The Children's Hospital of Philadelphia's ambulatory network uses an electronic health record (EHR) to document clinical information. Using the EHR, a clinical decision support tool will be designed to help the primary care physician's in caring for children with asthma. The goal will be to improve the primary care physician's use of the national Institutes of Health guidelines for the best care for asthma. To study this EHR decision support tool, it will be introduced into 5 practices while 5 other practices will have the existing asthma care information. It will be determined whether the physicians in the practices with the decision support tool are better at following the asthma guidelines. If the decision support tool works...then it will be offered to others to use with their EHR systems.