Validation of Rules of Two™ as a paradigm for assessing asthma control.

Assessing asthma control at each patient encounter is an essential task to determine pharmacologic requirements. Rules of Two (Ro2) was created from the original 1991 National Asthma Education Program guidelines to determine the need for controller therapy. This study determined the degree of agreement between Ro2 and the Expert Panel Report (EPR-3) definition of "in control" asthma and compared that value with the Asthma Control Test (ACT) in a group of asthmatics for the purpose of validating this tool.