Many parents of infants with CHD find it difficult to recognise symptoms of deterioration in their children. Therefore, a personalised decision support application for parents has been developed. This application aims to increase parents’ awareness of their infant’s normal condition, help them assess signs of deterioration, decide who and when to contact health services, and what to report. The aim of this paper is to describe the concept and report results from a usability study.

An interprofessional group developed a mobile application called the Heart OBServation app in close collaboration with parents using an iterative process. We performed a usability study consisting of semi-structured interviews of 10 families at discharge and after one month and arranged two focus group interviews with nurses caring for these families. A thematic framework analysis of the interviews explored the usability of features in the application. Usability was assessed twice using the System Usability Scale, and a user log was registered throughout the study.

The overall system usability score, 82.3 after discharge and 81.7 after one month, indicates good system usability. The features of Heart OBServation were perceived as useful to provide tailored information, increase awareness of the child’s normal condition, and to guide parents in what to look for. To empower parents, an interactive discharge checklist was added.

The Heart OBServation demonstrated good usability and was well received by parents and nurses. Feasibility and benefits of this application in clinical practice will be investigated in further studies