0375 CHANGES IN EPWORTH SLEEPINESS SCALE DURING BEDTIME RESTRICTION THERAPY IN CO-MORBID INSOMNIA AND OBSTRUCTIVE SLEEP APNEA

Abstract Introduction: Co-morbid insomnia and sleep apnea (COMISA) is a highly prevalent and debilitating condition. Recommended treatment for COMISA includes initial treatment with Cognitive Behavioral Therapy for Insomnia (CBTi). Bedtime restriction therapy is an effective component of CBTi that involves temporarily reducing time spent in bed to consolidate sleep periods and decrease pre-sleep hyperarousal. However bedtime restriction also temporarily increases daytime sleepiness. As sleep apnea is commonly associated with increased sleepiness at baseline, it is important to monitor the effect of bedtime restriction therapy in COMISA patients during CBTi to avoid potentially dangerous excessive daytime sleepiness. Methods: 72 patients with co-morbid insomnia (ICSD-2) and sleep apnea (AHI ≥ 15) who were participating in a randomized controlled trial completed 7-day sleep diaries, and Epworth Sleepiness Scales at baseline, during 4-weekly sessions of CBTi, and at post-treatment. Paired t-tests were used to compare differences in average sleep parameters and sleepiness between baseline and each week of treatment. Results: Epworth Sleepiness Scale scores did not increase significantly during any week of CBTi compared to baseline. Instead they showed a small significant reduction by week-4 (2 point reduction, p≤0.001) and post-treatment (1.5 point reduction, p≤0.001) compared to baseline. Subjective total sleep time showed a 30 minute decrease by the second CBTi session (p≤0.001), but was significantly greater than baseline by week-4 (15 minute increase, p≤0.01) and post-treatment (25 minute increase, p≤0.001). Finally, sleep efficiency scores were significantly increased compared to baseline at week-2, week-3, week-4 and post-treatment (10–18 percent increase from baseline, all p≤0.001). Conclusion: Bedtime restriction therapy did not lead to increased levels of subjective sleepiness during CBTi in patients with COMISA. In fact, by the fourth week of CBTi, sleepiness scores were significantly lower than at baseline. This decrease in subjective sleepiness was accompanied by increased total sleep time and sleep efficiency throughout treatment. These data suggest that CBTi is a safe and effective treatment in patients with COMISA. Support (If Any): This research was made possible by an on-going National Health and Medical Research Council-funded grant examining different treatment options in patients with co-morbid insomnia and sleep apnea (nhmrc 104959).