[Treatment adherence: a key element]

A substantial percentage of patients fail to follow health professionals' recommendations, which affects the management of chronic diseases, reducing the effectiveness of therapeutic interventions and increasing the costs of the disease. Lack of adherence is a multidimensional phenomenon and is influenced by numerous factors that should be identified. A multiplicity of measures is available to improve adherence, such as simplifying treatment administration, but none of these measures is effective when used alone. One way of tackling lack of adherence is by identifying patients' barriers to medication and involving them in decision making. Ulcerative colitis (UC) poses a risk for lack of treatment adherence. In this disease, poor adherence correlates with poor disease control (drug effectiveness) and with higher costs. As in other chronic diseases, the causes associated with poor adherence are multiple, including psychosocial factors, the physician-patient relationship and patients' prejudices toward medication. A single dose of aminosalycylates (5-ASA) should be recommended, as this dose is as safe and effective as other regimens. However, by itself, this recommendation does not seem to improve adherence. Identifying the scale of the problem and developing strategies to involve the patient in decision making is crucial to improve treatment adherence.