Abstract
Introduction
The prevalence of insomnia complaints in older adults is 30–48%, compared to 10–15% in the general population. Cognitive Behavioral Therapy for Insomnia (CBT-I) is a first-line, non-pharmacological sleep treatment for Insomnia. However, the relative impact of Behavioral (BT) and Cognitive (CT) components compared to that of CBT-I in older adults is unknown.
Methods
128 older adults with insomnia were randomized to receive CBT-I, BT, or CT. Sleep diaries and the Insomnia Severity Index (ISI) were collected pre- and post-treatment and at a 6-month follow-up. We conducted split-plot linear mixed models with age and sex as covariates to assess within and between subject changes to test effects of group, time, and their interaction on ISI, sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), time in bed (TIB), sleep efficiency (SE), and percent of treatment responders (ISI decrease>7) and remitters (ISI<8). Effect size (d) was calculated by dividing the difference between means by the root-mean-squared error of the mixed effects model.
Results
All treatments lead to a significant improvement across outcome measures at post-treatment (p’s<0.001) and 6-months (p’s<0.01), with the exception of TIB, response, and remission. For TIB, there was a significant Group x Time interaction (p<0.001): while all treatments significantly reduced TIB post-treatment relative to baseline, CBT-I (p<0.001,d=-2.26) and BT (p<0.001,d=-1.59) performed significantly better than CT (p=0.003, d=-0.68). In contrast, at 6-months CBT-I (p<0.001,d=-1.16) performed significantly better at reducing TIB than CT (p=0.195,d=-0.24) or BT (p=0.023,d=-0.61) relative to baseline. There was also a non-significant trend for a Group x Time interaction for remission status (p=0.062). Whereas, the percentage of remitters within all groups post-treatment did not differ from chance (p>0.234), at 6 months, the percentage of remitters was significantly higher than chance in CBT-I (73.63%,p=0.026) and BT (78.08%,p=0.012), but not CT (47.85%,p=0.826). There were no other significant time or interaction effects (all p>0.05).
Conclusion
CBT-I and its components are effective in improving subjective insomnia symptoms in older adults. Evidence suggests CBT-I may be superior to either CT or BT alone in improving TIB in older adults.
Support (if any)
NIMHR01MH101468; MIRECC at VAPAHCS
