Objectives: The E Sibling Project aims to address the needs of siblings of individuals affected by psychosis through provision of a comprehensive online intervention. The online intervention comprises four core elements, including: information on psychosis; various coping and promoting well-being strategies; siblings' blogs and discussion forum with peers; and an “Ask the Experts” function. After the intervention-prototype was developed, we tested its feasibility, usability and acceptability by siblings.

Methods: We evaluated the usability of the intervention-prototype using a non-randomised usability study with siblings of individuals diagnosed with psychosis. The usability study adapted Poulson et al's framework to collect subjective feedback from participants on ease of use, perceived usefulness and acceptability, together with objective usage data on the intervention.

Results: Twenty siblings were recruited to the usability test; 19 tried out the resource-prototype over a 4-week period and 17 completed the online evaluation after using the intervention. In total, 906 page-views were made by the participants and each spent about two hours using the resource. Participants evaluated the intervention as helpful, relevant and useful in terms of content, design and usability. Developments are needed to improve the navigation and intuitiveness of the resource.

Conclusions: Using an internet-based information-giving and peer support intervention to promote wellbeing and coping is feasible and acceptable to siblings of people with psychosis.