Factors influencing the adherence to Bright Light Therapy in youths with insomnia and eveningness: A mixed-methods study

Forrest Tin Wai Cheung, Ngan Yin Chan, Joey Wing Yan Chan, Winifred Tsz Yu Wong, Michelle Pui Yan Lee, Hao Fong Sit, Rachel Ran Wang, Jihui Zhang, Albert Martin Li, Colin A. Espie, Michael Gradisar, Yun-Kwok Wing, Shirley Xin Li

Abstract

Introduction Bright light therapy (BLT) has increasingly been used as a chronotherapeutic intervention for sleep and circadian problems. Previous research has raised concerns about non-adherence to BLT due to the behavioural commitment required, which could lead to less optimal treatment outcomes. Nonetheless, there has been limited research to examine BLT adherence in the youth population. This study used a mixed-methods approach to explore the factors related to BLT adherence.

Materials and Methods Seventy-five youths (mean age = 20.1±2.0, 54.7% female) with insomnia and eveningness underwent six-week group-based cognitive behavioural therapy for insomnia with adjunctive BLT (either active BLT (CBTI+BLT): n = 38, or placebo BLT (CBTI-BLT: n = 37)). BLT was delivered using a portable light device (Re-timerTM), and participants were instructed to use it for 30 minutes each morning immediately after waking up for five consecutive weeks with gradual timing advance. Daily diaries were used to measure self-reported light device use. Adherence was calculated as a percentage of the number of days used out of the total number of days prescribed (7 days x 5 weeks = 35 days). All participants completed a baseline assessment of their motivation for treatment. Post-treatment assessments included treatment creditability and expectancy, as well as a single-item measure of the perceived helpfulness of light therapy. These factors were used to predict BLT adherence using univariate linear regression analysis. A subset of participants (n = 20, mean age = 19.4±3.3, 60.0% female) were additionally invited to partake in a one-to-one semi-structured interview via video conferencing after completing the intervention to explore factors associated with their motivation and barriers for adherence to BLT. All interviews were audio-recorded and transcribed verbatim. The contents of the interviews were analysed using a qualitative thematic analysis approach.

Results The overall adherence rate to BLT was 51.7% (95%CI (43.1, 60.2)) for the CBTI+BLT group and 54.0% (95%CI (46.6, 61.4)) for the CBTI-BLT group (p = .68). Only the perceived helpfulness of light therapy significantly predicted BLT adherence (β = .361, p = .004). Thematic analysis indicated that almost all participants (18/20) were motivated by either the potential (11/20) or perceived benefits (7/20) of using BLT during treatment. However, participants also reported practical constraints, including a lack of time in the mornings (20/20) and discomfort from using the device (13/20, e.g., the device is bulky and often slides down) that hindered continuous adherence to BLT. Lastly, participants indicated that they would be more willing to adhere to the prescription if they were given more psychoeducation on its benefit and if incorporating supervision and monitoring (e.g., daily report on online messengers) from the clinicians during treatment.

Conclusion The adherence rate to BLT in the current trial was suboptimal. Both quantitative and qualitative analyses showed that patients’ perceived benefits of BLT could best motivate their adherence to therapy. The findings from this study may inform future clinical practices of employing light therapy and suggest the need to consider strategies to provide psychoeducation on the benefits of BLT and monitor patients’ use of BLT with timely feedback.

Recommended citation: Cheung, F. T. W., Chan, N. Y., Chan, J. W. Y., Wong, W. T. Y., Lee, M. P. Y., Sit, H. F., ... & Li, S. X. (2024). Factors influencing the adherence to Bright Light Therapy in youths with insomnia and eveningness: a mixed-methods study. Sleep Medicine, 115, S55-S56.
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