Introduction
Asthma is a serious global health problem. People of all ages in countries throughout the world are affected by this chronic airway disorder that, when uncontrolled, can place severe limits on daily life and is sometimes fatal. The prevalence of asthma is increasing in most countries, especially among children. Asthma is a significant burden, not only in terms of health care costs but also of lost productivity and reduced participation in family life. [1]
Asthma is characterized by an inflammation in airways. This inflammation has many consequences like wheezing, breathlessness, chest tightness, and coughing. This chronic disease appears to be increasing more in younger than in older children (“Using the Health Services Central Administration data base we reviewed 24271 admissions and saw that 48.7% of patients admitted were aged under 19 years-old” [2]). They are more exposed to the disease due to their fragile immune system, and that's why the disease control on this population is crucial. [1] [3]
From the GINA guidelines: Asthma control refers to control of the clinical manifestations of disease. A working scheme based on current opinion that has not been validated provides the characteristics of controlled, partly controlled and uncontrolled asthma. These three categories are explained in the table presented in appendix 5. Complete control of asthma is commonly achieved with treatment, the aim of which should be to achieve and maintain control for prolonged periods, with due regard to the safety of treatment, potential for adverse effects, and the cost of treatment required to achieve this goal.[1]
In children, asthma control can be assessed using questionnaires, such as the Childhood Asthma Control Test (C-ACT). A cross-sectional validation was conducted and the results were a score of 19, which indicated inadequately controlled asthma in children between the ages of 4 and 11 years old.[4]
Controlled children have minimal effects of asthma, while children who are not controlled present more complications , and if no action is taken quickly, when the therapy is actually started it will certainly be more difficult to diminish the symptoms and control the disease. [5]
Furthermore, this disease causes instability on family life of asthmatic children, rising the costs and affecting the family environment. The control of asthma thus gains the necessity to be applied all over the world, being particular for each country and its reality, but obeying to 
international rules. This way, the fight against asthma should and can be improved and unnecessary deaths can be prevented.
Knowing the percentage of controlled children (aged between 0 and 18 years old) is essential to understand the need to inform and help people to control the disease. That was our motivation to choose the following question: “What is the prevalence of asthma control in children in Europe?”.