The development of a smartphone app to enhance post-traumatic stress disorder treatment in high-risk workers.

Objective: Post-traumatic stress disorder (PTSD) is highly prevalent in certain populations. However, evidence indicates that many individuals do not respond to treatment. Digital supports hold promise for increasing service provision and engagement but there is a lack of evidence on blended care options and still less research guiding the development of such tools. This study details the development and overarching framework used to build a smartphone app to support PTSD treatment. Methods: The app was developed in line with the Integrate, Design, Assess, and Share (IDEAS) framework for the development of digital health interventions and involved clinicians (n=3), frontline worker clients (n=5) and trauma-exposed frontline workers (n=19). Integrated iterative rounds of testing were conducted via in-depth interviews, surveys, prototype testing and workshops, alongside app and content development. Results: Clinicians and frontline workers both expressed a clear preference for the app to augment but not replace face-to-face therapy, with the aim of increasing between-session support, and facilitating homework completion. Content was adapted for app delivery from manualised therapy (trauma-focused cognitive behavioural therapy (CBT). Prototype versions of the app were well received, with both clinicians and clients reporting the app was easy to use, understandable, appropriate and highly recommendable. System Usability Scale (SUS) scores were on average in the excellent range (82/100). Conclusions: This is one of the first studies to document the development of a blended care app designed specifically to augment clinical care for PTSD, and the first within a frontline worker population. Through a systematic framework with active end user consultation, a highly usable app was built to undergo subsequent evaluation.