This study is intended to extend the knowledge of Symbicort Single Inhaler Therapy into a more general setting in order to assess the real-life impact of introducing this new treatment concept. The study will compare the Symbicort Single Inhaler Therapy concept with a conventional stepwise treatment regimen according to the investigator's judgement in patients who present with symptoms on inhaled glucocorticosteroids (GCS) treatment or who require and are already on treatment with a combination of inhaled and long-acting B2 agonists (LABA).