The use of discrete choice experiments in adherence research: A new solution to an old problem

Theory can play an important role in providing the framework, and underpinning the design and implementation of interventions to improve medication adherence. Interventions that are grounded in a theory are relatively more effective in improving medication adherence than interventions which do not have a theoretical support. However, a large body of adherence research does not appear to be linked to any theory or model, which therefore may have resulted in interventions that are either ineffective or not sustainable. Interventions that are based on theory have mainly employed socio-behavioural models to explain, and design interventions to address, the complex phenomenon of adherence. Yet, the effectiveness of these interventions is inconclusive, supporting the argument that socio-behavioural models alone have limited applicability in explaining behaviour associated with medication-taking. An important reason for this limitation may be the complex and dynamic nature of adherence. There is a need to include a wide variety of factors in a model and examine adherence in the context of its three phases (initiation, implementation, and discontinuation). One possible way forward is to also examine medication-taking behaviour from an economic perspective, for example, by using a discrete choice experiment (DCE), which provides a different approach to understanding human behaviour about medication-taking and the complexities of decision-making in adhering to medication. DCEs can help in understanding how patients decide to initiate, continue or discontinue taking medication, factors that influence their decision, and the relative importance of those factors, which can assist researchers to prioritise interventions to improve medication adherence. Integration of multiple theories is needed to examine adherence from multiple perspectives and design interventions that are effective and sustainable. This commentary focusses on the pros and cons of some of the commonly used socio-behavioural models in adherence research and suggests a way forward by incorporating DCEs in adherence research.