P110 Does better adherence to Sleep Restriction Therapy produce a faster clinical response in CBT-I?

Abstract Introduction Sleep Restriction Therapy (SRT) is a key component of CBT-I. The goal of SRT is to build sleep debt to consolidate sleep and increase sleep efficiency. Given that, one would expect greater adherence to SRT to predict a faster clinical response, defined as fewer weeks of restriction prior to the first increase in time-in-bed (once 85% sleep efficiency is reached). Here, we examined this hypothesis for the first time. Methods 83 participants were randomized to 7 weeks of therapist-led CBT-I. 78 initiated SRT (age: 48.0±14.3, 57.7% F). A Poisson regression was conducted to investigate the relationship between adherence to SRT (deviation from bed and wake times, naps) and the number of weeks in SRT prior to the first increase in time-in-bed. Age and diary-based sleep efficiency in week 1 (prior to beginning SRT) were added to the model as covariates. Results There was a significant positive association between waking later than prescribed wake time and number of weeks in SRT prior to increasing time-in-bed (p <.05). However, deviation from prescribed bedtime and napping were not significantly associated with time in SRT. Conclusion Overall, better adherence to morning wake time is associated with faster response to SRT. Adhering to morning wake time may further promote sleep deprivation and stabilise circadian rhythms, thereby improving the sleep efficiency required to increase time-in-bed. Given the challenging nature of SRT, a relationship between adhering to wake time and faster titration upward of time-in-bed may improve both therapist treatment fidelity and client motivation.