Are we truly measuring what we think we are with medication adherence questionnaires? This study challenges current validation procedures, asserting that standard psychometric tests often yield inconclusive results. Analyzing 121 validation procedures of medication adherence questionnaires, the research reveals significant variations in test outcomes, especially for "construct validity" and "internal consistency." The paper highlights that assessing medication non-adherence involves multiple, related constructs, each demanding a distinct measurement approach. It proposes a refinement of non-adherence constructs, distinguishing between the extent of missed doses, modifiable reasons for non-adherence, and unmodifiable factors. Ultimately, the research suggests tailoring validation procedures and statistical methods to specific constructs within medication adherence, enhancing the reliability and relevance of questionnaire assessments in pharmacy and medical practice. This promises more precise and actionable insights into medication-taking behavior.
Published in the _European Journal of Clinical Pharmacology_, this paper is highly relevant to the journal's focus on therapeutics and pharmacology. It addresses a key aspect of clinical practice – medication adherence – and critically evaluates the tools used to measure it. By proposing a refined approach to questionnaire validation, the paper contributes to improved methodologies within clinical pharmacology research, potentially influencing future studies and practices.