Measuring childhood asthma control

Abstract

Several studies have documented the benefits of good asthma control on a variety of outcomes that are important to patients and society, such as no restriction in lifestyle, better physical fitness and quality of life, reductions in asthma burden, health care resource use and lower risk of exacerbations, oral steroid use, hospitalizations, and death. Therefore the aims of asthma management focus on achieving andmaintaining good asthma control and reducing future risks. The problem with this strategy is that correct assessment of asthma control is not straightforward. Several studies have found that the assessment of control varies markedly among health care professionals, as well as patients. Generally, both physicians and patients tend to overestimate the level of asthma control, with a subsequent risk of undertreatment. In an attempt to facilitate correct asthma control assessment, several simple and easy-to-use composite asthma control scores have been developed. Most try to capture the level of control in a single numeric value, such as the Asthma Control Test (ACT) and Childhood Asthma Control Test (c-ACT). Because the various tests use the same outcomes (daytime and nighttime symptoms, limitation of activities, and use of rescue medication), it is not unexpected that the results of these tests correlate with each other and with the Global Initiative for Asthma (GINA) definition of asthma control to some extent. However, symptoms, limitations of activities, and use of rescue medication are not independent variables. Physical activity is one of the most important causes of symptoms and reliever use in children. Therefore many children with insufficiently controlled asthma avoid strenuous exercise. The result is fewer daytime symptoms, less rescue use, and apparently controlled asthma. This is achieved at the expense of poorer fitness and a higher risk of obesity. Many parents (and children) are unaware of such changes in lifestyle. The question remains whether the various retrospectively collected tests capture the same information as the prospective but more cumbersome diary recordings and also whether a single cutoff value is sufficient or optimal in distinguishing between controlled and uncontrolled asthma. The study by Voorend-van