Adherence to treatment of hypertension, hypercholesterolaemia and diabetes in an elderly population of a Spanish cohort

Background and objective: Sub-optimal adherence to treatment in the general population has been highlighted in several studies, especially in the elderly and/or chronic patients. This study aims to describe the adherence to treatment of diabetes mellitus, dyslipidaemia and hypertension, and to identify the factors that influence adherence. Material and method: Retrospective, cross-sectional observational study on 16,208 patients aged >= 65 years from the EpiChron Cohort who initiated monotherapy treatment of an antidiabetic, a lipid lowering or an antihypertensive medication in 2010. Adherence was measured by calculating the medication possession ratio during one year, considering those cases with medication possession ratio >= 80% to be adherent. We performed a descriptive study, and a logistic regression model was used to identify the predictors of low adherence. Results: Adherence to antidiabetics, antihypertensive and lipid-lowering drugs was 72.4%, 50.7% and 44.3%, respectively. An increase in adherence of 3-8% was observed for each additional chronic disease suffered by the patient. The presence of mental illness did not affect adherence, and sex, age and number of prescribed drugs did not present consistent effects. Conclusion: The results obtained show a sub-optimal adherence to treatment for the 3 chronic diseases studied. Adherence increased with the number of chronic diseases, while sex, age and number of drugs did not show a consistent effect. It is necessary to investigate if there are other factors that may influence therapeutic adherence, since improving adherence may have a greater impact on health than any progress in therapies. (C) 2018 Elsevier Espana, S.L.U. All rights reserved.