The aim of this non-interventional study is to ensure that patients in routine clinical practice follow given treatment instructions and to evaluate the number of reliever inhalations as well as the number of patient/days with more than 8/12 total inhalations at any day. If the number of reliever inhalations and thus the received inhaled glucocorticosteroid dose is not excessive, the safety conclusions from the clinical studies can be extrapolated to real life for better acceptance of SMART (Symbicort Maintenance and Reliever Therapy).

Inclusion Criteria:

• Persistent asthma
• Prior Symbicort Turbuhaler maintenance and reliever therapy in a single inhaler