Factors associated with adherence to cardioprotective drugs in patients with acute myocardial infarction in primary health care

Abstract Introduction The use of cardioprotective medications after acute myocardial infarction allows for better outcomes in reducing mortality and recurrence of thrombotic events. Medication adherence, defined as the process by which patients take their medications as prescribed, is the subject of study in these patients, highlighting difficulties in adhering to these classes of medications. Objective The objective of this study is to evaluate the relationship between medication adherence, the number of medications prescribed, and the variables age, sex, education, and income. Furthermore, it seeks to identify the overall rate of adherence to cardioprotective medications by prescribed dose and care. Methods The study was approved by the research ethics committee. Data were collected in primary health care units, including patients over 18 years of age with a history of myocardial infarction who self-manage their cardioprotective medications. Validated instruments for sociodemographic characterization and self-reported adherence (Specialty Global Medication Adherence Assessment) were used for data collection. Comparisons between adherent and non-adherent participants regarding quantitative variables were performed using the Mann-Whitney test, with data distribution assessed by the Shapiro-Wilk test. Pearson's chi-square test was applied to evaluate associations between qualitative variables. Results Sixty-four patients using cardioprotective medications were interviewed, the majority being male (60.9%), with a mean age of 67.1 years. The adherence rate based on prescribed dose was highest for beta-blockers (88.8%), ACE inhibitors (99%), angiotensin II receptor blockers (ARBs) (95%), statins (83%), and antiplatelet agents (91%). Adequate care was observed among ACE inhibitor users (78.9%), while ARBs showed the lowest proportion (66.7%). The overall classification considering (adequate dose and care) was 50% for this study. Regarding the comparison test, there was no statistically significant difference or association between the number of doses prescribed and adherence. Regarding the gender variable, women showed a statistically significant association with adherence, with a higher probability of adhering to treatment compared to men (p = 0.022). Conclusion Overall adherence to each cardioprotective agent, according to the prescribed dose, as well as the care taken when administering the medications, showed high adequacy rates (70%). However, when considering both pieces of information and all cardioprotective agents used by the patient, only 50% of participants followed the prescription exactly as they should. These findings suggest that the number of doses prescribed does not influence adherence; individual and behavioral characteristics play a central role in adherence to cardioprotective treatment and reinforce the need for targeted educational interventions, especially for groups with lower adherence or inadequate care.