Efficacy of Mobile App-Based Cognitive Behavioral Therapy for Insomnia: Multicenter, Single-Blind Randomized Clinical Trial

Abstract

Background: Cognitive behavioral therapy for insomnia (CBTi) is the first-line therapy for chronic insomnia. Mobile app-based CBTi (MCBTi) can enhance the accessibility of CBTi treatment; however, few studies have evaluated the effectiveness of MCBTi using a multicenter, randomized controlled trial design.

Objective: We aimed to assess the efficacy of Somzz, an MCBTi that provides real-time and tailored feedback to users, through comparison with an active comparator app.

Methods: In our multicenter, single-blind randomized controlled trial study, participants were recruited from 3 university hospitals and randomized into a Somzz group and a sleep hygiene education (SHE) group at a 1:1 ratio. The intervention included 6 sessions for 6 weeks, with follow-up visits over a 4-month period. The Somzz group received audiovisual sleep education, guidance on relaxation therapy, and real-time feedback on sleep behavior. The primary outcome was the Insomnia Severity Index score, and secondary outcomes included sleep diary measures and mental health self-reports. We analyzed the outcomes based on the intention-to-treat principle.

Results: A total of 98 participants were randomized into the Somzz (n=49, 50%) and SHE (n=49, 50%) groups. Insomnia Severity Index scores for the Somzz group were significantly lower at the postintervention time point (9.0 vs 12.8; t₉₅=3.85; F_2,95=22.76; η_p²=0.13; P<.001) and at the 3-month follow-up visit (11.3 vs 14.7; t₆₈=2.61; F_2,68=5.85; η_p²=0.03; P=.01) compared to those of the SHE group. The Somzz group maintained their treatment effect at the postintervention time point and follow-ups, with a moderate to large effect size (Cohen d=-0.62 to -1.35; P<.01 in all cases). Furthermore, the Somzz group showed better sleep efficiency (t₉₅=-3.32; F_2,91=69.87; η_p²=0.41; P=.001), wake after sleep onset (t₉₅=2.55; F_2,91=51.81; η_p²=0.36; P=.01), satisfaction (t₉₅=-2.05; F_2,91=26.63; η_p²=0.20; P=.04) related to sleep, and mental health outcomes, including depression (t₉₅=2.11; F_2,94=29.64; η_p²=0.21; P=.04) and quality of life (t₉₅=-3.13; F_2,94=54.20; η_p²=0.33; P=.002), compared to the SHE group after the intervention. The attrition rate in the Somzz group was 12% (6/49).

Conclusions: Somzz outperformed SHE in improving insomnia, mental health, and quality of life. The MCBTi can be a highly accessible, time-efficient, and effective treatment option for chronic insomnia, with high compliance.

Trial registration: Clinical Research Information Service (CRiS) KCT0007292; https://cris.nih.go.kr/cris/search/detailSearch.do?seq=22214&search_page=L.

Keywords: cognitive behavioral therapy; digital therapeutics; insomnia; mental health; mobile app–based cognitive behavioral therapy for insomnia; mobile phone.

Figure 1

Example screenshots of the Somzz app.

Figure 2

Flowchart of participant enrollment. SHE: sleep hygiene education.

Figure 3

Insomnia Severity Index (ISI) scores at each time point. (A) Between-group comparison of ISI scores at each time point (analysis of covariance). (B) Within-group analysis of ISI scores at each clinical visit compared with baseline scores (2-tailed paired t test). The numbers on the bar graphs are Cohen d values. Error bars are also presented. In the Somzz and sleep hygiene education (SHE) groups, 69% (34/49) and 76% (37/49) of the participants, respectively, consented to take part in the 4-month follow-up. The postintervention time point was 6 to 9 weeks after the baseline. *P<.05; **P<.01; ***P<.001.

Figure 4

Comparison of sleep efficiency via sleep diary measures between the Somzz and sleep hygiene education (SHE) groups. Group comparison of Insomnia Severity Index scores at each time point using analysis of covariance adjusting for the baseline score. *P<.05; **P<.01; ***P<.001.