0437 The Effects of a 6-week Single-blind Online CBT-I Program on Daily Subjective and Objective Sleep Parameters

Abstract Introduction Insomnia exerts a substantial impact on a considerable portion of the population, resulting in significant detriments to health, workplace safety, and overall quality of life. Digital treatment programs have currently made effective and easily accessible treatment options possible. In our current study, we examine the impact of a 6-week single-blind digital CBT-I program by daily tracking sleep quality, duration, and fragmentation, subjectively and objectively. Tracking sleep objectively was made possible using an innovative sleep staging method founded on heartbeat variability and machine learning, enabling access to daily sleep macrostructure (i.e., a hypnogram). Methods Fifty-six participants with self-reported sleep problems were randomly assigned to either a control or an experimental group. Both groups used a mobile smartphone application daily to provide subjective reports and track their sleep using a heart-rate wearable (H10, POLAR®) over the course of 6 consecutive weeks. Only the experimental group completed the sleep training program (e.g., included educational videos, relaxation exercises, and cognitive training). We examined changes in subjective and objective sleep parameters using mixed Analysis of Variance with the factors Group (Control, Experimental) and Time (Beginning, End). We also analysed significant interactions with paired samples t-tests. Spearman correlations were used to examine the changes in daily sleep parameters over time. Results Only the experimental group showed higher subjective sleep quality (t=-3.8, p<.001) and shorter sleep onset latency (t=3.1, p=.006) at the end of the program. Among the objective sleep parameters, we found a small but statistically significant increase in the amount of deep sleep (t(25)=-2.93, p=.007), while the number of awakenings (t(25)=2.21, p=.03) and the number of sleep stages (t(25)=2.17, p=.04) showed a significant decrease from the beginning to the end of the sleep training. Conclusion The results reported in the current study indicate significant improvements in subjective sleep parameters and objective sleep parameters throughout a digital CBT-I sleep training program. When assessing the effects of digital interventions, it is important to consider daily and long-term objective sleep-related parameters. Support (if any) We would like to express our gratitude to the Doctoral College 'Imaging the Mind' for their financial support (FWF, Austrian Science Fund: W 1233-B).