Patients' Perceived Importance of Medication and Adherence in Polypharmacy, a Quantitative, Cross-Sectional Study...

Among the determinants of nonadherence, polypharmacy (common in people with multiple pathologies and especially in elderly patients), plays a major role.

In patients who are subject to polypharmacy involving different classes of medications, the first aim is to assess the impact of medication importance given by patients on (i) medication adherence and (ii) the respective effect of intentionality and habit in medication importance and medication adherence. The second objective is to compare the importance given to medication and adherence in the different therapeutic classes.

Patients taking 5-10 different medications for at least 1 month were included in a cross-sectional survey in three private practices in one region in France.

This study included 130 patients (59.2 % female) with 851 medications in total. The mean ± standard deviation (SD) age was 70.5 ± 12.2 years. The mean ± SD of medications taken was 6.9 ± 1.7. Treatment adherence had a strong positive correlation with the patient-perceived medication importance (p < 0.001). Counter-intuitively, taking a large number of medications (≥7) was associated with being fully adherent (p = 0.02). A high intentional nonadherence score was negatively associated with high medication importance (p = 0.003). Furthermore, patient-perceived medication importance was positively associated with taking treatment by habit (p = 0.03). Overall nonadherence more strongly correlated with unintentional nonadherence (p < 0.001) than with intentional nonadherence (p = 0.02). Compared to the antihypertensive class, a decrease in adherence by medication was observed in psychoanaleptics (p < 0.0001) and drugs used in diabetes class (p = 0.002), and a decrease in importance in lipid-modifying agents class (p = 0.001) and psychoanaleptics (p < 0.0001).

The perception of the importance of a medicine is associated with the place of intentionality and habit in patient adherence. Therefore, explaining the importance of a medicine should become an important part of patient education.