Association Between the Morisky Medication Adherence Scale and Medication Complexity and Patient Prescription Knowledge in Primary Health Care

The aim of the study was to check the association of the Morisky Medication Adherence Scale with the prescription complexity and with the patient's level of knowledge about the prescription. A cross-sectional study was conducted by means of an interview and analysis of the prescription received by patients selected at Family Health Strategy Units. A Poisson regression model with robust variance was used to describe the association between the variables. Low adherence was significantly associated with highly complex prescriptions: Prevalence Ratio (PR) = 133; 95 % Confidence Interval (CI) = 1.28-1.82, in comparison with low and moderate complexity. Low adherence was also significantly associated with very low levels of knowledge: regarding the highest level (third tertile), the first and second tertiles had PR = 4.44; 95 % CI = 3.26-6.06 and PR = 3.22; 95 % CI = 2.33-4.47, respectively. The Morisky scale is useful to measure low adherence, with the advantage of being an easily understood instrument, which can be quickly administered, presenting simple interpretation and application.