(PS6-B37) Efficacy of Mobile App Based Cognitive Behavioral Therapy for Insomnia: A Systematic Review

            Cognitive Behavioral Therapy for Insomnia (CBTi) is an evidence-based treatment for the prevalent disorder of chronic insomnia. Though CBTi is considered the first line intervention, there is a shortage of CBTi trained clinicians.  Digital CBTi (dCBTi), particularly self-managed versions, expand availability and overcome salient barriers related to COVID-19 pandemic restrictions. Past reviews have indicated the efficacy of dCBTi but have been primarily limited to internet-based interventions. Given the high utilization of smart-phones and rapid proliferation of mobile apps, it is important to evaluate the efficacy research for CBTi mobile apps.  A search was conducted using PsycINFO, PubMed, Medline, Nursing and Allied Health Database and Google Scholar. Additionally, reference sections of dCBTi related reviews and identified studies were searched. Inclusion criteria were a) CBTi delivered via mobile app utilized in at least one treatment arm, b) intervention targeting sleep improvement, c) participants age 12 or older, d) data collected on at least one measure of sleep, and e) publication in a peer reviewed journal in English. A total of 126 abstracts were reviewed resulting in 30 articles identified for full review. Two authors reviewed each article with discrepancies resolved by discussion and consensus, resulting in 16 articles from a wide variety of countries and examining 11 different apps (5 publicly available). Six of the studies were randomized controlled trials (RCT). Given the greater flexibility and applicability to pandemic conditions, we focus this discussion on the 14 studies examining self-management apps. Five RCTs compared CBTi apps to patient education (2) or waitlist control (3) utilizing the Insomnia Severity Index (ISI) as a primary outcome measure. All five found the app superior to baseline at post-test and 3-6 months follow-up, with four finding superiority to the control condition at both time points. Four RCTs also utilized the Pittsburgh Sleep Quality Index (PSQI) finding the app superior to baseline at post-test and 3-6 months follow-up, with 3 finding superiority to control at each time point. Among the 9 non-RCT studies, 6 utilized the ISI with 5 finding superiority to baseline at post-test, and the remaining study revealing superiority at 42-day follow-up. Five utilized the PSQI with 4 finding the app superior to baseline at post-test. Studies utilizing sleep-diary or objective sleep measures (2 RCTs, 5 non-RCT) found mixed results. In conclusion, existing research shows consistent evidence of efficacy utilizing validated, well-established outcome measures, but mixed results across various sleep parameters. Although no study directly compared apps to internet based CBTi, across the 5 RCTs, the average ISI reduction compared to control (3 points) was somewhat lower than a recent internet CBTi review (5 points) but by follow-up was similar (3.5 and 3.99 points respectively) suggesting potential parity between app and internet delivered CBTi. Research limitations included diverse insomnia inclusion criteria, mostly small sample sizes, and variable treatment lengths. Recommendations for clinical application and future research will be discussed.