ABSTRACT
BACKGROUND: Medication adherence is the extent to which patients take medications as prescribed by their health care providers. There are a number of approaches to study medication-taking behavior. The aim was to compare two most common methods for measuring adherence: Patient Adherence Questionnaire and Medication Possession Ratio (MPR). They belong to the indirect methods. METHODS: In this article four adherence studies were analysed and the results were compared, two wherein the patient questionnaire was applied and other two with medication possession ratio applied. RESULTS: The obtained results reveal that more than half of respondents (58.9%) experienced constant nonadherence behavior according to the prescribed therapy. The main reason of nonadherence is oblivion, suggesting that it is necessary to pay more attention to this problem. CONCLUSIONS: Nonadherence with therapy has negative consequences on the health of the individual, and an adverse impact on the community health and wealth. Patients should be informed of the importance of regularly taking prescribed therapy. The main problem of long-term therapy is significantly decreased of adherence to medication in a very short time. It is important to stress that almost all the interventions effective for improving patient adherence in long-term care are complex and should be repeated after a while.