This article outlines the development, testing and evaluation of an asthma patient passport (APP). The APP was designed specifically for patients with severe and difficult-to-manage asthma. This patient group tends not to access emergency services when needed, potentially putting life at risk. These individuals prefer to self-manage rather than expose themselves to feelings of vulnerability in the emergency department (ED). The aims of the project were to save lives by ensuring these patients attend the ED, to improve patient experience in the ED and to assist healthcare professionals in their clinical decision making, enabling them to deliver appropriate and individualised emergency treatment.