Compliance (medicine)

In medicine, compliance or adherence refers to the fact that a patient follows the advice of the doctor, and takes the prescribed drugs in the quantities prescribed. Compliance is important for the treatment of chronic diseases.
Worldwide, non-compliance is a major obstacle to the effective delivery of health care. In 2003, the World Health Organization estimated that only about half the patients with chronic diseases living in developed countries follow treatment recommendations. In particular, low rates of adherence to therapies for asthma, diabetes, and hypertension are thought to contribute substantially to the human and economic burden of those conditions. Compliance rates may be overestimated in the medical literature, as compliance is often high in the setting of a formal clinical trial but drops off in a "real-world" setting.
Some drugs are difficult to take, because they must be taken at a specific time or interval; sometimes, several drugs must be taken together. This is seen as a major obstacle to compliance. Other factors that may adversely influence compliance are that many patients do not understand the benefits of being treated, or they see side-effects that they were not told about, the drugs costing a lot of money, poor communication or lack of trust between the patient and their health-care provider. Efforts to improve compliance have been aimed at simplifying drug packaging, providing effective medication reminders, improving patient education, and limiting the number of medications prescribed at the same time.