Background: Asthma is the most common chronic disease among Danish children. The role of the health care professional is to evaluate the current level of asthma control (based on symptoms and lung function) and then adjust asthma treatment to gain and maintain control of the disease and ensure few or no symptoms. Successful asthma management involves guideline-based treatment and regular follow-up. In the present population-based intervention study, we have aimed to regionally implement the international guidelines from "Global Initiative for Asthma" (GINA) as a clinical pathway at a large Danish hospital (Viborg Hospital) and at all affiliated general practitioners (GP´s). Our hypothesis is that it can improve intersectional collaboration between health care professionals treating children with asthma based on a shared responsibility of the treatment called Shared Care. Aim: We aim to examine in 4 observational studies if implementation of clinical pathways and shared care lead to improvement of the following outcomes: Study 1) An increased proportion of asthmatic children followed at the right place, i.e. the well-controlled asthmatic children should be followed in general practice and children with uncontrolled asthma should be followed at the pediatrics department. Study 2) An increased overall proportion of children with well-controlled asthma. Study 3) Favorable changes in the use of asthma medication. Study 4) Self-reported higher quality of life among children with asthma Material and methods: Observational follow-up study from 1st of April 2011 to 31th of April 2014 to study the effect of implementation of a clinical pathway for the treatment of children with asthma. We have included 1540 children aged 0-15 years with a physician-validated asthma diagnosis who are followed either at a hospital specialist out-patient clinic at the pediatrics department at Viborg hospital or at one of 100 GPs in the Viborg area. At baseline the involved health care professionals participated in an introduction to the clinical pathway and treatment guide. Furthermore the clinical pathway and treatment guide are accessible on a website. Perspectives: This project may provide documentation for an effective asthma quality improvement intervention, which could be used nationally in the future organization of childhood asthma diagnosis, treatment and control. Acknowledgments: This project is supported by Folkesundhed i Midten. We sincerely thank Lars G. Hansen (Head of Department of Pediatrics, Viborg Hospital) for his help and participation.