Adherence of polymedicated older adults: how do they behave regarding medication intake?

Abstract

Objective To analyze the association between medication therapy adherence and level of understanding and complexity of the prescription, as well as to assess the agreement between two adherence questionnaires administered to polymedicated older adults. Method This is a cross-sectional study involving older adults attending the geriatrics outpatient clinic at a university hospital in Rio de Janeiro, Brazil. In these patients, medication therapy adherence (assessed using the Brief Medication Questionnaire - BMQ and the Instrument for Assessing Attitudes Toward Medication Taking - IAAFTR), knowledge about prescribed medications, and pharmacotherapy complexity were evaluated. Statistical analysis was conducted using Chi-square tests and Fisher's Exact test, with a significance level set at p-value ≤ 0.05. The agreement between the two adherence methods was assessed using the Kappa index. Results Of the 49 interviewed older adults, 75.5% were women, with arterial hypertension (82%) and diabetes (37%) being the most prevalent conditions. According to the BMQ and IAAFTR tests, 35% and 45% of patients, respectively, were adherent to medication therapy. There was no agreement in the results between the adherence methods. A large proportion of patients exhibited a good level of information about their medications; however, the majority of them were considered non-adherent. No statistically significant association was observed between prescription complexity and adherence, nor between the level of medication information and adherence. Conclusion Medication therapy adherence is a multifactorial process, and the assessment tools for adherence and other influencing factors should be carefully chosen according to the study population, as they exhibited different responses in our work.