MINNEAPOLIS – Both cognitive behavioral therapy for insomnia and mindfulness-based stress reduction training lessened insomnia in a group of cancer survivors, although the former works faster, new data show.
Investigators compared the two therapies head to head in I-CAN SLEEP (A Comparison of MBSR and CBT for the Treatment of Insomnia in Cancer), a randomized, partially blinded noninferiority trial among 111 adult patients from a tertiary care center in Calgary, Alta., who had nonmetastatic cancer and were at least 1 month out from completion of treatment. The behavioral therapies lasted 8 weeks.
At the end of the behavioral therapy, mindfulness-based stress reduction (MBSR) was inferior to cognitive behavioral therapy for insomnia (CBT-I) in terms of the difference in Insomnia Severity Index. But at 3 months, MBSR met the noninferiority criterion, with the 3.47-point upper bound of the confidence interval for the difference between groups falling within the predefined 4-point threshold (P = .01), Sheila N. Garland, Ph.D., reported at the annual meeting of the Associated Professional Sleep Societies. The data were recently published (J. Clin. Oncol. 2014;32:449-57).
Also at 3 months, diary data showed that sleep-onset latency had fallen from baseline by 14 minutes with MBSR and 22 minutes with CBT-I. The groups had a similar reduction in wake after sleep onset of about 35 minutes. Total sleep time increased by 0.73 hours with MBSR and 0.60 hours with CBT-I. Sleep efficiency improved by approximately 8% and 12%. And both therapies achieved a significant reduction in stress and mood disturbance.
"We confirmed that CBT-I produces faster effects and durable effects [when compared with] MBSR, but at 3 months, the two treatments are somewhat comparable and MBSR was not inferior according to our definition," said Dr. Garland of the department of family medicine and community health, University of Pennsylvania, Philadelphia.
"Both treatments were demonstrated to be effective for reducing symptoms of stress and mood disturbance, but I do believe that longer-term follow-up and comparisons are necessary because where CBT-I might be easy to grasp within, say, a 4-week period, mindfulness-based techniques are going to maybe take a little bit longer to incorporate into someone’s life and maybe apply to their sleep. So perhaps more practice is needed before we actually see longer effects."
Importantly, the rate of loss to follow-up at 3 months was 15% with CBT-I but a dramatic 50% with MBSR, with most of this dropout occurring within the first three sessions, noted Dr. Garland. She attributed the latter to the fact that patients were not aware of the specific treatments that were being compared when they agreed to participate in the study, which might have prevented dropout if they did not receive their preferred treatment.
"I actually believe that the blinding may underestimate clinical effectiveness, and this is because these people wouldn’t have normally chosen to practice mindfulness meditation, and that’s an important thing to note in terms of delivering behavioral interventions: people have to be willing, they have to buy into the intervention. So that’s what I think actually contributed to the large dropout," she elaborated. "You would see probably better improvement if they actually chose to go to that intervention. So my intention to blind participants to prevent that preferential dropout ... Well, these results say they are going to drop out anyway.
"This suggests that we should not apply a ‘one-size-fits-all model’ to the treatment of insomnia and emphasizes the need to individualize treatment based on patient characteristics and preferences," she added in an interview.
Session cochair Colin Espie, Ph.D., D.Sc., a professor of sleep medicine in the Nuffield department of clinical neuroscience at the University of Oxford (England), commented, "I think it’s really good to see other treatments being used, particularly in comorbid populations because clearly for people with cancer, sleep is occurring in a particular context and there may be advantages of a mindful approach to your situation in general, of which sleep is a part."
"But I thought there were maybe some design flaws there in that [the patients] maybe didn’t get what they thought was [being offered]. So maybe they thought they’d be getting treatment for insomnia, and it might not be obvious to people that mindfulness was focused on that," he added in an interview.
Dr. Espie also expressed reservations about the small sample size. "I think that to do a noninferiority trial, you need very, very large numbers because you really need to be able to demonstrate that you’ve properly tested the hypothesis and found no difference between those groups. And it was probably quite underpowered from that point of view," he said.