ABSTRACT
I. Introduction Both short-acting and long-acting bronchodilators have been used for many years for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Patient response to these agents is characterized by a large degree of heterogeneity due in part to genetic variability and differences in disease severity. Furthermore, initiation of guideline-based treatment is often poorly applied in developed countries because of lack of awareness and in developing countries because of cost or cultural preferences. Increasing emphasis is placed on “asthma control,” that is, the extent to which the manifestations of asthma have been reduced or removed by treatment (1). Its assessment should incorporate the dual components of current clinical control (i.e., symptoms, reliever use, and lung function) and future risk (e.g., exacerbations and lung function decline). The most clinically useful concept of severity is based on the intensity of treatment required to achieve good control, that is, severity is assessed during treatment. For example, severe asthma requires high-intensity treatment. Severity may be influenced by underlying disease activity and patient phenotype (1).
