The different elements of medication adherence

Hypertension is highly prevalent and one of the major risk factors for cardiovascular disease. Over 42% of the Portuguese adults would have hypertension. Even though the benefits of antihypertensive drugs have been extensively demonstrated, the control of hypertension continues to be inadequate. One major (and modifiable) reason is the fact that patients often do not only fail to take their medication as has been prescribed, but also fail to use it for a long uninterrupted period of time. A substantially poorer medication adherence rate is observed when analysing newly diagnosed patients, and accounting for those who fail to initiate treatment, fail to ever refill, and time after discontinue, rather than the more commonplace approach of only observing ongoing users. Conventional adherence measures therefore systematically underestimate the public health burden of non-adherence. In this book, we analyze adherence to antihypertensive therapy as a time-changing process with different risk factors for non-adherence over time. Low adherence rates, in all its elements, contributes greatly to the burden of mortalidy and morbility from cardiovascular disease in Portugal.