherence, offering a simple yet powerful tool to identify barriers. A key breakthrough in its application lies in pinpointing the four questions that specifically address unintentional non-adherence, such as forgetfulness, providing clinicians and researchers with actionable insights to improve patient care. In this blog, we explore these four questions, their significance, and how they’re reshaping our approach to medication adherence.

​Below are key findings from relevant articles:
• Cross-cultural adaptation and validation of a European Portuguese version of the 8-item Morisky Medication Adherence Scale (Revista Portuguesa de Cardiologia, 2018):
• This study tested a two-dimensional model of the MMAS-8, separating items into unintentional and intentional non-adherence subscales. Items 1, 4, and 8 were explicitly included in the unintentional non-adherence subscale, focusing on behaviors like forgetting to take medication or missing doses due to reasons other than intentional choice. The study reported a Cronbach’s alpha of 0.65 for the unintentional non-adherence subscale, indicating acceptable internal consistency for these items.
• Unintentional non-adherence to chronic prescription medications: How unintentional is it really? (PMC, 2012):
• This article analyzed unintentional non-adherence using data from the Harris Interactive Chronic Illness Panel, involving 24,017 adults. It identified items 1, and 8 of the MMAS-8 as directly assessing unintentional non-adherence behaviors, such as forgetting to take medication (reported by 62% of respondents), running out of medication (37%), and being careless (23%). While item 4 (travel-related forgetfulness) was not explicitly highlighted in this study, it aligns with unintentional behaviors discussed in other sources. The study emphasized that unintentional non-adherence may be influenced by underlying beliefs, suggesting a complex interplay with intentional non-adherence.
• Psychometric properties of the eight-item Morisky Medication Adherence Scale in a psychiatric outpatient setting (International Journal of Clinical and Health Psychology, 2014):
• This study described the MMAS-8 as a tool designed to capture both intentional and unintentional non-adherence. It noted that items addressing forgetfulness and logistical barriers (e.g., items 1, 4, and 8) are associated with unintentional non-adherence, such as forgetting to take medication or failing to bring it when traveling. The article highlighted the scale’s ability to identify barriers like forgetfulness in psychiatric patients