Evaluation of methods measuring medication adherence in patients with polypharmacy: a longitudinal and patient perspective

To explore patients’ willingness to have medication adherence measured using different methods and evaluate the feasibility and validity of their combination (i.e., pill counts, a medication diary and a questionnaire assessing adherence two months post-discharge). (1) A cross-sectional evaluation of the willingness of patients with polypharmacy to have their medication adherence measured post-discharge. (2) Medication adherence was monitored during two months using pill counts based on preserved medication packages and a diary in which patients registered their adherence-related problems. During a home visit, the Probabilistic Medication Adherence Scale (ProMAS) and a questionnaire on feasibility were administered. A total of 144 participants completed the questionnaire at discharge. The majority was willing to communicate truthfully about their adherence (97